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                                                                       Exhibit 5


             Opinion and Consent of Brobeck, Phleger & Harrison LLP


                                  June 8, 1998

ACT Networks, Inc.
188 Camino Ruiz
Camarillo, California 93012


Re: ACT Networks, Inc. Registration Statement for Offering
of an additional 250,000 Shares of Common Stock

Ladies and Gentlemen:

        We refer to your registration on Form S-8 (the "Registration Statement")
under the Securities Act of 1933, as amended, of an additional 250,000 shares of
Common Stock under the Company's 1997 Non-Executive Officer Stock Option/Stock
Issuance Plan (the "Plan"). We advise you that, in our opinion, when such shares
have been issued and sold pursuant to the applicable provisions of the Plan and
in accordance with the Registration Statement, such shares will be validly
issued, fully paid and non-assessable shares of the Company's Common Stock.

        We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.

                                        Very truly yours,

                         /s/ BROBECK, PHLEGER & HARRISON LLP
                         
                         BROBECK, PHLEGER & HARRISON LLP



