Exhibit 4.6

                                    AMENDMENT

                                     TO THE

                          CERTIFICATE OF INCORPORATION

                                       OF

                                NX NETWORKS, INC.

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                                   PURSUANT TO
                 SECTION 242 OF THE DELAWARE GENERAL CORPORATION LAW

                                   ----------

         The  undersigned,  Jay R.  Schifferli,  being Secretary of Nx Networks,
Inc. (the "Corporation"), hereby certifies that:

         1. The name of the  Corporation  is Nx  Networks,  Inc.  The name under
which the Corporation was originally incorporated is Netrix Corporation.

         2. The Certificate of  Incorporation  of the Corporation was filed with
the Secretary of State of the State of Delaware on March 9, 1987.

         3.  The  text  of  the  first   sentence  of  Article   Fourth  of  the
Corporation's  Certificate  of  Incorporation  shall be and hereby is amended to
read in its entirety as follows:

               "FOURTH:  I. The total  number of shares of all  classes of stock
          that the  corporation  shall have  authority  to issue is  86,000,000,
          consisting of (i)  85,000,000  shares of Common Stock,  $.05 par value
          (the "Common  Stock");  and (ii) 1,000,000  shares of Preferred Stock,
          $.05 par value ("Preferred Stock").

         4.  This  Amendment  to  the  Certificate  of   Incorporation   of  the
Corporation was duly authorized by the unanimous written consent of the Board of
Directors of the  Corporation  and the consent of a majority of the  outstanding
shares  of the  Corporation  entitled  to vote on the  proposal  to  adopt  this
Amendment at a duly noticed and conducted  special  meeting of  stockholders  on
March 6, 2001.

         IN WITNESS WHEREOF, the undersigned has subscribed this document on the
29th day of March,  2001, and does hereby affirm,  under the penalty of perjury,
that the statements contained herein are true and correct.

                                           /s/  Jay R. Schifferli
                                           ________________________________
                                           Jay R. Schifferli
                                           Secretary