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                                                                   EXHIBIT 99.13


                               ACT NETWORKS, INC.
                         NOTICE OF GRANT OF STOCK OPTION

                  Notice is hereby given of the following option grant (the
"Option") to purchase shares of the Common Stock of ACT Networks, Inc. (the
"Corporation"):

                  Optionee:_____________________________________________________

                  Grant Date:___________________________________________________

                  Vesting Commencement Date:____________________________________

                  Exercise Price:  $___________________per share

                  Number of Option Shares:________________shares

                  Expiration Date:______________________________________________

                  Type of Option:          ___ Incentive Stock Option
                                           ___ Non-Statutory Stock Option

                  Date Exercisable:  Immediately Exercisable

                  Vesting Schedule: The Option Shares shall be unvested and
                  subject to repurchase by the Corporation at the Exercise Price
                  paid per share. Optionee shall acquire a vested interest in,
                  and the Corporation's repurchase right shall accordingly lapse
                  with respect to, (i) twenty-four percent (24%) of the Option
                  Shares upon Optionee's completion of one (1) year of Service
                  measured from the Vesting Commencement Date and (ii) the
                  balance of the Option Shares in successive equal monthly
                  installments upon Optionee's completion of each of the next
                  thirty-eight (38) months of Service measured from and after
                  the first anniversary of the Vesting Commencement Date. In no
                  event shall any additional Option Shares vest after Optionee's
                  cessation of Service.

                  Optionee understands and agrees that the Option is granted
subject to and in accordance with the terms of the ACT Networks, Inc. 1995 Stock
Option/Stock Issuance Plan (the "Plan"). Optionee further agrees to be bound by
the terms of the Plan and the terms of the Option as set forth in the Stock
Option Agreement attached hereto as Exhibit A.


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                  Optionee hereby acknowledges receipt of a copy of the official
prospectus for the Plan in the form attached hereto as Exhibit B. A copy of the
Plan is available upon request made to the Corporate Secretary at the
Corporation's principal offices.

                  REPURCHASE RIGHTS. OPTIONEE HEREBY AGREES THAT ALL OPTION
SHARES ACQUIRED UPON THE EXERCISE OF THE OPTION SHALL BE SUBJECT TO A REPURCHASE
RIGHT EXERCISABLE BY THE CORPORATION AND ITS ASSIGNS. THE TERMS OF SUCH RIGHT
SHALL BE SPECIFIED IN A STOCK PURCHASE AGREEMENT, IN FORM AND SUBSTANCE
SATISFACTORY TO THE CORPORATION, EXECUTED BY OPTIONEE AT THE TIME OF THE OPTION
EXERCISE.

                  No Employment or Service Contract. Nothing in this Notice or
in the attached Stock Option Agreement or Plan shall confer upon Optionee any
right to continue in Service for any period of specific duration or interfere
with or otherwise restrict in any way the rights of the Corporation (or any
Parent or Subsidiary employing or retaining Optionee) or of Optionee, which
rights are hereby expressly reserved by each, to terminate Optionee's Service at
any time for any reason, with or without cause.

                  Definitions. All capitalized terms in this Notice shall have
the meaning assigned to them in this Notice or in the attached Stock Option
Agreement.

________________, 199__
      Date


                                                 ACT NETWORKS, INC.


                                                 By:_______________________

                                                 Title:____________________




                                                 OPTIONEE

                                                 Address:___________________




ATTACHMENTS
Exhibit A - Stock Option Agreement
Exhibit B - Plan Summary and Prospectus

                                       2.

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                                    EXHIBIT A

                             STOCK OPTION AGREEMENT



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                                   EXHIBIT B

                          PLAN SUMMARY AND PROSPECTUS


