EXHIBIT
                                                                          5.1


                                               April 28, 1997

Fastcomm Communications Corporation
45472 Holiday Drive
Sterling, Virginia 20166

               Re:  Registration Statement on Form S-3

Dear Sirs:

     We have acted as counsel to FastComm Communications Corporation, a Virginia
Corporation (the "Company"),  in connection with the preparation and filing with
the  Securities  and Exchange  Commission  under the Securities Act of 1933 of a
Registration  Statement on Form S-3 (the "Registration  Statement")  relating to
the  registration  of 3,190,591  shares (the  "Shares") of the Company's  Common
Stock, par value $.01 per share.

     In so acting, we have examined  originals,  or copies exchange or otherwise
identified  to  our  satisfaction,   of  such  corporate   records,   documents,
certificates  and  other  instruments  as in  our  judgement  are  necessary  or
appropriate to enable us to render the opinion expressed below.

     We are of the following opinion:

     1. The  Company  has been duly  incorporated  and is validly  existing as a
corporation in good standing under the laws of the Commonwealth of Virginia.

     2. The Shares have been duly  authorized and when issued will be fully paid
and non-assessable.

     We  consent to the use of this  opinion  as an exhibit to the  Registration
Statement  and to  the  use  of  our  name  under  the  "Legal  Matters"  in the
Registration  Statement.  In giving  this  consent,  we do not admit that we are
acting within the category of persons whose consent is required  under Section 7
of the Securities Act of 1933.

                                            Very truly yours,

                                            /s/ Amon & Sabatini