<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2023 Workiva-->
<!--r:8fe00145-b35d-459d-9e21-fc034645789b,g:669dfe6e-0908-42c7-a961-d34c488669ff-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.glowpoint.com/role/CONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="glow-20221231.xsd#CONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/CONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY" xlink:type="extended" id="i3eef73b404604533aaa49a27bea5fb52_CONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_f3bc4fae-ce88-4fa2-968d-123d64b4be9d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_f3bc4fae-ce88-4fa2-968d-123d64b4be9d" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_2ae115d2-f626-4fce-8ab5-0916b83d2db6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_2ae115d2-f626-4fce-8ab5-0916b83d2db6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_5608e79c-b089-4d7b-8523-02058d558b5d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_CommonStockSharesIssued_5608e79c-b089-4d7b-8523-02058d558b5d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_10c0ff78-1d03-4f7d-91f8-e0db91c52606" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_TreasuryStockCommonShares_10c0ff78-1d03-4f7d-91f8-e0db91c52606" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_19ae3dab-efbe-49f3-af0b-13ab8fe6e224" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_StockholdersEquity_19ae3dab-efbe-49f3-af0b-13ab8fe6e224" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_aa960d45-a7df-4fbb-8f76-4bbd3a57319d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_NetIncomeLoss_aa960d45-a7df-4fbb-8f76-4bbd3a57319d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_176e630d-2b66-4799-a34b-e02933336990" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_176e630d-2b66-4799-a34b-e02933336990" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_b4b55eb5-581e-40bd-9061-a594d86c6ebf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_b4b55eb5-581e-40bd-9061-a594d86c6ebf" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_44f980c1-6faf-4285-8a53-397c465fd22e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_44f980c1-6faf-4285-8a53-397c465fd22e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_5d0f2b6a-f19e-4c46-bd47-d5e6e1f92f6f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_5d0f2b6a-f19e-4c46-bd47-d5e6e1f92f6f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_549007db-af43-4279-9efd-feea7524df72" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_549007db-af43-4279-9efd-feea7524df72" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_610f7fa9-2403-4bf7-bbf7-3259244735f7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_610f7fa9-2403-4bf7-bbf7-3259244735f7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForServices_d29a8a81-cf2e-4984-bf8e-8b3991fd0a60" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForServices_d29a8a81-cf2e-4984-bf8e-8b3991fd0a60" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_StockIssuedDuringPeriodFinancingSharesNewIssues_f9f93a4d-a4c5-4e7d-8426-be345fc2f29e" xlink:href="glow-20221231.xsd#glow_StockIssuedDuringPeriodFinancingSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_glow_StockIssuedDuringPeriodFinancingSharesNewIssues_f9f93a4d-a4c5-4e7d-8426-be345fc2f29e" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_StockIssuedDuringPeriodFinancingValueNewIssues_2a237ffb-04a4-4880-b27f-a02d7d258d2f" xlink:href="glow-20221231.xsd#glow_StockIssuedDuringPeriodFinancingValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_glow_StockIssuedDuringPeriodFinancingValueNewIssues_2a237ffb-04a4-4880-b27f-a02d7d258d2f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_a7c60aa6-cd46-48bb-be53-1042f6b737f0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ba7459fe-d511-4e78-a1d7-38e39a227525" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_a7c60aa6-cd46-48bb-be53-1042f6b737f0" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_67c57530-adf7-4479-937a-4465b14aeead" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_e3e77a3e-234d-4447-bd56-912b0047c8fe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_cd2acc37-fa09-485a-83bc-4a989c105d66" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_342f9961-8c93-4af7-8712-6d151636257c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_5485ea46-f270-4183-8bc4-bb38b229e8cb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_f3bc4fae-ce88-4fa2-968d-123d64b4be9d" xlink:to="loc_us-gaap_StatementTable_5485ea46-f270-4183-8bc4-bb38b229e8cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_ab7e01ce-e6d3-41b1-b3f4-2c36e37582bb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5485ea46-f270-4183-8bc4-bb38b229e8cb" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_ab7e01ce-e6d3-41b1-b3f4-2c36e37582bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ab7e01ce-e6d3-41b1-b3f4-2c36e37582bb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ab7e01ce-e6d3-41b1-b3f4-2c36e37582bb" xlink:to="loc_us-gaap_EquityComponentDomain_ab7e01ce-e6d3-41b1-b3f4-2c36e37582bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_ab7e01ce-e6d3-41b1-b3f4-2c36e37582bb" xlink:to="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_b87dcdc8-1a8a-489a-a2b1-00988fa6c798" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:to="loc_us-gaap_PreferredStockMember_b87dcdc8-1a8a-489a-a2b1-00988fa6c798" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_6e8bccaa-e47b-4f6e-a0f2-19c1492dd614" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:to="loc_us-gaap_CommonStockMember_6e8bccaa-e47b-4f6e-a0f2-19c1492dd614" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_d330c42a-1835-4f3c-9135-08035c938f19" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:to="loc_us-gaap_TreasuryStockCommonMember_d330c42a-1835-4f3c-9135-08035c938f19" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_0aeace60-b4d2-4281-b2c1-01deab3c0056" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_0aeace60-b4d2-4281-b2c1-01deab3c0056" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_7081d379-671b-4862-aa83-8d0c63316802" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_86317a4d-5acc-4aa1-8b93-3c0e39327cd5" xlink:to="loc_us-gaap_RetainedEarningsMember_7081d379-671b-4862-aa83-8d0c63316802" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_b903ed40-5261-42c5-b638-c313b08cf46e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5485ea46-f270-4183-8bc4-bb38b229e8cb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_b903ed40-5261-42c5-b638-c313b08cf46e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_b903ed40-5261-42c5-b638-c313b08cf46e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b903ed40-5261-42c5-b638-c313b08cf46e" xlink:to="loc_us-gaap_ClassOfStockDomain_b903ed40-5261-42c5-b638-c313b08cf46e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_c8e9e2ce-a968-4ff3-9975-07be5297e1dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b903ed40-5261-42c5-b638-c313b08cf46e" xlink:to="loc_us-gaap_ClassOfStockDomain_c8e9e2ce-a968-4ff3-9975-07be5297e1dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_0d3bba98-8c20-4c7a-8a01-255ca76c6bb6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c8e9e2ce-a968-4ff3-9975-07be5297e1dd" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_0d3bba98-8c20-4c7a-8a01-255ca76c6bb6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_5b8b745a-9ce7-4463-9dce-95ddbde3bd46" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c8e9e2ce-a968-4ff3-9975-07be5297e1dd" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_5b8b745a-9ce7-4463-9dce-95ddbde3bd46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesEPreferredStockMember_40398c37-863b-4a1f-a299-236ebf50819e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesEPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c8e9e2ce-a968-4ff3-9975-07be5297e1dd" xlink:to="loc_us-gaap_SeriesEPreferredStockMember_40398c37-863b-4a1f-a299-236ebf50819e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_SeriesDEPreferredStockMember_fd7c9eb0-1e14-46ef-8409-311f7cd53627" xlink:href="glow-20221231.xsd#glow_SeriesDEPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_c8e9e2ce-a968-4ff3-9975-07be5297e1dd" xlink:to="loc_glow_SeriesDEPreferredStockMember_fd7c9eb0-1e14-46ef-8409-311f7cd53627" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/BusinessDescriptionandSignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#BusinessDescriptionandSignificantAccountingPoliciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/BusinessDescriptionandSignificantAccountingPoliciesNarrativeDetails" xlink:type="extended" id="i8315cee688af41ef9d072e544cca9b2b_BusinessDescriptionandSignificantAccountingPoliciesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_SubsidiaryInvesteeOwnershipPercentagebyParent_0a6a71f6-f700-4fc1-9822-179337b362ac" xlink:href="glow-20221231.xsd#glow_SubsidiaryInvesteeOwnershipPercentagebyParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_glow_SubsidiaryInvesteeOwnershipPercentagebyParent_0a6a71f6-f700-4fc1-9822-179337b362ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_39d5d059-7fd7-4cc2-b45f-2ef011f385e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_NumberOfOperatingSegments_39d5d059-7fd7-4cc2-b45f-2ef011f385e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_a02477de-ad26-4ef4-af34-2629312cada2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_a02477de-ad26-4ef4-af34-2629312cada2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashCurrent_e5520cf0-7240-4258-8f50-705afaaa957d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedCashCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_RestrictedCashCurrent_e5520cf0-7240-4258-8f50-705afaaa957d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_IncreaseDecreaseInOperatingExpense_70c7af76-3490-4ea9-a644-4d4cee548a1c" xlink:href="glow-20221231.xsd#glow_IncreaseDecreaseInOperatingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_glow_IncreaseDecreaseInOperatingExpense_70c7af76-3490-4ea9-a644-4d4cee548a1c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_IncreaseDecreaseInTaxCreditReceivable_9dccc002-3000-4a44-b479-656eed8b1975" xlink:href="glow-20221231.xsd#glow_IncreaseDecreaseInTaxCreditReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_glow_IncreaseDecreaseInTaxCreditReceivable_9dccc002-3000-4a44-b479-656eed8b1975" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_TaxCreditReceivable_5d621ab6-da92-46c6-9ba1-e1190f137c13" xlink:href="glow-20221231.xsd#glow_TaxCreditReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_glow_TaxCreditReceivable_5d621ab6-da92-46c6-9ba1-e1190f137c13" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_20b2609c-6ca0-4b82-8d30-b5b9ca4f8c9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_20b2609c-6ca0-4b82-8d30-b5b9ca4f8c9f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_80570d32-0e0b-4dff-b586-119d85e29b58" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_ContractWithCustomerLiability_80570d32-0e0b-4dff-b586-119d85e29b58" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_df9fa37f-dc4c-4eaf-b356-024ababae78c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_df9fa37f-dc4c-4eaf-b356-024ababae78c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExciseAndSalesTaxes_bdfca543-5b46-406d-8070-52d39eb2dcac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ExciseAndSalesTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_ExciseAndSalesTaxes_bdfca543-5b46-406d-8070-52d39eb2dcac" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_50520e75-5799-4af2-86cc-93eebd619418" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_50520e75-5799-4af2-86cc-93eebd619418" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_cf505b9e-863f-4067-9ae8-10ae8601cc5d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_cf505b9e-863f-4067-9ae8-10ae8601cc5d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ImpairmentLongLivedAssetHeldForUseNetOfGainLossOnSale_7a349c1b-f266-422c-9c49-5ce9e9aa1445" xlink:href="glow-20221231.xsd#glow_ImpairmentLongLivedAssetHeldForUseNetOfGainLossOnSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_glow_ImpairmentLongLivedAssetHeldForUseNetOfGainLossOnSale_7a349c1b-f266-422c-9c49-5ce9e9aa1445" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_7589b17f-1b40-4510-a34b-7a7d76aa3a3f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_7589b17f-1b40-4510-a34b-7a7d76aa3a3f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_24d646dd-a994-4ecf-8a41-e0fad827b0b0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_24d646dd-a994-4ecf-8a41-e0fad827b0b0" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_86921afc-fdcf-4a6f-bbef-f94cd35d6d81" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_86921afc-fdcf-4a6f-bbef-f94cd35d6d81" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_8beeecc8-45f1-476f-8273-e7d6efcc3e5d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_8beeecc8-45f1-476f-8273-e7d6efcc3e5d" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_8d7038af-4d04-45ef-a8a0-a1f6eaaa94f9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_8d7038af-4d04-45ef-a8a0-a1f6eaaa94f9" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_134431c2-570c-4af7-98c1-69d297c32c22" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_Goodwill_134431c2-570c-4af7-98c1-69d297c32c22" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_29ae15b8-98f3-4cec-bf1d-9e177be35cdf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_29ae15b8-98f3-4cec-bf1d-9e177be35cdf" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_afa222d4-ccf9-48cb-9b4d-30b97c6087aa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_afa222d4-ccf9-48cb-9b4d-30b97c6087aa" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_5c541c0e-8bde-4003-be34-2bc0d1c62e8b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_OperatingLeaseLiability_5c541c0e-8bde-4003-be34-2bc0d1c62e8b" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_53c87c0e-20d0-4932-9741-e0b809e95737" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_53c87c0e-20d0-4932-9741-e0b809e95737" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_6844d001-201b-4489-bf86-1ea37d098148" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_LesseeOperatingLeaseRenewalTerm_6844d001-201b-4489-bf86-1ea37d098148" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_52560a9e-53a0-4c19-bb5d-6f60eca405c8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives_52560a9e-53a0-4c19-bb5d-6f60eca405c8" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWriteDown_da6574ed-df9e-4e1c-ac23-04cd628a0b49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryWriteDown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_InventoryWriteDown_da6574ed-df9e-4e1c-ac23-04cd628a0b49" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuranceRecoveries_3457c7c2-8e1f-44d5-b2de-e4ed2841727d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InsuranceRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_InsuranceRecoveries_3457c7c2-8e1f-44d5-b2de-e4ed2841727d" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_5e815297-6a6d-466f-9a21-aabc0b089408" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_7171f5f8-dedd-441b-a894-7f6756e2f336" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:to="loc_srt_RangeAxis_7171f5f8-dedd-441b-a894-7f6756e2f336" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7171f5f8-dedd-441b-a894-7f6756e2f336_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_7171f5f8-dedd-441b-a894-7f6756e2f336" xlink:to="loc_srt_RangeMember_7171f5f8-dedd-441b-a894-7f6756e2f336_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_81efdee6-f435-4d60-9941-d1a228c48f96" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_7171f5f8-dedd-441b-a894-7f6756e2f336" xlink:to="loc_srt_RangeMember_81efdee6-f435-4d60-9941-d1a228c48f96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_671fe075-05f4-4dcd-8364-aef510a93cbb" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_81efdee6-f435-4d60-9941-d1a228c48f96" xlink:to="loc_srt_MinimumMember_671fe075-05f4-4dcd-8364-aef510a93cbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_39527410-73e2-4e32-9ba3-4206118237b8" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_81efdee6-f435-4d60-9941-d1a228c48f96" xlink:to="loc_srt_MaximumMember_39527410-73e2-4e32-9ba3-4206118237b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_3d037308-74bc-4f7e-8be7-8c5025938dc7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_3d037308-74bc-4f7e-8be7-8c5025938dc7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_3d037308-74bc-4f7e-8be7-8c5025938dc7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_3d037308-74bc-4f7e-8be7-8c5025938dc7" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_3d037308-74bc-4f7e-8be7-8c5025938dc7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_d0b9cc23-db8d-47b1-afb0-961b9a6678c2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_3d037308-74bc-4f7e-8be7-8c5025938dc7" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_d0b9cc23-db8d-47b1-afb0-961b9a6678c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredOverTimeMember_4ac839a0-2535-48aa-a9dc-704d9e633fc9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransferredOverTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_d0b9cc23-db8d-47b1-afb0-961b9a6678c2" xlink:to="loc_us-gaap_TransferredOverTimeMember_4ac839a0-2535-48aa-a9dc-704d9e633fc9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_e2e44c43-2491-454a-94ec-eb288878ee17" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransferredAtPointInTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_d0b9cc23-db8d-47b1-afb0-961b9a6678c2" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_e2e44c43-2491-454a-94ec-eb288878ee17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_90a6cddd-5f97-4f15-8d0f-9eb9a8b9213d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_90a6cddd-5f97-4f15-8d0f-9eb9a8b9213d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_90a6cddd-5f97-4f15-8d0f-9eb9a8b9213d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_90a6cddd-5f97-4f15-8d0f-9eb9a8b9213d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_90a6cddd-5f97-4f15-8d0f-9eb9a8b9213d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_e7d48fcc-ece0-4849-b7ea-bab6a72eba1d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_90a6cddd-5f97-4f15-8d0f-9eb9a8b9213d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_e7d48fcc-ece0-4849-b7ea-bab6a72eba1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesMember_75b4a5a5-4ac5-40a4-b34f-7c3cc7572d6b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e7d48fcc-ece0-4849-b7ea-bab6a72eba1d" xlink:to="loc_us-gaap_SalesMember_75b4a5a5-4ac5-40a4-b34f-7c3cc7572d6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_fa029d99-ec69-4fbf-8a2f-18b5f95ecb55" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e7d48fcc-ece0-4849-b7ea-bab6a72eba1d" xlink:to="loc_us-gaap_CostOfSalesMember_fa029d99-ec69-4fbf-8a2f-18b5f95ecb55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_3387bd5e-e56e-49a1-8ba2-01dbc6c452d7" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:to="loc_srt_ProductOrServiceAxis_3387bd5e-e56e-49a1-8ba2-01dbc6c452d7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_3387bd5e-e56e-49a1-8ba2-01dbc6c452d7_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_3387bd5e-e56e-49a1-8ba2-01dbc6c452d7" xlink:to="loc_srt_ProductsAndServicesDomain_3387bd5e-e56e-49a1-8ba2-01dbc6c452d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_e61c5965-eac3-440e-9977-56125959affe" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_3387bd5e-e56e-49a1-8ba2-01dbc6c452d7" xlink:to="loc_srt_ProductsAndServicesDomain_e61c5965-eac3-440e-9977-56125959affe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_1c3cd183-7646-4320-ba7a-0df7cc07bd27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_e61c5965-eac3-440e-9977-56125959affe" xlink:to="loc_us-gaap_ServiceMember_1c3cd183-7646-4320-ba7a-0df7cc07bd27" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_84b15499-8c70-46cc-bdb0-b5d8d37c98bd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_e61c5965-eac3-440e-9977-56125959affe" xlink:to="loc_us-gaap_ProductMember_84b15499-8c70-46cc-bdb0-b5d8d37c98bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_46d0d55e-cb5b-4321-a23c-c6137e3e95da" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_66ca8a9d-0f4c-4e37-a910-d26d6587c1ff" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_46d0d55e-cb5b-4321-a23c-c6137e3e95da" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_46d0d55e-cb5b-4321-a23c-c6137e3e95da_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_46d0d55e-cb5b-4321-a23c-c6137e3e95da" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_46d0d55e-cb5b-4321-a23c-c6137e3e95da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1047dc72-4ed8-4ec0-8a3a-a444a18138b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_46d0d55e-cb5b-4321-a23c-c6137e3e95da" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1047dc72-4ed8-4ec0-8a3a-a444a18138b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_dc16c1c4-1e03-4325-8ae1-c3c8d7c6916b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_1047dc72-4ed8-4ec0-8a3a-a444a18138b6" xlink:to="loc_us-gaap_SubsequentEventMember_dc16c1c4-1e03-4325-8ae1-c3c8d7c6916b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/BusinessDescriptionandSignificantAccountingPoliciesScheduleofExcessoftheFDICInsuredAmountDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#BusinessDescriptionandSignificantAccountingPoliciesScheduleofExcessoftheFDICInsuredAmountDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/BusinessDescriptionandSignificantAccountingPoliciesScheduleofExcessoftheFDICInsuredAmountDetails" xlink:type="extended" id="ia059036decfe457e93b278642d1d5ec7_BusinessDescriptionandSignificantAccountingPoliciesScheduleofExcessoftheFDICInsuredAmountDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsLineItems_5e60bcd0-873f-4cd6-be00-66ee2de5c419" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Cash_222ab80e-b340-4925-86ee-3abd6a594b9a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Cash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_5e60bcd0-873f-4cd6-be00-66ee2de5c419" xlink:to="loc_us-gaap_Cash_222ab80e-b340-4925-86ee-3abd6a594b9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFDICInsuredAmount_a03912ab-6d28-48fd-bab2-067e0b28556f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashFDICInsuredAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_5e60bcd0-873f-4cd6-be00-66ee2de5c419" xlink:to="loc_us-gaap_CashFDICInsuredAmount_a03912ab-6d28-48fd-bab2-067e0b28556f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_0c341f2e-e81c-4bc6-bb91-aa54d99b8766" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfCashAndCashEquivalentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CashAndCashEquivalentsLineItems_5e60bcd0-873f-4cd6-be00-66ee2de5c419" xlink:to="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_0c341f2e-e81c-4bc6-bb91-aa54d99b8766" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_7bb96642-9877-4b75-a1ea-7929657876d3" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCashAndCashEquivalentsTable_0c341f2e-e81c-4bc6-bb91-aa54d99b8766" xlink:to="loc_srt_CounterpartyNameAxis_7bb96642-9877-4b75-a1ea-7929657876d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7bb96642-9877-4b75-a1ea-7929657876d3_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_7bb96642-9877-4b75-a1ea-7929657876d3" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_7bb96642-9877-4b75-a1ea-7929657876d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9988bc4e-2f65-43ab-89d8-5458a4545c2b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_7bb96642-9877-4b75-a1ea-7929657876d3" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9988bc4e-2f65-43ab-89d8-5458a4545c2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_SiliconValleyBankMember_0cbef36a-c1f6-45f8-8d9a-d1f0d88aba9f" xlink:href="glow-20221231.xsd#glow_SiliconValleyBankMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9988bc4e-2f65-43ab-89d8-5458a4545c2b" xlink:to="loc_glow_SiliconValleyBankMember_0cbef36a-c1f6-45f8-8d9a-d1f0d88aba9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_MorganStanleyMember_89937d19-2933-46c2-a936-0880cc912968" xlink:href="glow-20221231.xsd#glow_MorganStanleyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9988bc4e-2f65-43ab-89d8-5458a4545c2b" xlink:to="loc_glow_MorganStanleyMember_89937d19-2933-46c2-a936-0880cc912968" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ResolveGroupUKMember_dca4cbbf-ea97-457e-972b-6ac4a69615ae" xlink:href="glow-20221231.xsd#glow_ResolveGroupUKMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_9988bc4e-2f65-43ab-89d8-5458a4545c2b" xlink:to="loc_glow_ResolveGroupUKMember_dca4cbbf-ea97-457e-972b-6ac4a69615ae" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/PropertyandEquipmentScheduleofPropertyandEquipmentDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#PropertyandEquipmentScheduleofPropertyandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/PropertyandEquipmentScheduleofPropertyandEquipmentDetails" xlink:type="extended" id="ib5940dcf3cbe400c81aa953c51308501_PropertyandEquipmentScheduleofPropertyandEquipmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_01361b71-20ad-4b1e-94f7-f77f49455654" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_d4884b87-eb46-4784-8f94-f2e36bd99324" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_01361b71-20ad-4b1e-94f7-f77f49455654" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_d4884b87-eb46-4784-8f94-f2e36bd99324" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_82180028-e2e7-4a66-85b4-75ca6101ff8d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_01361b71-20ad-4b1e-94f7-f77f49455654" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_82180028-e2e7-4a66-85b4-75ca6101ff8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_61a2f5fb-ed13-49fc-a1b5-39acc62d509b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_01361b71-20ad-4b1e-94f7-f77f49455654" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_61a2f5fb-ed13-49fc-a1b5-39acc62d509b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_a6656d26-b9c9-49da-9623-a876c48b31af" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_01361b71-20ad-4b1e-94f7-f77f49455654" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_a6656d26-b9c9-49da-9623-a876c48b31af" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_04518812-6292-41ac-ac2f-b16108dc52a1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_01361b71-20ad-4b1e-94f7-f77f49455654" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_04518812-6292-41ac-ac2f-b16108dc52a1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_57da4f17-be0f-4191-8b2a-aaa1deb1cf6e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_04518812-6292-41ac-ac2f-b16108dc52a1" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_57da4f17-be0f-4191-8b2a-aaa1deb1cf6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_57da4f17-be0f-4191-8b2a-aaa1deb1cf6e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_57da4f17-be0f-4191-8b2a-aaa1deb1cf6e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_57da4f17-be0f-4191-8b2a-aaa1deb1cf6e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fbb1271-94ac-4eee-973f-ce4d88c5f240" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_57da4f17-be0f-4191-8b2a-aaa1deb1cf6e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fbb1271-94ac-4eee-973f-ce4d88c5f240" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_NetworkEquipmentAndSoftwareMember_2f272195-5c84-4fb6-b122-ecd45ae8db49" xlink:href="glow-20221231.xsd#glow_NetworkEquipmentAndSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fbb1271-94ac-4eee-973f-ce4d88c5f240" xlink:to="loc_glow_NetworkEquipmentAndSoftwareMember_2f272195-5c84-4fb6-b122-ecd45ae8db49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ComputerEquipmentAndSoftwareMember_9ab720e0-2e42-48f7-b65e-f33f42ee37bf" xlink:href="glow-20221231.xsd#glow_ComputerEquipmentAndSoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fbb1271-94ac-4eee-973f-ce4d88c5f240" xlink:to="loc_glow_ComputerEquipmentAndSoftwareMember_9ab720e0-2e42-48f7-b65e-f33f42ee37bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_40072a0b-060b-482c-bec8-73b37cd12977" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fbb1271-94ac-4eee-973f-ce4d88c5f240" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_40072a0b-060b-482c-bec8-73b37cd12977" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_323b20aa-3e23-46ac-885d-cd289fd69dcc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8fbb1271-94ac-4eee-973f-ce4d88c5f240" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_323b20aa-3e23-46ac-885d-cd289fd69dcc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_7188d3a5-f726-44b4-b0c4-99fb444e3be3" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_04518812-6292-41ac-ac2f-b16108dc52a1" xlink:to="loc_srt_RangeAxis_7188d3a5-f726-44b4-b0c4-99fb444e3be3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7188d3a5-f726-44b4-b0c4-99fb444e3be3_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_7188d3a5-f726-44b4-b0c4-99fb444e3be3" xlink:to="loc_srt_RangeMember_7188d3a5-f726-44b4-b0c4-99fb444e3be3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b2a49e5c-6a98-45fa-a747-93dcdc52eaba" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_7188d3a5-f726-44b4-b0c4-99fb444e3be3" xlink:to="loc_srt_RangeMember_b2a49e5c-6a98-45fa-a747-93dcdc52eaba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_22c4b41b-111d-46ba-b9c1-4591eb4e91cc" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b2a49e5c-6a98-45fa-a747-93dcdc52eaba" xlink:to="loc_srt_MinimumMember_22c4b41b-111d-46ba-b9c1-4591eb4e91cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_6aea81e6-eef8-4bd9-8608-31728c5e87b8" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b2a49e5c-6a98-45fa-a747-93dcdc52eaba" xlink:to="loc_srt_MaximumMember_6aea81e6-eef8-4bd9-8608-31728c5e87b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_6f090eec-a784-4ecb-8dd0-5935b70aba51" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_04518812-6292-41ac-ac2f-b16108dc52a1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_6f090eec-a784-4ecb-8dd0-5935b70aba51" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_6f090eec-a784-4ecb-8dd0-5935b70aba51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6f090eec-a784-4ecb-8dd0-5935b70aba51" xlink:to="loc_us-gaap_SegmentDomain_6f090eec-a784-4ecb-8dd0-5935b70aba51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9e6400d6-6718-43f4-817b-4730071adf29" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_6f090eec-a784-4ecb-8dd0-5935b70aba51" xlink:to="loc_us-gaap_SegmentDomain_9e6400d6-6718-43f4-817b-4730071adf29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CollaborationProductsMember_30629741-6af9-4298-a76e-4e12fd457e75" xlink:href="glow-20221231.xsd#glow_CollaborationProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9e6400d6-6718-43f4-817b-4730071adf29" xlink:to="loc_glow_CollaborationProductsMember_30629741-6af9-4298-a76e-4e12fd457e75" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/PropertyandEquipmentNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#PropertyandEquipmentNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/PropertyandEquipmentNarrativeDetails" xlink:type="extended" id="if6389d37c9b742d2a1faae1ec018432b_PropertyandEquipmentNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDepreciationAndAmortization_2c8833e7-cc29-4e03-a313-81714a002fdd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_OtherDepreciationAndAmortization_2c8833e7-cc29-4e03-a313-81714a002fdd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentDisposals_059690b0-c12a-42ef-9fef-9bf83ed4802a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentDisposals"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentDisposals_059690b0-c12a-42ef-9fef-9bf83ed4802a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationSaleOfPropertyPlantAndEquipment1_d777d89a-ba24-4af3-8343-553e78b4ee04" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationSaleOfPropertyPlantAndEquipment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationSaleOfPropertyPlantAndEquipment1_d777d89a-ba24-4af3-8343-553e78b4ee04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_60ef5c8e-3325-4d8b-be66-e8069ae06933" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_60ef5c8e-3325-4d8b-be66-e8069ae06933" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_853e4140-56a4-424a-a622-43dd430960e3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_853e4140-56a4-424a-a622-43dd430960e3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_192566ec-15e6-437e-895b-6125dc6e9279" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_Depreciation_192566ec-15e6-437e-895b-6125dc6e9279" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_d597f144-cd44-4697-8754-a33c21fe8318" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_d597f144-cd44-4697-8754-a33c21fe8318" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TangibleAssetImpairmentCharges_e12037d6-6215-45f0-a865-588e93bfbd8a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TangibleAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_TangibleAssetImpairmentCharges_e12037d6-6215-45f0-a865-588e93bfbd8a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cf8d4249-16f5-4ba3-9380-2eface35d131" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_14419606-e17c-48dc-8eda-cab5380ebb7b" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cf8d4249-16f5-4ba3-9380-2eface35d131" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_30628ae8-2f72-4af4-9b58-b41123f59515" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_cf8d4249-16f5-4ba3-9380-2eface35d131" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_30628ae8-2f72-4af4-9b58-b41123f59515" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_30628ae8-2f72-4af4-9b58-b41123f59515_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_30628ae8-2f72-4af4-9b58-b41123f59515" xlink:to="loc_us-gaap_SegmentDomain_30628ae8-2f72-4af4-9b58-b41123f59515_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_7e6fa1ee-142c-450e-bb7e-0bc88eeb8d49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_30628ae8-2f72-4af4-9b58-b41123f59515" xlink:to="loc_us-gaap_SegmentDomain_7e6fa1ee-142c-450e-bb7e-0bc88eeb8d49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CollaborationProductsMember_a174a4cc-fc18-49ea-bd46-3dc089c351b7" xlink:href="glow-20221231.xsd#glow_CollaborationProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_7e6fa1ee-142c-450e-bb7e-0bc88eeb8d49" xlink:to="loc_glow_CollaborationProductsMember_a174a4cc-fc18-49ea-bd46-3dc089c351b7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/IntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#IntangibleAssetsScheduleofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/IntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="extended" id="ib850f5c987524cff85f45c3d35047204_IntangibleAssetsScheduleofIntangibleAssetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_53d363e0-7ffe-4215-ba4b-adfb2e8c2af5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_7be36cfd-47ef-4935-9402-57d847227a80" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_53d363e0-7ffe-4215-ba4b-adfb2e8c2af5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_7be36cfd-47ef-4935-9402-57d847227a80" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_910bf67d-ecaf-4f91-bb9a-d16716de3f4e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_53d363e0-7ffe-4215-ba4b-adfb2e8c2af5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_910bf67d-ecaf-4f91-bb9a-d16716de3f4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_79a02481-e541-444a-a09e-a2d98571a812" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_53d363e0-7ffe-4215-ba4b-adfb2e8c2af5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_79a02481-e541-444a-a09e-a2d98571a812" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a769b26b-1951-4ae4-90da-58f49f0e9f2d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_53d363e0-7ffe-4215-ba4b-adfb2e8c2af5" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a769b26b-1951-4ae4-90da-58f49f0e9f2d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52c022a8-c4ae-415a-823d-35d64fdac713" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a769b26b-1951-4ae4-90da-58f49f0e9f2d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52c022a8-c4ae-415a-823d-35d64fdac713" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_52c022a8-c4ae-415a-823d-35d64fdac713_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52c022a8-c4ae-415a-823d-35d64fdac713" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_52c022a8-c4ae-415a-823d-35d64fdac713_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4d122568-2299-4e7d-9cc5-cca9a8e38e52" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52c022a8-c4ae-415a-823d-35d64fdac713" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4d122568-2299-4e7d-9cc5-cca9a8e38e52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_0bdb6fd7-1d5a-417a-a82d-dcd54b040fe5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4d122568-2299-4e7d-9cc5-cca9a8e38e52" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_0bdb6fd7-1d5a-417a-a82d-dcd54b040fe5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_e938f763-fd60-46b7-8fab-ee721d0ef931" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4d122568-2299-4e7d-9cc5-cca9a8e38e52" xlink:to="loc_us-gaap_TradeNamesMember_e938f763-fd60-46b7-8fab-ee721d0ef931" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_8488699d-f9cb-4301-b15f-0ad00d55d6d6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4d122568-2299-4e7d-9cc5-cca9a8e38e52" xlink:to="loc_us-gaap_CustomerRelationshipsMember_8488699d-f9cb-4301-b15f-0ad00d55d6d6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/IntangibleAssetsNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#IntangibleAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/IntangibleAssetsNarrativeDetails" xlink:type="extended" id="i7bad336e095245149518c0fdfc12ad26_IntangibleAssetsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_95396e8c-c623-49b4-a93f-927955db390b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_d78a2064-1207-4511-ad64-28c0cf1fab7d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_95396e8c-c623-49b4-a93f-927955db390b" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsFinitelived_d78a2064-1207-4511-ad64-28c0cf1fab7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_a5ccf28f-22a7-4bee-9d1c-48d0a437922e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_95396e8c-c623-49b4-a93f-927955db390b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_a5ccf28f-22a7-4bee-9d1c-48d0a437922e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_76a0b1e7-9e99-4283-9599-e5085fc19240" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_95396e8c-c623-49b4-a93f-927955db390b" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_76a0b1e7-9e99-4283-9599-e5085fc19240" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a37979d4-e219-472e-b715-60bd58a7b594" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_95396e8c-c623-49b4-a93f-927955db390b" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a37979d4-e219-472e-b715-60bd58a7b594" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_038865f9-f367-4a51-840e-ea2ca9e89e45" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_a37979d4-e219-472e-b715-60bd58a7b594" xlink:to="loc_srt_RangeAxis_038865f9-f367-4a51-840e-ea2ca9e89e45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_038865f9-f367-4a51-840e-ea2ca9e89e45_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_038865f9-f367-4a51-840e-ea2ca9e89e45" xlink:to="loc_srt_RangeMember_038865f9-f367-4a51-840e-ea2ca9e89e45_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b54ac1e8-66c3-4282-a961-22bb6a24da77" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_038865f9-f367-4a51-840e-ea2ca9e89e45" xlink:to="loc_srt_RangeMember_b54ac1e8-66c3-4282-a961-22bb6a24da77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_250d0611-a18d-4f05-bc2a-e2cf07a7ca88" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b54ac1e8-66c3-4282-a961-22bb6a24da77" xlink:to="loc_srt_MinimumMember_250d0611-a18d-4f05-bc2a-e2cf07a7ca88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a6a96210-2b3e-4ba0-83b5-4535217437f7" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_b54ac1e8-66c3-4282-a961-22bb6a24da77" xlink:to="loc_srt_MaximumMember_a6a96210-2b3e-4ba0-83b5-4535217437f7" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/OperatingLeaseLiabilitiesandRightofUseAssetsNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#OperatingLeaseLiabilitiesandRightofUseAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/OperatingLeaseLiabilitiesandRightofUseAssetsNarrativeDetails" xlink:type="extended" id="ifdd1a7bfb5a34b3d8b147be1e0022760_OperatingLeaseLiabilitiesandRightofUseAssetsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_NumberOfFacilities_07e3eb43-9a7c-4e9c-ad6d-b3c8402f5554" xlink:href="glow-20221231.xsd#glow_NumberOfFacilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_glow_NumberOfFacilities_07e3eb43-9a7c-4e9c-ad6d-b3c8402f5554" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_LeasesNumberOfSubleases_97b2d9e7-aced-4116-9915-8b7bf2af2640" xlink:href="glow-20221231.xsd#glow_LeasesNumberOfSubleases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_glow_LeasesNumberOfSubleases_97b2d9e7-aced-4116-9915-8b7bf2af2640" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_LeasesNumberOfImpairedRightOfUseProperties_c3f2bb98-e582-4211-a0c6-394f7fe00954" xlink:href="glow-20221231.xsd#glow_LeasesNumberOfImpairedRightOfUseProperties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_glow_LeasesNumberOfImpairedRightOfUseProperties_c3f2bb98-e582-4211-a0c6-394f7fe00954" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseExpense_96beacf8-293b-4594-be56-660d8a4647ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_OperatingLeaseExpense_96beacf8-293b-4594-be56-660d8a4647ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_25cf04ba-4346-45a0-a1d5-135609d2b1d6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubleaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_SubleaseIncome_25cf04ba-4346-45a0-a1d5-135609d2b1d6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_c08bb3e4-ec70-43b1-a837-690f106c8f80" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_c08bb3e4-ec70-43b1-a837-690f106c8f80" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_2c14739c-1e62-4e09-b235-544c355e8879" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_2c14739c-1e62-4e09-b235-544c355e8879" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_2ab35c83-498b-4482-97e8-6f43f336a7fa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_OperatingLeaseLiability_2ab35c83-498b-4482-97e8-6f43f336a7fa" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_7d21eb49-6dbd-4310-84a7-df51036f2968" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_7d21eb49-6dbd-4310-84a7-df51036f2968" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_NumberOfLeasesTerminated_82228a19-f60a-439c-a738-7cf0bd6cfa5b" xlink:href="glow-20221231.xsd#glow_NumberOfLeasesTerminated"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_glow_NumberOfLeasesTerminated_82228a19-f60a-439c-a738-7cf0bd6cfa5b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_641f0420-eedb-4eba-bc9a-9cdd9f41b158" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_1af6ceba-788b-4e4d-8b4f-7a69c18acb0f" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_641f0420-eedb-4eba-bc9a-9cdd9f41b158" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_9f1a0611-7787-49ac-9c3f-20b5df9eb9d9" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_641f0420-eedb-4eba-bc9a-9cdd9f41b158" xlink:to="loc_srt_StatementGeographicalAxis_9f1a0611-7787-49ac-9c3f-20b5df9eb9d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_9f1a0611-7787-49ac-9c3f-20b5df9eb9d9_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_9f1a0611-7787-49ac-9c3f-20b5df9eb9d9" xlink:to="loc_srt_SegmentGeographicalDomain_9f1a0611-7787-49ac-9c3f-20b5df9eb9d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_b39349cd-60d2-49ea-8ee5-5cb507156686" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_9f1a0611-7787-49ac-9c3f-20b5df9eb9d9" xlink:to="loc_srt_SegmentGeographicalDomain_b39349cd-60d2-49ea-8ee5-5cb507156686" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_LosAngelesCaliforniaMember_4faa412f-96da-4410-b0c5-bf6b59d79f13" xlink:href="glow-20221231.xsd#glow_LosAngelesCaliforniaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b39349cd-60d2-49ea-8ee5-5cb507156686" xlink:to="loc_glow_LosAngelesCaliforniaMember_4faa412f-96da-4410-b0c5-bf6b59d79f13" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CityOfIndustryCaliforniaMember_4f3bc06a-a3c2-4698-9619-fef05c611d38" xlink:href="glow-20221231.xsd#glow_CityOfIndustryCaliforniaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b39349cd-60d2-49ea-8ee5-5cb507156686" xlink:to="loc_glow_CityOfIndustryCaliforniaMember_4f3bc06a-a3c2-4698-9619-fef05c611d38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_DallasTexasMember_6ef6979e-b255-41ee-a814-ef312be983d3" xlink:href="glow-20221231.xsd#glow_DallasTexasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b39349cd-60d2-49ea-8ee5-5cb507156686" xlink:to="loc_glow_DallasTexasMember_6ef6979e-b255-41ee-a814-ef312be983d3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_BostonMassachusettsMember_c75bf02f-0cde-4346-89ba-31f0900d20a0" xlink:href="glow-20221231.xsd#glow_BostonMassachusettsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b39349cd-60d2-49ea-8ee5-5cb507156686" xlink:to="loc_glow_BostonMassachusettsMember_c75bf02f-0cde-4346-89ba-31f0900d20a0" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/CapitalStockCommonStockDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#CapitalStockCommonStockDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/CapitalStockCommonStockDetails" xlink:type="extended" id="ic15773e0b6d1473f8573448bbf8fcfa8_CapitalStockCommonStockDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_fe6f2a0b-f3c0-4f21-ba92-35970492683a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_fe6f2a0b-f3c0-4f21-ba92-35970492683a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_773c7766-913b-4c21-9e29-fd11c4fac39b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_773c7766-913b-4c21-9e29-fd11c4fac39b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_10dbcb3e-3c96-4ad8-a49a-585343028645" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_10dbcb3e-3c96-4ad8-a49a-585343028645" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_ab5a55c6-568e-4eb4-b1ae-e43853df70d3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:to="loc_us-gaap_CommonStockSharesIssued_ab5a55c6-568e-4eb4-b1ae-e43853df70d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_7f13f39a-33cd-4078-aafb-fd745a71c0f7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_7f13f39a-33cd-4078-aafb-fd745a71c0f7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_8c449709-8f0b-4496-9136-ef55e009f29c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_62eed46d-4979-4116-b661-d8a27fe4ed6a" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_8c449709-8f0b-4496-9136-ef55e009f29c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_bd93e8fd-a3ca-4fa7-bf34-d836725f0de5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_8c449709-8f0b-4496-9136-ef55e009f29c" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_bd93e8fd-a3ca-4fa7-bf34-d836725f0de5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_bd93e8fd-a3ca-4fa7-bf34-d836725f0de5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_bd93e8fd-a3ca-4fa7-bf34-d836725f0de5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_bd93e8fd-a3ca-4fa7-bf34-d836725f0de5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_f16fae75-fcc5-4d84-8990-ef14753a296b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_bd93e8fd-a3ca-4fa7-bf34-d836725f0de5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_f16fae75-fcc5-4d84-8990-ef14753a296b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_30e3cde0-d8e2-470b-a157-949ff8972650" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_f16fae75-fcc5-4d84-8990-ef14753a296b" xlink:to="loc_us-gaap_SubsequentEventMember_30e3cde0-d8e2-470b-a157-949ff8972650" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/CapitalStockCommonStockActivityDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#CapitalStockCommonStockActivityDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/CapitalStockCommonStockActivityDetails" xlink:type="extended" id="ia92862551ece425f922d648e26c37acc_CapitalStockCommonStockActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_42f1c156-8402-47a1-8c0a-3f45fe60a89b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_42f1c156-8402-47a1-8c0a-3f45fe60a89b" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_c8db305f-475d-40d5-82a7-9450e9c9036a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:to="loc_us-gaap_SharesIssued_c8db305f-475d-40d5-82a7-9450e9c9036a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_StockIssuedDuringPeriodFinancingSharesNewIssues_4b62fb0d-07ce-4b9d-94ab-1ff956ff2e8f" xlink:href="glow-20221231.xsd#glow_StockIssuedDuringPeriodFinancingSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:to="loc_glow_StockIssuedDuringPeriodFinancingSharesNewIssues_4b62fb0d-07ce-4b9d-94ab-1ff956ff2e8f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_c1949069-6cc9-412c-8570-4211a9aa4c2a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_c1949069-6cc9-412c-8570-4211a9aa4c2a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_97f3fce0-b860-4067-9591-17aa2b4a404a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_97f3fce0-b860-4067-9591-17aa2b4a404a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_d2c3f1d8-9414-4db5-82bd-8659931ed899" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_d2c3f1d8-9414-4db5-82bd-8659931ed899" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockShares_8f212abc-183b-45db-8357-a7e989260289" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_246ae135-1c4c-426e-a520-3ae1b8d6cc94" xlink:to="loc_us-gaap_TreasuryStockShares_8f212abc-183b-45db-8357-a7e989260289" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_25e71c50-4537-4dc6-89f6-c13852a227d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_75f586fc-6511-4a06-a1b4-65d927343252" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_b1e1cde0-dcea-4803-996c-2c5225f53008" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_42f1c156-8402-47a1-8c0a-3f45fe60a89b" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_b1e1cde0-dcea-4803-996c-2c5225f53008" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_05a03118-bff7-4d80-be9e-efa8510386d9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_42f1c156-8402-47a1-8c0a-3f45fe60a89b" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_05a03118-bff7-4d80-be9e-efa8510386d9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3febcbf6-6437-4d8d-aeaa-8a4884018aef" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_05a03118-bff7-4d80-be9e-efa8510386d9" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3febcbf6-6437-4d8d-aeaa-8a4884018aef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_3febcbf6-6437-4d8d-aeaa-8a4884018aef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3febcbf6-6437-4d8d-aeaa-8a4884018aef" xlink:to="loc_us-gaap_EquityComponentDomain_3febcbf6-6437-4d8d-aeaa-8a4884018aef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ec8194e5-c6ae-4859-9f3b-e143206c2e06" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3febcbf6-6437-4d8d-aeaa-8a4884018aef" xlink:to="loc_us-gaap_EquityComponentDomain_ec8194e5-c6ae-4859-9f3b-e143206c2e06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_a620b1db-dbc6-40d2-a1fb-51e375b6a251" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_ec8194e5-c6ae-4859-9f3b-e143206c2e06" xlink:to="loc_us-gaap_CommonStockMember_a620b1db-dbc6-40d2-a1fb-51e375b6a251" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/CapitalStockAdditionalInformationDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#CapitalStockAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/CapitalStockAdditionalInformationDetails" xlink:type="extended" id="ic29a5d5a39a04e22a9af3f61b4392132_CapitalStockAdditionalInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_ea3a2ef0-e4d0-4394-8a4a-adcd0afdc1b2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_ea3a2ef0-e4d0-4394-8a4a-adcd0afdc1b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_0e5e3830-9226-45d5-8ef1-505c01438077" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_0e5e3830-9226-45d5-8ef1-505c01438077" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForServices_966ef940-4d6f-4b4b-b2cb-bf31af5f8ab1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueIssuedForServices_966ef940-4d6f-4b4b-b2cb-bf31af5f8ab1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_0485deb0-2c3c-4280-80a0-a99e7e386838" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_0485deb0-2c3c-4280-80a0-a99e7e386838" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_097dba5a-8fb5-45ec-90d1-fec515e7d996" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_097dba5a-8fb5-45ec-90d1-fec515e7d996" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_4ac213a0-8652-4f37-afd7-010148f687e9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_4ac213a0-8652-4f37-afd7-010148f687e9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_248851a3-1dec-4514-a2e3-9b183777d844" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_248851a3-1dec-4514-a2e3-9b183777d844" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_0d059727-f2a7-4d4f-baed-26d4e60ced7f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_0d059727-f2a7-4d4f-baed-26d4e60ced7f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOrSaleOfEquity_460da4db-6fca-4233-93a2-3cde7e57fea6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_ProceedsFromIssuanceOrSaleOfEquity_460da4db-6fca-4233-93a2-3cde7e57fea6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_ca254bbc-84b8-444b-b8de-17faa96bfdb3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_ca254bbc-84b8-444b-b8de-17faa96bfdb3" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1cb483c3-bd1d-4b3c-91c7-1d093c0c7cbf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1cb483c3-bd1d-4b3c-91c7-1d093c0c7cbf" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ClassOfWarrantOrRightExerciseOfWarrants_f8e0c614-d96d-4235-bb1e-5c415dcf97da" xlink:href="glow-20221231.xsd#glow_ClassOfWarrantOrRightExerciseOfWarrants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_glow_ClassOfWarrantOrRightExerciseOfWarrants_f8e0c614-d96d-4235-bb1e-5c415dcf97da" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantDownRoundFeatureIncreaseDecreaseInEquityAmount1_9596e16e-1d78-40dd-86f2-5ed1943696cb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantDownRoundFeatureIncreaseDecreaseInEquityAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_WarrantDownRoundFeatureIncreaseDecreaseInEquityAmount1_9596e16e-1d78-40dd-86f2-5ed1943696cb" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_39a0d150-c0c2-411d-a20e-deb2b144b833" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_TreasuryStockCommonShares_39a0d150-c0c2-411d-a20e-deb2b144b833" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_efaa2288-2b35-4be8-9a24-4ee6bc4aa9b3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_0edb9c55-4ae3-4df3-8b73-6b6cce1d0d33" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_efaa2288-2b35-4be8-9a24-4ee6bc4aa9b3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_e7bde87d-d988-4135-86c0-b18abb222c62" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_efaa2288-2b35-4be8-9a24-4ee6bc4aa9b3" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_e7bde87d-d988-4135-86c0-b18abb222c62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e7bde87d-d988-4135-86c0-b18abb222c62_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e7bde87d-d988-4135-86c0-b18abb222c62" xlink:to="loc_us-gaap_EquityComponentDomain_e7bde87d-d988-4135-86c0-b18abb222c62_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_190c63d2-5417-49ca-a556-dbe2f0a53af2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e7bde87d-d988-4135-86c0-b18abb222c62" xlink:to="loc_us-gaap_EquityComponentDomain_190c63d2-5417-49ca-a556-dbe2f0a53af2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_2e04b4ea-202a-4dcc-a191-260a150bf8df" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_190c63d2-5417-49ca-a556-dbe2f0a53af2" xlink:to="loc_us-gaap_CommonStockMember_2e04b4ea-202a-4dcc-a191-260a150bf8df" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_afe35a36-a98a-4323-8153-bb28a1cf776c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_190c63d2-5417-49ca-a556-dbe2f0a53af2" xlink:to="loc_us-gaap_WarrantMember_afe35a36-a98a-4323-8153-bb28a1cf776c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_32131514-1fc4-438d-901c-9cf9a1630b88" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_efaa2288-2b35-4be8-9a24-4ee6bc4aa9b3" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_32131514-1fc4-438d-901c-9cf9a1630b88" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_32131514-1fc4-438d-901c-9cf9a1630b88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_32131514-1fc4-438d-901c-9cf9a1630b88" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_32131514-1fc4-438d-901c-9cf9a1630b88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_60b49710-9699-4e95-8a9c-64fa37a8909b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_32131514-1fc4-438d-901c-9cf9a1630b88" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_60b49710-9699-4e95-8a9c-64fa37a8909b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_dfd002b6-505e-4121-a03e-4d50c58f4c1b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_60b49710-9699-4e95-8a9c-64fa37a8909b" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_dfd002b6-505e-4121-a03e-4d50c58f4c1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_72f5c101-119b-49ac-9a92-4a04fdbf520d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_efaa2288-2b35-4be8-9a24-4ee6bc4aa9b3" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_72f5c101-119b-49ac-9a92-4a04fdbf520d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_72f5c101-119b-49ac-9a92-4a04fdbf520d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_72f5c101-119b-49ac-9a92-4a04fdbf520d" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_72f5c101-119b-49ac-9a92-4a04fdbf520d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_aac227f6-d8bf-4e00-80f0-28c9ea708b5b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_72f5c101-119b-49ac-9a92-4a04fdbf520d" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_aac227f6-d8bf-4e00-80f0-28c9ea708b5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_PublicOfferingMember_4b461b61-e1cd-4ee1-b872-496431dc2a43" xlink:href="glow-20221231.xsd#glow_PublicOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_aac227f6-d8bf-4e00-80f0-28c9ea708b5b" xlink:to="loc_glow_PublicOfferingMember_4b461b61-e1cd-4ee1-b872-496431dc2a43" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivatePlacementMember_7261ab0a-94c2-4e6f-a73a-c39dff0fd872" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PrivatePlacementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_aac227f6-d8bf-4e00-80f0-28c9ea708b5b" xlink:to="loc_us-gaap_PrivatePlacementMember_7261ab0a-94c2-4e6f-a73a-c39dff0fd872" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/CapitalStockWarrantsOutstandingDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#CapitalStockWarrantsOutstandingDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/CapitalStockWarrantsOutstandingDetails" xlink:type="extended" id="i21835868f0cd4c0d89bd18a60784059c_CapitalStockWarrantsOutstandingDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_82a104e9-42d8-4267-a31d-b8828fc0d4af" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ClassOfWarrantOrRightIssued_c0ec5113-7ec4-4c3a-bc24-b72c0a776adb" xlink:href="glow-20221231.xsd#glow_ClassOfWarrantOrRightIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_82a104e9-42d8-4267-a31d-b8828fc0d4af" xlink:to="loc_glow_ClassOfWarrantOrRightIssued_c0ec5113-7ec4-4c3a-bc24-b72c0a776adb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_3321c1cd-77e3-4bcb-8d56-d2d2538c769b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_82a104e9-42d8-4267-a31d-b8828fc0d4af" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_3321c1cd-77e3-4bcb-8d56-d2d2538c769b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_d0e4a4dd-d6ca-47e5-a0ed-142552609eef" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_82a104e9-42d8-4267-a31d-b8828fc0d4af" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_d0e4a4dd-d6ca-47e5-a0ed-142552609eef" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_85bb5558-acb1-4183-979d-79cbfe2588f2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_d0e4a4dd-d6ca-47e5-a0ed-142552609eef" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_85bb5558-acb1-4183-979d-79cbfe2588f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_85bb5558-acb1-4183-979d-79cbfe2588f2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_85bb5558-acb1-4183-979d-79cbfe2588f2" xlink:to="loc_us-gaap_EquityComponentDomain_85bb5558-acb1-4183-979d-79cbfe2588f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e9a41705-99e2-4593-bf3b-18e4091a9e43" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_85bb5558-acb1-4183-979d-79cbfe2588f2" xlink:to="loc_us-gaap_EquityComponentDomain_e9a41705-99e2-4593-bf3b-18e4091a9e43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_31cc4b24-1e51-4b6d-ac2d-02e75e6775d8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e9a41705-99e2-4593-bf3b-18e4091a9e43" xlink:to="loc_us-gaap_WarrantMember_31cc4b24-1e51-4b6d-ac2d-02e75e6775d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_6576515e-de21-4ac5-a142-672cb70ddfcc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e9a41705-99e2-4593-bf3b-18e4091a9e43" xlink:to="loc_us-gaap_CommonStockMember_6576515e-de21-4ac5-a142-672cb70ddfcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_078ad12c-bb5f-402c-814d-46e6d74c618c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_d0e4a4dd-d6ca-47e5-a0ed-142552609eef" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_078ad12c-bb5f-402c-814d-46e6d74c618c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_078ad12c-bb5f-402c-814d-46e6d74c618c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_078ad12c-bb5f-402c-814d-46e6d74c618c" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_078ad12c-bb5f-402c-814d-46e6d74c618c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_40b503d1-1832-4782-aead-548b7de0cc76" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_078ad12c-bb5f-402c-814d-46e6d74c618c" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_40b503d1-1832-4782-aead-548b7de0cc76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_PublicOfferingMember_73fb4242-d461-4341-824a-d0e2295423b7" xlink:href="glow-20221231.xsd#glow_PublicOfferingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_40b503d1-1832-4782-aead-548b7de0cc76" xlink:to="loc_glow_PublicOfferingMember_73fb4242-d461-4341-824a-d0e2295423b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivatePlacementMember_4e268368-c93f-4200-9de7-ab0fc7fe60bd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PrivatePlacementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_40b503d1-1832-4782-aead-548b7de0cc76" xlink:to="loc_us-gaap_PrivatePlacementMember_4e268368-c93f-4200-9de7-ab0fc7fe60bd" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/PreferredStockDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#PreferredStockDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/PreferredStockDetails" xlink:type="extended" id="ia668a8c524864366a09186b8ee0722e9_PreferredStockDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_6d4c6617-0f0d-41b5-8732-dda9feedc9f4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_6d4c6617-0f0d-41b5-8732-dda9feedc9f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_65f2fe60-867d-476f-aa74-fe59af001f98" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_65f2fe60-867d-476f-aa74-fe59af001f98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_ad971bb5-4018-4f1f-9734-aec4d62d45e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_PreferredStockSharesIssued_ad971bb5-4018-4f1f-9734-aec4d62d45e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_b8d86313-98ef-47b0-bf83-7f54c008f15b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_b8d86313-98ef-47b0-bf83-7f54c008f15b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockSharesIssued1_5eadd673-5e72-4968-a415-e12051fd0d98" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConversionOfStockSharesIssued1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_ConversionOfStockSharesIssued1_5eadd673-5e72-4968-a415-e12051fd0d98" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_StockIssuedDuringPeriodConversionOfConvertibleSecuritiesPrice_aad4cb1a-d415-474b-8e18-b614da97467d" xlink:href="glow-20221231.xsd#glow_StockIssuedDuringPeriodConversionOfConvertibleSecuritiesPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_glow_StockIssuedDuringPeriodConversionOfConvertibleSecuritiesPrice_aad4cb1a-d415-474b-8e18-b614da97467d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_1e088033-f7bd-443c-a678-e61b036cbef1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_1e088033-f7bd-443c-a678-e61b036cbef1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_cd7d5315-c2e3-4d9d-b502-35d406b94c25" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_cd7d5315-c2e3-4d9d-b502-35d406b94c25" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_56383747-bf91-42c8-925a-98b95e9517f0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_72012c74-72c8-46dd-99d9-b7267677c659" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_56383747-bf91-42c8-925a-98b95e9517f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_48a3acec-468e-41a5-8d70-bec392a001e5" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_56383747-bf91-42c8-925a-98b95e9517f0" xlink:to="loc_srt_RangeAxis_48a3acec-468e-41a5-8d70-bec392a001e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_48a3acec-468e-41a5-8d70-bec392a001e5_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_48a3acec-468e-41a5-8d70-bec392a001e5" xlink:to="loc_srt_RangeMember_48a3acec-468e-41a5-8d70-bec392a001e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fcf0dfd4-e755-4a65-ad90-15b67a34bae2" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_48a3acec-468e-41a5-8d70-bec392a001e5" xlink:to="loc_srt_RangeMember_fcf0dfd4-e755-4a65-ad90-15b67a34bae2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_8703cb06-03e9-4fc3-bb3e-42d297e7ca77" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fcf0dfd4-e755-4a65-ad90-15b67a34bae2" xlink:to="loc_srt_MaximumMember_8703cb06-03e9-4fc3-bb3e-42d297e7ca77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_bc5e4862-8f30-4018-afc7-d18a53d6d220" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_56383747-bf91-42c8-925a-98b95e9517f0" xlink:to="loc_us-gaap_StatementClassOfStockAxis_bc5e4862-8f30-4018-afc7-d18a53d6d220" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_bc5e4862-8f30-4018-afc7-d18a53d6d220_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_bc5e4862-8f30-4018-afc7-d18a53d6d220" xlink:to="loc_us-gaap_ClassOfStockDomain_bc5e4862-8f30-4018-afc7-d18a53d6d220_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_5616c414-ff47-409d-b229-7cba8ec2a14f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_bc5e4862-8f30-4018-afc7-d18a53d6d220" xlink:to="loc_us-gaap_ClassOfStockDomain_5616c414-ff47-409d-b229-7cba8ec2a14f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_430170d3-d9ba-49e2-9104-3c84553ef3fa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_5616c414-ff47-409d-b229-7cba8ec2a14f" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_430170d3-d9ba-49e2-9104-3c84553ef3fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_a72e43d0-030d-40d7-b744-41c07e9ef4b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_5616c414-ff47-409d-b229-7cba8ec2a14f" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_a72e43d0-030d-40d7-b744-41c07e9ef4b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesEPreferredStockMember_d9179067-a015-4730-9a87-d3cbef6d5710" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesEPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_5616c414-ff47-409d-b229-7cba8ec2a14f" xlink:to="loc_us-gaap_SeriesEPreferredStockMember_d9179067-a015-4730-9a87-d3cbef6d5710" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_SeriesEConvertiblePreferredStockMember_e048e862-ab4d-429c-a95e-a60f6f3c4e58" xlink:href="glow-20221231.xsd#glow_SeriesEConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_5616c414-ff47-409d-b229-7cba8ec2a14f" xlink:to="loc_glow_SeriesEConvertiblePreferredStockMember_e048e862-ab4d-429c-a95e-a60f6f3c4e58" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3255fecd-2482-4e1b-922b-2fc6c2109145" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_56383747-bf91-42c8-925a-98b95e9517f0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3255fecd-2482-4e1b-922b-2fc6c2109145" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_3255fecd-2482-4e1b-922b-2fc6c2109145_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3255fecd-2482-4e1b-922b-2fc6c2109145" xlink:to="loc_us-gaap_EquityComponentDomain_3255fecd-2482-4e1b-922b-2fc6c2109145_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d1d0c600-4430-4184-9814-263f853da30d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3255fecd-2482-4e1b-922b-2fc6c2109145" xlink:to="loc_us-gaap_EquityComponentDomain_d1d0c600-4430-4184-9814-263f853da30d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_58848308-1837-4a6c-93f3-1f5afcd5930e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_d1d0c600-4430-4184-9814-263f853da30d" xlink:to="loc_us-gaap_CommonStockMember_58848308-1837-4a6c-93f3-1f5afcd5930e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_6fe03fce-c545-445d-8b97-df0a9b687bd2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_d1d0c600-4430-4184-9814-263f853da30d" xlink:to="loc_us-gaap_PreferredStockMember_6fe03fce-c545-445d-8b97-df0a9b687bd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_f80c6bb2-b1b7-4b66-8aa3-a08f92596421" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_56383747-bf91-42c8-925a-98b95e9517f0" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_f80c6bb2-b1b7-4b66-8aa3-a08f92596421" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_f80c6bb2-b1b7-4b66-8aa3-a08f92596421_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_f80c6bb2-b1b7-4b66-8aa3-a08f92596421" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_f80c6bb2-b1b7-4b66-8aa3-a08f92596421_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_0b6b8bd8-9c03-4368-9022-88070c9d1f76" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_f80c6bb2-b1b7-4b66-8aa3-a08f92596421" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_0b6b8bd8-9c03-4368-9022-88070c9d1f76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_68cab2b3-4950-4431-9716-d3c00b31d9b1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_0b6b8bd8-9c03-4368-9022-88070c9d1f76" xlink:to="loc_us-gaap_SubsequentEventMember_68cab2b3-4950-4431-9716-d3c00b31d9b1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/StockBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#StockBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/StockBasedCompensationNarrativeDetails" xlink:type="extended" id="id87fa2230d054f3fba5e2da8fddc1f24_StockBasedCompensationNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_5c03247a-eb0b-42dd-b370-b907458725f4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_5c03247a-eb0b-42dd-b370-b907458725f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_11d173a7-8b27-47d2-8ece-746c940ed2c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_11d173a7-8b27-47d2-8ece-746c940ed2c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_b17c0f0d-c527-4402-8adc-4babc0d4ac55" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_b17c0f0d-c527-4402-8adc-4babc0d4ac55" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_e5e15373-68d7-4c60-8f2e-895345c8414f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_e5e15373-68d7-4c60-8f2e-895345c8414f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_3754b392-4ca7-4a6b-a8d6-154d5aa3553a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_3754b392-4ca7-4a6b-a8d6-154d5aa3553a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_1215fdca-df74-4792-9762-76160c6fa47b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_1215fdca-df74-4792-9762-76160c6fa47b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_35b1716e-ad26-4920-9bfd-b4530a5b2bac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_35b1716e-ad26-4920-9bfd-b4530a5b2bac" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_5b7f7081-2c0b-4bda-9579-7c25f62afb51" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_5b7f7081-2c0b-4bda-9579-7c25f62afb51" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_35ab8cc4-4f4a-44b3-8b38-76dd16460fcd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_35ab8cc4-4f4a-44b3-8b38-76dd16460fcd" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_d80e771b-a2bf-4279-b6b2-e72eed47ebf5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_d80e771b-a2bf-4279-b6b2-e72eed47ebf5" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ShareBasedPaymentArrangementExpenseGross_90630ecb-1a3b-4e9a-a404-ca90a883fca7" xlink:href="glow-20221231.xsd#glow_ShareBasedPaymentArrangementExpenseGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_glow_ShareBasedPaymentArrangementExpenseGross_90630ecb-1a3b-4e9a-a404-ca90a883fca7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_7a37eb7b-b54d-4479-b77a-473432d3316b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationForfeited_7a37eb7b-b54d-4479-b77a-473432d3316b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_076e1060-05e9-42b1-aee2-21d5e93ed662" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_076e1060-05e9-42b1-aee2-21d5e93ed662" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_52841ae4-1444-4563-b301-065557ee0635" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_52841ae4-1444-4563-b301-065557ee0635" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_407299b8-8006-4a85-8800-1623fc80d481" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_407299b8-8006-4a85-8800-1623fc80d481" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_6e1fb06a-0840-415d-826e-5084c26b98a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_6e1fb06a-0840-415d-826e-5084c26b98a7" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_232d273a-0e86-43aa-a7ef-b0cd90a221fa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_232d273a-0e86-43aa-a7ef-b0cd90a221fa" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_5beaad39-eea5-4df8-8632-6958e7bb761d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_5beaad39-eea5-4df8-8632-6958e7bb761d" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueInPeriod_caabd6a5-85e2-4461-ade0-59adea1dd6c9" xlink:href="glow-20221231.xsd#glow_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_glow_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueInPeriod_caabd6a5-85e2-4461-ade0-59adea1dd6c9" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_58cddac9-6fe7-4bd0-b5fd-321435b5b6cb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_58cddac9-6fe7-4bd0-b5fd-321435b5b6cb" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodRemainOutstanding_5bd98fea-b3dd-484c-ac62-6432fcbfef4e" xlink:href="glow-20221231.xsd#glow_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodRemainOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_glow_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodRemainOutstanding_5bd98fea-b3dd-484c-ac62-6432fcbfef4e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_c3dc98a9-0da4-4427-8952-b321602ed652" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_c3dc98a9-0da4-4427-8952-b321602ed652" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1bad2035-930f-4cf8-a773-204a608540f2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_1bad2035-930f-4cf8-a773-204a608540f2" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_80c6c8ef-1f75-48b6-8f00-4fca4d451b6a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_a62f1caf-27d1-4152-b1fb-8e7cd549bced" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_PlanNameAxis_a62f1caf-27d1-4152-b1fb-8e7cd549bced" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_a62f1caf-27d1-4152-b1fb-8e7cd549bced_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_a62f1caf-27d1-4152-b1fb-8e7cd549bced" xlink:to="loc_us-gaap_PlanNameDomain_a62f1caf-27d1-4152-b1fb-8e7cd549bced_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_45b94cd4-6bfe-405d-8bb6-c59178d74d30" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_a62f1caf-27d1-4152-b1fb-8e7cd549bced" xlink:to="loc_us-gaap_PlanNameDomain_45b94cd4-6bfe-405d-8bb6-c59178d74d30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_A2019EquityIncentivePlanMember_e78e6e0e-36f7-4a89-a4c2-de339a3540bc" xlink:href="glow-20221231.xsd#glow_A2019EquityIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_45b94cd4-6bfe-405d-8bb6-c59178d74d30" xlink:to="loc_glow_A2019EquityIncentivePlanMember_e78e6e0e-36f7-4a89-a4c2-de339a3540bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_af10d034-a866-4bb8-9353-51c96b5c9a57" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_AwardTypeAxis_af10d034-a866-4bb8-9353-51c96b5c9a57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_af10d034-a866-4bb8-9353-51c96b5c9a57_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_af10d034-a866-4bb8-9353-51c96b5c9a57" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_af10d034-a866-4bb8-9353-51c96b5c9a57_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f1a884bd-3c41-4c8a-91b7-cf70a0872a2c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_af10d034-a866-4bb8-9353-51c96b5c9a57" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f1a884bd-3c41-4c8a-91b7-cf70a0872a2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_97ab07ab-0798-48ea-9aa8-e8be2eedf63a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f1a884bd-3c41-4c8a-91b7-cf70a0872a2c" xlink:to="loc_us-gaap_EmployeeStockOptionMember_97ab07ab-0798-48ea-9aa8-e8be2eedf63a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_18428aab-4e99-4a6d-8079-bb5099ac129c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f1a884bd-3c41-4c8a-91b7-cf70a0872a2c" xlink:to="loc_us-gaap_RestrictedStockMember_18428aab-4e99-4a6d-8079-bb5099ac129c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_fd311b94-8610-48db-9303-e86e66652bb5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f1a884bd-3c41-4c8a-91b7-cf70a0872a2c" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_fd311b94-8610-48db-9303-e86e66652bb5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusAxis_931d52ce-d335-49bb-94ce-3929dadf1d39" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GranteeStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_GranteeStatusAxis_931d52ce-d335-49bb-94ce-3929dadf1d39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_931d52ce-d335-49bb-94ce-3929dadf1d39_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GranteeStatusAxis_931d52ce-d335-49bb-94ce-3929dadf1d39" xlink:to="loc_us-gaap_GranteeStatusDomain_931d52ce-d335-49bb-94ce-3929dadf1d39_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_c7c9493a-96a2-4755-9da7-326fb1f4b5c5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GranteeStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GranteeStatusAxis_931d52ce-d335-49bb-94ce-3929dadf1d39" xlink:to="loc_us-gaap_GranteeStatusDomain_c7c9493a-96a2-4755-9da7-326fb1f4b5c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_209afac8-1712-4d63-916f-bafd503f418c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedPaymentArrangementEmployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_c7c9493a-96a2-4755-9da7-326fb1f4b5c5" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementEmployeeMember_209afac8-1712-4d63-916f-bafd503f418c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_70f6418b-1e3a-4167-a26b-97fb123b50ba" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedPaymentArrangementNonemployeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_c7c9493a-96a2-4755-9da7-326fb1f4b5c5" xlink:to="loc_us-gaap_ShareBasedPaymentArrangementNonemployeeMember_70f6418b-1e3a-4167-a26b-97fb123b50ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_5219f819-7f5f-4012-bc17-3878f2f9b3b2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_StatementClassOfStockAxis_5219f819-7f5f-4012-bc17-3878f2f9b3b2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_5219f819-7f5f-4012-bc17-3878f2f9b3b2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_5219f819-7f5f-4012-bc17-3878f2f9b3b2" xlink:to="loc_us-gaap_ClassOfStockDomain_5219f819-7f5f-4012-bc17-3878f2f9b3b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3f46df4d-8ecb-473e-bd44-764981ef2593" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_5219f819-7f5f-4012-bc17-3878f2f9b3b2" xlink:to="loc_us-gaap_ClassOfStockDomain_3f46df4d-8ecb-473e-bd44-764981ef2593" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_cc8fefbf-8ca9-469e-8016-b9f564e54c86" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_3f46df4d-8ecb-473e-bd44-764981ef2593" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_cc8fefbf-8ca9-469e-8016-b9f564e54c86" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_66925fbf-8c81-4a55-bb57-701f0d40eb04" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_VestingAxis_66925fbf-8c81-4a55-bb57-701f0d40eb04" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_66925fbf-8c81-4a55-bb57-701f0d40eb04_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_66925fbf-8c81-4a55-bb57-701f0d40eb04" xlink:to="loc_us-gaap_VestingDomain_66925fbf-8c81-4a55-bb57-701f0d40eb04_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_202b7bf2-5a4f-449a-acd1-e84036bbc7eb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_66925fbf-8c81-4a55-bb57-701f0d40eb04" xlink:to="loc_us-gaap_VestingDomain_202b7bf2-5a4f-449a-acd1-e84036bbc7eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_688467fc-bb28-4270-93f2-b7256d47d80c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_202b7bf2-5a4f-449a-acd1-e84036bbc7eb" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_688467fc-bb28-4270-93f2-b7256d47d80c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_c8414032-c292-457e-8921-2693dffa4cc0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_202b7bf2-5a4f-449a-acd1-e84036bbc7eb" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_c8414032-c292-457e-8921-2693dffa4cc0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_1140531a-7f82-45f8-a71c-0bf4311e5481" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_202b7bf2-5a4f-449a-acd1-e84036bbc7eb" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_1140531a-7f82-45f8-a71c-0bf4311e5481" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_d134f8bb-aad4-4e29-b437-ecc8d9af9339" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_d134f8bb-aad4-4e29-b437-ecc8d9af9339" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_d134f8bb-aad4-4e29-b437-ecc8d9af9339_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_d134f8bb-aad4-4e29-b437-ecc8d9af9339" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_d134f8bb-aad4-4e29-b437-ecc8d9af9339_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_65eabc6c-b37c-470e-91a0-75ae60e0cc36" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_d134f8bb-aad4-4e29-b437-ecc8d9af9339" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_65eabc6c-b37c-470e-91a0-75ae60e0cc36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_6b8f7779-0790-4d8c-8556-06e87e1840e2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_65eabc6c-b37c-470e-91a0-75ae60e0cc36" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_6b8f7779-0790-4d8c-8556-06e87e1840e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_ee45b1e7-93f5-4bfb-a435-4988eb31a943" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_65eabc6c-b37c-470e-91a0-75ae60e0cc36" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_ee45b1e7-93f5-4bfb-a435-4988eb31a943" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_9a3837a7-a2e0-411c-8810-0da12a0ca033" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_9d86794e-144f-4592-b1dd-238c54adf736" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_9a3837a7-a2e0-411c-8810-0da12a0ca033" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_9a3837a7-a2e0-411c-8810-0da12a0ca033_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_9a3837a7-a2e0-411c-8810-0da12a0ca033" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_9a3837a7-a2e0-411c-8810-0da12a0ca033_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_9cbc4d9e-9889-40d0-99c5-e84c15984a9a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_9a3837a7-a2e0-411c-8810-0da12a0ca033" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_9cbc4d9e-9889-40d0-99c5-e84c15984a9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_555ca6de-06b3-43c6-9ddd-405760ee7bb7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_9cbc4d9e-9889-40d0-99c5-e84c15984a9a" xlink:to="loc_us-gaap_SubsequentEventMember_555ca6de-06b3-43c6-9ddd-405760ee7bb7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/StockBasedCompensationExercisePriceRangeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#StockBasedCompensationExercisePriceRangeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/StockBasedCompensationExercisePriceRangeDetails" xlink:type="extended" id="i23e01c04968a4253abf8ddd18c7df9de_StockBasedCompensationExercisePriceRangeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_28aa3341-ce62-4629-b9b1-0c7469373ced" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_28aa3341-ce62-4629-b9b1-0c7469373ced" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_8427a9b8-965c-4676-b37f-474bbbc389a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_8427a9b8-965c-4676-b37f-474bbbc389a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_ef7915f6-cb10-4bca-aa60-d99b3c33978a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_ef7915f6-cb10-4bca-aa60-d99b3c33978a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_1ef574db-b5a8-400b-93e8-707a4f5aa421" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_1ef574db-b5a8-400b-93e8-707a4f5aa421" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_71e92d74-0b4d-43c3-b85b-634ff38197e0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_71e92d74-0b4d-43c3-b85b-634ff38197e0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_7fe0bdd9-5c9c-4ef0-8085-3454a928fcea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_7fe0bdd9-5c9c-4ef0-8085-3454a928fcea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_93d1266d-3978-4b3e-89e9-e8cd8660da4d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_93d1266d-3978-4b3e-89e9-e8cd8660da4d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_12bf13dc-f714-44bd-813c-c8f3c0aa5356" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_bb0f1005-e4c0-45a3-accc-3d396f622b27" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_12bf13dc-f714-44bd-813c-c8f3c0aa5356" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_b048cdf7-1a15-44c1-8634-47adb74e6ba1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_12bf13dc-f714-44bd-813c-c8f3c0aa5356" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_b048cdf7-1a15-44c1-8634-47adb74e6ba1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_b048cdf7-1a15-44c1-8634-47adb74e6ba1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_b048cdf7-1a15-44c1-8634-47adb74e6ba1" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_b048cdf7-1a15-44c1-8634-47adb74e6ba1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_749846c3-7787-4c39-add9-d386726ab6e3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_b048cdf7-1a15-44c1-8634-47adb74e6ba1" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_749846c3-7787-4c39-add9-d386726ab6e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ExercisePriceRange1Member_0ae19aba-42bc-4878-b078-c480fbabfadd" xlink:href="glow-20221231.xsd#glow_ExercisePriceRange1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_749846c3-7787-4c39-add9-d386726ab6e3" xlink:to="loc_glow_ExercisePriceRange1Member_0ae19aba-42bc-4878-b078-c480fbabfadd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ExercisePriceRange2Member_59d11fa8-5474-4613-bdd9-0fb18d32642f" xlink:href="glow-20221231.xsd#glow_ExercisePriceRange2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_749846c3-7787-4c39-add9-d386726ab6e3" xlink:to="loc_glow_ExercisePriceRange2Member_59d11fa8-5474-4613-bdd9-0fb18d32642f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ExercisePriceRange3Member_7dd2c4c6-8518-41aa-914d-0ade9e7b0fb0" xlink:href="glow-20221231.xsd#glow_ExercisePriceRange3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_749846c3-7787-4c39-add9-d386726ab6e3" xlink:to="loc_glow_ExercisePriceRange3Member_7dd2c4c6-8518-41aa-914d-0ade9e7b0fb0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/StockBasedCompensationStockCompensationExpenseRestrictedStockDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#StockBasedCompensationStockCompensationExpenseRestrictedStockDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/StockBasedCompensationStockCompensationExpenseRestrictedStockDetails" xlink:type="extended" id="i74df549f75484ed7be8b9545489bfb6f_StockBasedCompensationStockCompensationExpenseRestrictedStockDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_17202101-d6a4-46ba-bf97-c9cc0ee77e97" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_750bfa0f-68ee-4469-9e5d-85174361f9c0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_17202101-d6a4-46ba-bf97-c9cc0ee77e97" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_750bfa0f-68ee-4469-9e5d-85174361f9c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_698e7f9a-860c-4c24-a6de-ff328a96e16c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_17202101-d6a4-46ba-bf97-c9cc0ee77e97" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_698e7f9a-860c-4c24-a6de-ff328a96e16c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_e4d92a0b-9eeb-4949-90ed-c513feffdba8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_698e7f9a-860c-4c24-a6de-ff328a96e16c" xlink:to="loc_us-gaap_AwardTypeAxis_e4d92a0b-9eeb-4949-90ed-c513feffdba8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e4d92a0b-9eeb-4949-90ed-c513feffdba8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_e4d92a0b-9eeb-4949-90ed-c513feffdba8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e4d92a0b-9eeb-4949-90ed-c513feffdba8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ef463af8-85df-4b24-acec-fa9b0f11e1d5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_e4d92a0b-9eeb-4949-90ed-c513feffdba8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ef463af8-85df-4b24-acec-fa9b0f11e1d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_bd19ecf6-2a50-4cb4-9297-29d78fe749a5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ef463af8-85df-4b24-acec-fa9b0f11e1d5" xlink:to="loc_us-gaap_RestrictedStockMember_bd19ecf6-2a50-4cb4-9297-29d78fe749a5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_6e712f8b-46a1-4759-950e-c5d42111175d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_698e7f9a-860c-4c24-a6de-ff328a96e16c" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_6e712f8b-46a1-4759-950e-c5d42111175d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_6e712f8b-46a1-4759-950e-c5d42111175d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_6e712f8b-46a1-4759-950e-c5d42111175d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_6e712f8b-46a1-4759-950e-c5d42111175d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_26a95994-8ba5-4116-ab21-4f0d8971d7df" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_6e712f8b-46a1-4759-950e-c5d42111175d" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_26a95994-8ba5-4116-ab21-4f0d8971d7df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_384e6c33-778d-45b4-b69e-2f47931f5718" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_26a95994-8ba5-4116-ab21-4f0d8971d7df" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_384e6c33-778d-45b4-b69e-2f47931f5718" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_db9b5766-91ab-49db-bf83-9fc2320fdfe1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_26a95994-8ba5-4116-ab21-4f0d8971d7df" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_db9b5766-91ab-49db-bf83-9fc2320fdfe1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_444d73f2-27d8-4076-b1d3-e43e95d8f488" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_698e7f9a-860c-4c24-a6de-ff328a96e16c" xlink:to="loc_us-gaap_StatementClassOfStockAxis_444d73f2-27d8-4076-b1d3-e43e95d8f488" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_444d73f2-27d8-4076-b1d3-e43e95d8f488_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_444d73f2-27d8-4076-b1d3-e43e95d8f488" xlink:to="loc_us-gaap_ClassOfStockDomain_444d73f2-27d8-4076-b1d3-e43e95d8f488_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_011d0f0b-0be0-44d2-b80a-09a5a5595b9c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_444d73f2-27d8-4076-b1d3-e43e95d8f488" xlink:to="loc_us-gaap_ClassOfStockDomain_011d0f0b-0be0-44d2-b80a-09a5a5595b9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesDPreferredStockMember_d807032e-e98d-4c46-ab2b-4f0fa651e599" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeriesDPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_011d0f0b-0be0-44d2-b80a-09a5a5595b9c" xlink:to="loc_us-gaap_SeriesDPreferredStockMember_d807032e-e98d-4c46-ab2b-4f0fa651e599" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/NetLossPerShareNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#NetLossPerShareNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/NetLossPerShareNarrativeDetails" xlink:type="extended" id="i16fc414029614359b8b468f54da71ce0_NetLossPerShareNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8c51c0be-d180-4bd3-b1e3-0f073d6cc218" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_162141ac-840f-429d-bd8e-e0889db84847" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8c51c0be-d180-4bd3-b1e3-0f073d6cc218" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_162141ac-840f-429d-bd8e-e0889db84847" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_b5e1cc93-550e-4e99-984c-305c69660520" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8c51c0be-d180-4bd3-b1e3-0f073d6cc218" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_b5e1cc93-550e-4e99-984c-305c69660520" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodRemainOutstanding_7de5830f-5e39-4260-a06a-7d786ce99292" xlink:href="glow-20221231.xsd#glow_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodRemainOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8c51c0be-d180-4bd3-b1e3-0f073d6cc218" xlink:to="loc_glow_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsVestedinPeriodRemainOutstanding_7de5830f-5e39-4260-a06a-7d786ce99292" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fda8d9b7-8ce9-44ed-a5da-1f575027a784" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_8c51c0be-d180-4bd3-b1e3-0f073d6cc218" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fda8d9b7-8ce9-44ed-a5da-1f575027a784" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_31f6cd73-31a3-40fb-b7fe-6b2528ffb2e3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fda8d9b7-8ce9-44ed-a5da-1f575027a784" xlink:to="loc_us-gaap_AwardTypeAxis_31f6cd73-31a3-40fb-b7fe-6b2528ffb2e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_31f6cd73-31a3-40fb-b7fe-6b2528ffb2e3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_31f6cd73-31a3-40fb-b7fe-6b2528ffb2e3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_31f6cd73-31a3-40fb-b7fe-6b2528ffb2e3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f7ff39f9-17ba-4b0b-9027-8220e690cc03" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_31f6cd73-31a3-40fb-b7fe-6b2528ffb2e3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f7ff39f9-17ba-4b0b-9027-8220e690cc03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_66d9c00f-cc85-4913-acce-17de187ebcda" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_f7ff39f9-17ba-4b0b-9027-8220e690cc03" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_66d9c00f-cc85-4913-acce-17de187ebcda" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_591afa50-70af-4b1d-8712-0a41acedb8b5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fda8d9b7-8ce9-44ed-a5da-1f575027a784" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_591afa50-70af-4b1d-8712-0a41acedb8b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_591afa50-70af-4b1d-8712-0a41acedb8b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_591afa50-70af-4b1d-8712-0a41acedb8b5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_591afa50-70af-4b1d-8712-0a41acedb8b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_a683d530-acb0-4f11-ba8f-92495ce72855" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_591afa50-70af-4b1d-8712-0a41acedb8b5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_a683d530-acb0-4f11-ba8f-92495ce72855" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_7d140f97-04dd-4c01-a425-cc6477b39ac5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_a683d530-acb0-4f11-ba8f-92495ce72855" xlink:to="loc_us-gaap_SubsequentEventMember_7d140f97-04dd-4c01-a425-cc6477b39ac5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/NetLossPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#NetLossPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/NetLossPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails" xlink:type="extended" id="ie75216cc0e2849559a4a69af0658d7db_NetLossPerShareScheduleofAntidilutiveSecuritiesExcludedfromComputationofEarningsPerShareDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_2a6f427a-8206-4d5a-8f4c-1c958f43cd10" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_bd45e088-d2e6-428d-be83-cdf2ae928f6d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_2a6f427a-8206-4d5a-8f4c-1c958f43cd10" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_bd45e088-d2e6-428d-be83-cdf2ae928f6d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_f2c7ef57-5251-4359-9d3d-8e9418fcefee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_2a6f427a-8206-4d5a-8f4c-1c958f43cd10" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_f2c7ef57-5251-4359-9d3d-8e9418fcefee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0859fb3e-0c5d-477d-826c-d84aca0fddb8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_f2c7ef57-5251-4359-9d3d-8e9418fcefee" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0859fb3e-0c5d-477d-826c-d84aca0fddb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_0859fb3e-0c5d-477d-826c-d84aca0fddb8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0859fb3e-0c5d-477d-826c-d84aca0fddb8" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_0859fb3e-0c5d-477d-826c-d84aca0fddb8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_49db3000-dd2b-4bff-a65a-fe350bc2a714" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_0859fb3e-0c5d-477d-826c-d84aca0fddb8" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_49db3000-dd2b-4bff-a65a-fe350bc2a714" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_e875da73-88b5-4e01-ae67-ceb95aa2ad57" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_49db3000-dd2b-4bff-a65a-fe350bc2a714" xlink:to="loc_us-gaap_EmployeeStockOptionMember_e875da73-88b5-4e01-ae67-ceb95aa2ad57" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_32d9e2ba-6767-4e26-b581-c8889c51e4c8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_49db3000-dd2b-4bff-a65a-fe350bc2a714" xlink:to="loc_us-gaap_WarrantMember_32d9e2ba-6767-4e26-b581-c8889c51e4c8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/SegmentReportingDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#SegmentReportingDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/SegmentReportingDetails" xlink:type="extended" id="i875c06c06ba344a4b46e71890629b3ed_SegmentReportingDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_044e9695-f030-4fad-b302-ad093b5dfdf5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_NumberOfOperatingSegments_044e9695-f030-4fad-b302-ad093b5dfdf5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_20e8c698-f029-4000-a2de-c0eff7590604" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_20e8c698-f029-4000-a2de-c0eff7590604" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_45d6955d-0926-4a65-b405-9286f58b1292" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_45d6955d-0926-4a65-b405-9286f58b1292" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_86635454-cdd9-4d4e-9a6e-6753a3ab552a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_GrossProfit_86635454-cdd9-4d4e-9a6e-6753a3ab552a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_GrossProfitPercentage_3512f807-8c0f-45db-a88e-ca80385222d6" xlink:href="glow-20221231.xsd#glow_GrossProfitPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_glow_GrossProfitPercentage_3512f807-8c0f-45db-a88e-ca80385222d6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_917fe464-b0e5-45c9-8cad-56fe3af7921b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_CostsAndExpenses_917fe464-b0e5-45c9-8cad-56fe3af7921b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_575876eb-cdf2-451f-815b-d8f34c0f6ed7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_OperatingIncomeLoss_575876eb-cdf2-451f-815b-d8f34c0f6ed7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_427ab623-031b-4285-8df7-0529440e7fc3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_427ab623-031b-4285-8df7-0529440e7fc3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_5d030840-ed7e-4a94-944f-f09cf97cc130" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_5d030840-ed7e-4a94-944f-f09cf97cc130" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_23407bbf-0280-4208-be0d-51da62182284" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_23407bbf-0280-4208-be0d-51da62182284" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_03cb8601-dc34-42c2-b656-ac13f56fadb3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_NetIncomeLoss_03cb8601-dc34-42c2-b656-ac13f56fadb3" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_962fc316-58a0-4c99-b6f0-2788bc673c62" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_Assets_962fc316-58a0-4c99-b6f0-2788bc673c62" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_58b8c842-25a6-4211-9281-634bf506bbae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_8c141c90-ead6-4459-90af-dec301728dd0" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_58b8c842-25a6-4211-9281-634bf506bbae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_da6af9c3-55da-4413-a760-49361666fd60" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_58b8c842-25a6-4211-9281-634bf506bbae" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_da6af9c3-55da-4413-a760-49361666fd60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_da6af9c3-55da-4413-a760-49361666fd60_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_da6af9c3-55da-4413-a760-49361666fd60" xlink:to="loc_us-gaap_SegmentDomain_da6af9c3-55da-4413-a760-49361666fd60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_2ef08093-ccbf-49ae-a28d-5a25bfc13e10" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_da6af9c3-55da-4413-a760-49361666fd60" xlink:to="loc_us-gaap_SegmentDomain_2ef08093-ccbf-49ae-a28d-5a25bfc13e10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ManagedServicesMember_d6d17a1c-01c9-4c31-8b81-84eda13abf3c" xlink:href="glow-20221231.xsd#glow_ManagedServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2ef08093-ccbf-49ae-a28d-5a25bfc13e10" xlink:to="loc_glow_ManagedServicesMember_d6d17a1c-01c9-4c31-8b81-84eda13abf3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CollaborationProductsMember_fe08bf6b-95f3-479d-882d-470a22b59e06" xlink:href="glow-20221231.xsd#glow_CollaborationProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2ef08093-ccbf-49ae-a28d-5a25bfc13e10" xlink:to="loc_glow_CollaborationProductsMember_fe08bf6b-95f3-479d-882d-470a22b59e06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_54c1616b-3ad2-4e57-b4f7-ff9d2141decf" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_58b8c842-25a6-4211-9281-634bf506bbae" xlink:to="loc_srt_ConsolidationItemsAxis_54c1616b-3ad2-4e57-b4f7-ff9d2141decf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_54c1616b-3ad2-4e57-b4f7-ff9d2141decf_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_54c1616b-3ad2-4e57-b4f7-ff9d2141decf" xlink:to="loc_srt_ConsolidationItemsDomain_54c1616b-3ad2-4e57-b4f7-ff9d2141decf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_e3df66de-e73d-44d8-9b24-dcd2ca759855" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_54c1616b-3ad2-4e57-b4f7-ff9d2141decf" xlink:to="loc_srt_ConsolidationItemsDomain_e3df66de-e73d-44d8-9b24-dcd2ca759855" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_5f71be8c-b29c-4d9a-b317-8de20556315b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_e3df66de-e73d-44d8-9b24-dcd2ca759855" xlink:to="loc_us-gaap_OperatingSegmentsMember_5f71be8c-b29c-4d9a-b317-8de20556315b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_2084c7e9-f8ff-47b8-ba64-9feb1dae9930" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_e3df66de-e73d-44d8-9b24-dcd2ca759855" xlink:to="loc_us-gaap_CorporateNonSegmentMember_2084c7e9-f8ff-47b8-ba64-9feb1dae9930" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsAxis_0e707fb4-8555-460f-b4a1-8ad9e8c91dc5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_58b8c842-25a6-4211-9281-634bf506bbae" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsAxis_0e707fb4-8555-460f-b4a1-8ad9e8c91dc5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsDomain_0e707fb4-8555-460f-b4a1-8ad9e8c91dc5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsAxis_0e707fb4-8555-460f-b4a1-8ad9e8c91dc5" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsDomain_0e707fb4-8555-460f-b4a1-8ad9e8c91dc5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsConsolidationItemsDomain_c55da947-1a58-4b5d-8d74-56dd589107d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsAxis_0e707fb4-8555-460f-b4a1-8ad9e8c91dc5" xlink:to="loc_us-gaap_SubsegmentsConsolidationItemsDomain_c55da947-1a58-4b5d-8d74-56dd589107d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_dc8fcf75-964a-434c-8cd0-3eb752958b9b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsDomain_c55da947-1a58-4b5d-8d74-56dd589107d2" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_dc8fcf75-964a-434c-8cd0-3eb752958b9b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_6e2023ea-b4bc-4821-af9b-60e4697a41bc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsConsolidationItemsDomain_c55da947-1a58-4b5d-8d74-56dd589107d2" xlink:to="loc_us-gaap_CorporateNonSegmentMember_6e2023ea-b4bc-4821-af9b-60e4697a41bc" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/SegmentReportingDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#SegmentReportingDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/SegmentReportingDisaggregationofRevenueDetails" xlink:type="extended" id="i8957c6ab33ab41a88f8e7e651998588c_SegmentReportingDisaggregationofRevenueDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_e3dbd80f-c8cd-489a-aa7f-0a65b4ecff14" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyExchangeRateRemeasurement1_c16e2e58-9aec-428f-8cd4-39ee78cb1515" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignCurrencyExchangeRateRemeasurement1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_e3dbd80f-c8cd-489a-aa7f-0a65b4ecff14" xlink:to="loc_us-gaap_ForeignCurrencyExchangeRateRemeasurement1_c16e2e58-9aec-428f-8cd4-39ee78cb1515" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_50d637a2-306c-40f2-9b5a-466c288216bf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_e3dbd80f-c8cd-489a-aa7f-0a65b4ecff14" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_50d637a2-306c-40f2-9b5a-466c288216bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_519a7a3f-ec43-422d-9ef3-42f08fdf2d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_e3dbd80f-c8cd-489a-aa7f-0a65b4ecff14" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_519a7a3f-ec43-422d-9ef3-42f08fdf2d7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_e3dbd80f-c8cd-489a-aa7f-0a65b4ecff14" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_8248389b-7120-4a3e-bfe8-04707c427cb5" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:to="loc_srt_StatementGeographicalAxis_8248389b-7120-4a3e-bfe8-04707c427cb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_8248389b-7120-4a3e-bfe8-04707c427cb5_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_8248389b-7120-4a3e-bfe8-04707c427cb5" xlink:to="loc_srt_SegmentGeographicalDomain_8248389b-7120-4a3e-bfe8-04707c427cb5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_e4d113f1-f1ff-4109-b817-733dc684daab" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_8248389b-7120-4a3e-bfe8-04707c427cb5" xlink:to="loc_srt_SegmentGeographicalDomain_e4d113f1-f1ff-4109-b817-733dc684daab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_78cef37f-2b0a-4719-a2d4-95a4ecd771c4" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_e4d113f1-f1ff-4109-b817-733dc684daab" xlink:to="loc_country_US_78cef37f-2b0a-4719-a2d4-95a4ecd771c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_17005f6b-a4b8-4004-85bd-ebb12aaf9be7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_e4d113f1-f1ff-4109-b817-733dc684daab" xlink:to="loc_us-gaap_NonUsMember_17005f6b-a4b8-4004-85bd-ebb12aaf9be7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_23fbeafe-f957-4dec-92e0-3a9cce8a8a91" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_23fbeafe-f957-4dec-92e0-3a9cce8a8a91" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_23fbeafe-f957-4dec-92e0-3a9cce8a8a91_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_23fbeafe-f957-4dec-92e0-3a9cce8a8a91" xlink:to="loc_us-gaap_SegmentDomain_23fbeafe-f957-4dec-92e0-3a9cce8a8a91_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_eed6b143-7bbd-4168-847e-e9b247db536d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_23fbeafe-f957-4dec-92e0-3a9cce8a8a91" xlink:to="loc_us-gaap_SegmentDomain_eed6b143-7bbd-4168-847e-e9b247db536d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ManagedServicesMember_5d9c4864-5449-4967-ab76-dff6e7808a1d" xlink:href="glow-20221231.xsd#glow_ManagedServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_eed6b143-7bbd-4168-847e-e9b247db536d" xlink:to="loc_glow_ManagedServicesMember_5d9c4864-5449-4967-ab76-dff6e7808a1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CollaborationProductsMember_72320d0f-f6b6-4da7-924c-0f576b18d20d" xlink:href="glow-20221231.xsd#glow_CollaborationProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_eed6b143-7bbd-4168-847e-e9b247db536d" xlink:to="loc_glow_CollaborationProductsMember_72320d0f-f6b6-4da7-924c-0f576b18d20d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_f4e3c768-d1d5-49dd-b2f1-85b927c1565a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:to="loc_srt_ProductOrServiceAxis_f4e3c768-d1d5-49dd-b2f1-85b927c1565a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_f4e3c768-d1d5-49dd-b2f1-85b927c1565a_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_f4e3c768-d1d5-49dd-b2f1-85b927c1565a" xlink:to="loc_srt_ProductsAndServicesDomain_f4e3c768-d1d5-49dd-b2f1-85b927c1565a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_419a9b7a-8dfa-4905-8756-6352cbc6f4f8" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_f4e3c768-d1d5-49dd-b2f1-85b927c1565a" xlink:to="loc_srt_ProductsAndServicesDomain_419a9b7a-8dfa-4905-8756-6352cbc6f4f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_VideoCollaborationServiceMember_32809fbc-d0bd-4165-8943-d1dfc0c777b6" xlink:href="glow-20221231.xsd#glow_VideoCollaborationServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_419a9b7a-8dfa-4905-8756-6352cbc6f4f8" xlink:to="loc_glow_VideoCollaborationServiceMember_32809fbc-d0bd-4165-8943-d1dfc0c777b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_NetworkServicesMember_54ebc345-771d-4327-b7bd-8ff487dcc342" xlink:href="glow-20221231.xsd#glow_NetworkServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_419a9b7a-8dfa-4905-8756-6352cbc6f4f8" xlink:to="loc_glow_NetworkServicesMember_54ebc345-771d-4327-b7bd-8ff487dcc342" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ProfessionalAndOtherServicesMember_9ce27083-c46d-4a45-bd90-f95fde43a4c7" xlink:href="glow-20221231.xsd#glow_ProfessionalAndOtherServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_419a9b7a-8dfa-4905-8756-6352cbc6f4f8" xlink:to="loc_glow_ProfessionalAndOtherServicesMember_9ce27083-c46d-4a45-bd90-f95fde43a4c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicenseMember_f130d146-7d1b-4797-b8c0-f848391e9480" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LicenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_419a9b7a-8dfa-4905-8756-6352cbc6f4f8" xlink:to="loc_us-gaap_LicenseMember_f130d146-7d1b-4797-b8c0-f848391e9480" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56efc8fc-4186-4e58-a005-099812d9a3ed" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56efc8fc-4186-4e58-a005-099812d9a3ed" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_56efc8fc-4186-4e58-a005-099812d9a3ed_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56efc8fc-4186-4e58-a005-099812d9a3ed" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_56efc8fc-4186-4e58-a005-099812d9a3ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f722ff00-c20a-41c9-b9d6-e0182278d6e0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56efc8fc-4186-4e58-a005-099812d9a3ed" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f722ff00-c20a-41c9-b9d6-e0182278d6e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_e5baf252-e466-416c-90f1-8d7455d633fc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f722ff00-c20a-41c9-b9d6-e0182278d6e0" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_e5baf252-e466-416c-90f1-8d7455d633fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsTotalMember_39908f26-d159-4606-b005-2845d582dc9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsTotalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f722ff00-c20a-41c9-b9d6-e0182278d6e0" xlink:to="loc_us-gaap_AssetsTotalMember_39908f26-d159-4606-b005-2845d582dc9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_aa854fdb-7957-4e05-9238-a945b489b16c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_f54600ff-b230-4abd-b142-572b7d299e11" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_aa854fdb-7957-4e05-9238-a945b489b16c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_aa854fdb-7957-4e05-9238-a945b489b16c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_aa854fdb-7957-4e05-9238-a945b489b16c" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_aa854fdb-7957-4e05-9238-a945b489b16c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_b74a863b-36c0-49b1-927a-ddfba2da94e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_aa854fdb-7957-4e05-9238-a945b489b16c" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_b74a863b-36c0-49b1-927a-ddfba2da94e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductConcentrationRiskMember_ee96a0ea-4911-46bd-aa76-025dcb58a78b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_b74a863b-36c0-49b1-927a-ddfba2da94e5" xlink:to="loc_us-gaap_ProductConcentrationRiskMember_ee96a0ea-4911-46bd-aa76-025dcb58a78b" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/SegmentReportingConcentrationPercentageDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#SegmentReportingConcentrationPercentageDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/SegmentReportingConcentrationPercentageDetails" xlink:type="extended" id="iab27da4e3fdf40f0979bc506d730486f_SegmentReportingConcentrationPercentageDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_a9391935-c94c-4851-8224-62c48cbcb7ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_5d73deab-680c-477e-ba6d-55b0b9d8d986" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_a9391935-c94c-4851-8224-62c48cbcb7ca" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_5d73deab-680c-477e-ba6d-55b0b9d8d986" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_49edfe81-e0ad-4263-b66d-a1aacbeb988a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_a9391935-c94c-4851-8224-62c48cbcb7ca" xlink:to="loc_us-gaap_ConcentrationRiskTable_49edfe81-e0ad-4263-b66d-a1aacbeb988a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_e8a11a1f-3315-4dda-99f8-a8ef813f5298" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_49edfe81-e0ad-4263-b66d-a1aacbeb988a" xlink:to="loc_srt_MajorCustomersAxis_e8a11a1f-3315-4dda-99f8-a8ef813f5298" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_e8a11a1f-3315-4dda-99f8-a8ef813f5298_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_e8a11a1f-3315-4dda-99f8-a8ef813f5298" xlink:to="loc_srt_NameOfMajorCustomerDomain_e8a11a1f-3315-4dda-99f8-a8ef813f5298_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_99e65fa0-7865-48b1-8b32-88c0dacb20d2" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_e8a11a1f-3315-4dda-99f8-a8ef813f5298" xlink:to="loc_srt_NameOfMajorCustomerDomain_99e65fa0-7865-48b1-8b32-88c0dacb20d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CustomerNumberOneMember_2f03c327-f1b3-4409-aa5c-8eee0abdcb2c" xlink:href="glow-20221231.xsd#glow_CustomerNumberOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_99e65fa0-7865-48b1-8b32-88c0dacb20d2" xlink:to="loc_glow_CustomerNumberOneMember_2f03c327-f1b3-4409-aa5c-8eee0abdcb2c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CustomerNumberTwoMember_b14f330e-0646-4d8e-a3af-a1809455338f" xlink:href="glow-20221231.xsd#glow_CustomerNumberTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_99e65fa0-7865-48b1-8b32-88c0dacb20d2" xlink:to="loc_glow_CustomerNumberTwoMember_b14f330e-0646-4d8e-a3af-a1809455338f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CustomerNumberThreeMember_1aee8021-a4e1-4864-a761-fec632be5dfe" xlink:href="glow-20221231.xsd#glow_CustomerNumberThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_99e65fa0-7865-48b1-8b32-88c0dacb20d2" xlink:to="loc_glow_CustomerNumberThreeMember_1aee8021-a4e1-4864-a761-fec632be5dfe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CustomerNumberFourMember_5cd8f62e-84ef-4427-9e52-4189c7ea3c8d" xlink:href="glow-20221231.xsd#glow_CustomerNumberFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_99e65fa0-7865-48b1-8b32-88c0dacb20d2" xlink:to="loc_glow_CustomerNumberFourMember_5cd8f62e-84ef-4427-9e52-4189c7ea3c8d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_83433fc5-ab3e-4e4f-8275-e47e64e34e31" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_49edfe81-e0ad-4263-b66d-a1aacbeb988a" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_83433fc5-ab3e-4e4f-8275-e47e64e34e31" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_83433fc5-ab3e-4e4f-8275-e47e64e34e31_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_83433fc5-ab3e-4e4f-8275-e47e64e34e31" xlink:to="loc_us-gaap_SegmentDomain_83433fc5-ab3e-4e4f-8275-e47e64e34e31_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_bc3b0663-f520-48ba-8e4e-96f206599d7e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_83433fc5-ab3e-4e4f-8275-e47e64e34e31" xlink:to="loc_us-gaap_SegmentDomain_bc3b0663-f520-48ba-8e4e-96f206599d7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_ManagedServicesMember_3aa9e037-f571-4417-9951-d10a06d43d7e" xlink:href="glow-20221231.xsd#glow_ManagedServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_bc3b0663-f520-48ba-8e4e-96f206599d7e" xlink:to="loc_glow_ManagedServicesMember_3aa9e037-f571-4417-9951-d10a06d43d7e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CollaborationProductsMember_2a25fd6b-f193-4714-9506-d1a004c3b86c" xlink:href="glow-20221231.xsd#glow_CollaborationProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_bc3b0663-f520-48ba-8e4e-96f206599d7e" xlink:to="loc_glow_CollaborationProductsMember_2a25fd6b-f193-4714-9506-d1a004c3b86c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_27a76c5c-64ff-4b93-a17f-eaa5fbd90943" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_49edfe81-e0ad-4263-b66d-a1aacbeb988a" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_27a76c5c-64ff-4b93-a17f-eaa5fbd90943" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_27a76c5c-64ff-4b93-a17f-eaa5fbd90943_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_27a76c5c-64ff-4b93-a17f-eaa5fbd90943" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_27a76c5c-64ff-4b93-a17f-eaa5fbd90943_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_59612ea6-46c5-4e16-8b9c-179153b0eebe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_27a76c5c-64ff-4b93-a17f-eaa5fbd90943" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_59612ea6-46c5-4e16-8b9c-179153b0eebe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_7ff27abe-df4b-4d82-9943-014d82759a3b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_59612ea6-46c5-4e16-8b9c-179153b0eebe" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_7ff27abe-df4b-4d82-9943-014d82759a3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_ac84e9f6-2de2-48bd-80a4-e5865d20a200" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_59612ea6-46c5-4e16-8b9c-179153b0eebe" xlink:to="loc_us-gaap_AccountsReceivableMember_ac84e9f6-2de2-48bd-80a4-e5865d20a200" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_3ca18956-5093-4959-9be0-3ed6d7420459" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_49edfe81-e0ad-4263-b66d-a1aacbeb988a" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_3ca18956-5093-4959-9be0-3ed6d7420459" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_3ca18956-5093-4959-9be0-3ed6d7420459_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_3ca18956-5093-4959-9be0-3ed6d7420459" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_3ca18956-5093-4959-9be0-3ed6d7420459_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_6c205d2d-821a-4a15-9bcd-87fe261dfe99" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_3ca18956-5093-4959-9be0-3ed6d7420459" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_6c205d2d-821a-4a15-9bcd-87fe261dfe99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_78b9ab44-7552-47d6-91b6-b81c322b9750" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_6c205d2d-821a-4a15-9bcd-87fe261dfe99" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_78b9ab44-7552-47d6-91b6-b81c322b9750" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/IncomeTaxesDeferredTaxAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#IncomeTaxesDeferredTaxAssetsandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/IncomeTaxesDeferredTaxAssetsandLiabilitiesDetails" xlink:type="extended" id="i26ee712595114f21a4c786b3af23be65_IncomeTaxesDeferredTaxAssetsandLiabilitiesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_502f8d74-17d2-402e-a5b6-03538e766948" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLossCarryforwardsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_502f8d74-17d2-402e-a5b6-03538e766948" xlink:to="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_7ac30a68-d57f-4475-a39a-52cf13f1a87d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_7ac30a68-d57f-4475-a39a-52cf13f1a87d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities_7a559a45-af0d-4d67-9fd6-3d5b1b279589" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities_7a559a45-af0d-4d67-9fd6-3d5b1b279589" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsDeferredIncome_d56384b9-2328-4fc3-b688-a0c08a2dc75f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsDeferredIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsDeferredIncome_d56384b9-2328-4fc3-b688-a0c08a2dc75f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_432ce0a2-3b11-4d29-b782-fe0fe56571d9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_432ce0a2-3b11-4d29-b782-fe0fe56571d9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_7c1b6509-6a93-4bfc-9c82-0984968ab3ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_7c1b6509-6a93-4bfc-9c82-0984968ab3ea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_DeferredTaxAssetsGoodwill_3e2b76c6-033c-43dc-b564-40199646043d" xlink:href="glow-20221231.xsd#glow_DeferredTaxAssetsGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_glow_DeferredTaxAssetsGoodwill_3e2b76c6-033c-43dc-b564-40199646043d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsInventory_1529b1b8-ebf8-46da-b960-c3721c80b956" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsInventory_1529b1b8-ebf8-46da-b960-c3721c80b956" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_b8075217-7a50-4f0f-b487-f004c9a34be3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets_b8075217-7a50-4f0f-b487-f004c9a34be3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_f4076199-68c2-4ec9-be32-cf6270bb52e2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_f4076199-68c2-4ec9-be32-cf6270bb52e2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsOther_d6ab71e0-fe0f-45ec-b864-3ee4aadad695" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsOther_d6ab71e0-fe0f-45ec-b864-3ee4aadad695" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOther_01a3c3ab-b680-4efe-9303-8f681dd46763" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsOther_01a3c3ab-b680-4efe-9303-8f681dd46763" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsGross_7361275e-4331-4bb3-b17b-14118cecd8b0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DeferredTaxAssetsNetAbstract_b66c41f6-2b40-432e-b264-17bc63532321" xlink:to="loc_us-gaap_DeferredTaxAssetsGross_7361275e-4331-4bb3-b17b-14118cecd8b0" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_32e3739a-8f85-4b20-83a3-cb0655e7f690" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_502f8d74-17d2-402e-a5b6-03538e766948" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_32e3739a-8f85-4b20-83a3-cb0655e7f690" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_409bbcee-440e-41f8-b663-bf004e7c739c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_502f8d74-17d2-402e-a5b6-03538e766948" xlink:to="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_409bbcee-440e-41f8-b663-bf004e7c739c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_5fbbe3f0-ca22-4e63-a19e-abeb2aacf3a6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLossCarryforwardsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_502f8d74-17d2-402e-a5b6-03538e766948" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_5fbbe3f0-ca22-4e63-a19e-abeb2aacf3a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_776cad24-2bd6-47e2-8194-f27fa1bc5b6d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_5fbbe3f0-ca22-4e63-a19e-abeb2aacf3a6" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_776cad24-2bd6-47e2-8194-f27fa1bc5b6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_776cad24-2bd6-47e2-8194-f27fa1bc5b6d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_776cad24-2bd6-47e2-8194-f27fa1bc5b6d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_776cad24-2bd6-47e2-8194-f27fa1bc5b6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_902aa997-8f90-41ff-96cd-5a2eb1a1a051" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_776cad24-2bd6-47e2-8194-f27fa1bc5b6d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_902aa997-8f90-41ff-96cd-5a2eb1a1a051" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_e7292c1f-0879-44ef-afc0-f4302fb6d046" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_902aa997-8f90-41ff-96cd-5a2eb1a1a051" xlink:to="loc_us-gaap_DomesticCountryMember_e7292c1f-0879-44ef-afc0-f4302fb6d046" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_5a37beeb-b53d-475b-b5fd-4358ef0663d4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_902aa997-8f90-41ff-96cd-5a2eb1a1a051" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_5a37beeb-b53d-475b-b5fd-4358ef0663d4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/IncomeTaxesNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#IncomeTaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended" id="i478365c712fd4bfda0f33ba3e2d2de28_IncomeTaxesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLossCarryforwardsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_76c9cf9a-5696-47b4-a930-23bc7a62cbcd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_76c9cf9a-5696-47b4-a930-23bc7a62cbcd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_f20e7bf2-1786-489d-a23b-0796061dcfeb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_f20e7bf2-1786-489d-a23b-0796061dcfeb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_OperatingLossCarryforwardsPermanentLossOfTaxBenefitResultingFromOwnershipChange_7a664ff4-46da-4025-8ff9-71c79210ab28" xlink:href="glow-20221231.xsd#glow_OperatingLossCarryforwardsPermanentLossOfTaxBenefitResultingFromOwnershipChange"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_glow_OperatingLossCarryforwardsPermanentLossOfTaxBenefitResultingFromOwnershipChange_7a664ff4-46da-4025-8ff9-71c79210ab28" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_e15ae319-92ab-42d3-9d00-658abf2eee8f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_OperatingLossCarryforwards_e15ae319-92ab-42d3-9d00-658abf2eee8f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_OperatingLossCarryforwardsSubjectToExpiration_42848cd3-b5ea-410e-bb5e-7bd9e40288d3" xlink:href="glow-20221231.xsd#glow_OperatingLossCarryforwardsSubjectToExpiration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_glow_OperatingLossCarryforwardsSubjectToExpiration_42848cd3-b5ea-410e-bb5e-7bd9e40288d3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_cd6aac95-f783-4374-9ac6-d737584fd593" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch_cd6aac95-f783-4374-9ac6-d737584fd593" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_8e2494f6-0c9d-45b6-a388-b365959f9043" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_8e2494f6-0c9d-45b6-a388-b365959f9043" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_7da20953-aded-4dc8-b179-55410fbe7589" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense_7da20953-aded-4dc8-b179-55410fbe7589" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_30dae850-04a4-4a0b-b71e-b7a540ecfffd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLossCarryforwardsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_8d5c4bc2-2494-42cd-acc7-a9bc8ec22cda" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_30dae850-04a4-4a0b-b71e-b7a540ecfffd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_5b666ec8-2832-4f25-9f2b-3d88068ee2de" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_30dae850-04a4-4a0b-b71e-b7a540ecfffd" xlink:to="loc_srt_OwnershipAxis_5b666ec8-2832-4f25-9f2b-3d88068ee2de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_5b666ec8-2832-4f25-9f2b-3d88068ee2de_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_5b666ec8-2832-4f25-9f2b-3d88068ee2de" xlink:to="loc_srt_OwnershipDomain_5b666ec8-2832-4f25-9f2b-3d88068ee2de_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_92688565-bf00-4d47-9fd0-59d57e5f3f7d" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_5b666ec8-2832-4f25-9f2b-3d88068ee2de" xlink:to="loc_srt_OwnershipDomain_92688565-bf00-4d47-9fd0-59d57e5f3f7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_CollaborationProductsMember_3a1a9cc1-c8c6-43f8-aba9-7d79a841a928" xlink:href="glow-20221231.xsd#glow_CollaborationProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_92688565-bf00-4d47-9fd0-59d57e5f3f7d" xlink:to="loc_glow_CollaborationProductsMember_3a1a9cc1-c8c6-43f8-aba9-7d79a841a928" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_559998c3-b068-4538-a43f-e51e2f20ce6a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_30dae850-04a4-4a0b-b71e-b7a540ecfffd" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_559998c3-b068-4538-a43f-e51e2f20ce6a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_559998c3-b068-4538-a43f-e51e2f20ce6a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_559998c3-b068-4538-a43f-e51e2f20ce6a" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_559998c3-b068-4538-a43f-e51e2f20ce6a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_06050d96-ce38-45aa-b6f0-9b14680c555b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_559998c3-b068-4538-a43f-e51e2f20ce6a" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_06050d96-ce38-45aa-b6f0-9b14680c555b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_9a7868e7-6db2-4f03-a163-5ef6ec30e772" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_06050d96-ce38-45aa-b6f0-9b14680c555b" xlink:to="loc_us-gaap_DomesticCountryMember_9a7868e7-6db2-4f03-a163-5ef6ec30e772" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_2f81ce80-32e7-4def-b622-1a8bd0d0a9b9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_06050d96-ce38-45aa-b6f0-9b14680c555b" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_2f81ce80-32e7-4def-b622-1a8bd0d0a9b9" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.glowpoint.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="simple" xlink:href="glow-20221231.xsd#RelatedPartyTransactionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.glowpoint.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="extended" id="i07833874b6b448a4959c7d91dc791122_RelatedPartyTransactionsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_40145a1d-0064-4391-a13e-ffc5ebc711f6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_d135ba55-e9fe-4ca8-9458-34e5ef573840" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_40145a1d-0064-4391-a13e-ffc5ebc711f6" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_d135ba55-e9fe-4ca8-9458-34e5ef573840" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_42c3b499-09ae-48fa-bdd6-2a98b6482570" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_40145a1d-0064-4391-a13e-ffc5ebc711f6" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_42c3b499-09ae-48fa-bdd6-2a98b6482570" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_d5dd7dff-563a-4dcf-81b7-92ab72a2c078" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_42c3b499-09ae-48fa-bdd6-2a98b6482570" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_d5dd7dff-563a-4dcf-81b7-92ab72a2c078" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_d5dd7dff-563a-4dcf-81b7-92ab72a2c078_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_d5dd7dff-563a-4dcf-81b7-92ab72a2c078" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_d5dd7dff-563a-4dcf-81b7-92ab72a2c078_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_60fe5b7d-3296-462e-8e3a-b6e8c9a94bac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_d5dd7dff-563a-4dcf-81b7-92ab72a2c078" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_60fe5b7d-3296-462e-8e3a-b6e8c9a94bac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_FractionalLaborMember_42a4be2a-5d11-4bab-a813-514df9b85165" xlink:href="glow-20221231.xsd#glow_FractionalLaborMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_60fe5b7d-3296-462e-8e3a-b6e8c9a94bac" xlink:to="loc_glow_FractionalLaborMember_42a4be2a-5d11-4bab-a813-514df9b85165" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d6d96376-e5f8-431a-9c17-58f6c0c71bec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_42c3b499-09ae-48fa-bdd6-2a98b6482570" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d6d96376-e5f8-431a-9c17-58f6c0c71bec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_d6d96376-e5f8-431a-9c17-58f6c0c71bec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d6d96376-e5f8-431a-9c17-58f6c0c71bec" xlink:to="loc_us-gaap_RelatedPartyDomain_d6d96376-e5f8-431a-9c17-58f6c0c71bec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_b506ccb4-6bb8-467a-802c-ee9f07fc751c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_d6d96376-e5f8-431a-9c17-58f6c0c71bec" xlink:to="loc_us-gaap_RelatedPartyDomain_b506ccb4-6bb8-467a-802c-ee9f07fc751c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_glow_BolsterMember_28c792bf-4865-45b7-b628-82f91170c2ea" xlink:href="glow-20221231.xsd#glow_BolsterMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_b506ccb4-6bb8-467a-802c-ee9f07fc751c" xlink:to="loc_glow_BolsterMember_28c792bf-4865-45b7-b628-82f91170c2ea" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
