Exhibit 10.4

                           Wire One Technologies, Inc.
                                 225 Long Avenue
                           Hillside, New Jersey 07205

                                                                   July 30, 2002
Mr. Jonathan Birkhahn
258 Riverside Drive, #8D
New York, New York 10025

Dear Jon:

      This letter, when accepted by you, shall constitute an amendment to the
employment agreement (the "Agreement"), dated November 30, 2000, between Wire
One Technologies, Inc. (the "Company") and you. The Company and you hereby agree
as follows:

      1. The Company has requested that, to contribute to an improvement in the
Company's financial condition and for no other reason, you agree, as an
amendment to paragraph 2(a) of the Agreement, to reduce your base salary
compensation thereunder so as to be payable at the rate of (a) $247,000 per
annum during the period commencing on August 5, 2002, through November 29, 2002,
and (b) $270,750 per annum during the period commencing on November 30, 2002,
through November 29, 2003. In consideration of the agreement by several other of
the Company's executives to salary reductions similar in nature, you hereby
agree to the salary reduction set forth in the preceding sentence.

      2. Except as modified hereby, the Agreement remains in full force and
effect.

                                        Yours very truly,

                                        WIRE ONE TECHNOLOGIES, INC.

                                        By: /s/ Richard Reiss
                                            ----------------------------
                                            Richard Reiss

ACCEPTED:

/s/ Jonathan Birkhahn
----------------------------
Jonathan Birkhahn