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                                                                   Exhibit 10.10

                                NX NETWORKS, INC.
                              CONSULTING AGREEMENT

Agreement ("Agreement") dated this 22nd day of December, 2000 by and between Nx
Networks, Inc., a Delaware corporation having its principal office located at
13595 Dulles Technology Drive, Herndon, VA 22071 ("Nx Networks"), and Doug
Mello, an individual residing at the address below his signature ("Consultant").
Nx Networks and Consultant are sometimes referred to hereinafter singly as
"party" and collectively as "parties."

1. TERM. Subject to the terms of this Agreement, the term of this Agreement
shall commence on the date specified above and continue for a period of twelve
(12) months commencing January 3, 2001, provided that unless either party gives
the other notice of termination not later than 15 days before the scheduled
termination of this Agreement, the term shall continue for successive thirty
(30) day periods until either party terminates this Agreement upon thirty (30)
days prior written notice. Notwithstanding the foregoing, this Agreement shall
be void AB INITIO if John Dubois does not sign an agreement to become the chief
executive officer of Nx Networks on or before January 3, 2001.

2.    CONSULTING SERVICES.

      a)   NATURE OF SERVICES. Consultant agrees to perform such consulting
services as are requested of him from time to time by the Chief Executive
Officer of Nx Networks. It is anticipated that the consulting services will
include:

        o   assistance to the Chief Executive Officer of Nx Networks with
            guidance and strategy for the proper organizational structure to
            support strategic markets;

        o   assistance in the recruitment of key personnel;

        o   assistance in the development of substantial business relationships
            with service provider customers and potential customers; and

        o   assistance in obtaining introductions for the Chief Executive
            Officer of Nx Networks with potential service provider customers and
            other strategic relationships identified by the Chief Executive
            Officer of Nx Networks.

      b)   TIME COMMITMENT. Consultant shall devote at least five (5) business
days per month to the performance of his services hereunder. Consultant shall
perform his services at Nx Networks' corporate headquarters in Herndon, Virginia
or such other place as is designated by the Chief Executive Officer of Nx
Networks.

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3.    COMPENSATION.

      a)   RETAINER. Nx Networks shall pay to Consultant a retainer of $10,000
per  calendar  month  during the term of this  Agreement,  prorated  for partial
months, which amount shall be payable within ten (10) days after the end of each
month. In addition,  Nx Networks shall reimburse  Consultant for all expenses he
may incur related to performance  with this  Agreement,  in accordance  with the
expense reimbursement policies of Nx Networks in effect from time to time.

      b)   OPTIONS. Nx Networks shall grant to Consultant 120,000 options to
acquire common stock of Nx Networks pursuant to the 1999 Long Term Incentive
Plan of Nx Networks. The exercise price of such options shall be $.75 per share,
and such options shall vest in equal installments of 20,000 options per month
during the initial six month term of this Agreement. This grant will be
reflected in a grant agreement pursuant to the 1999 Long Term Incentive Plan.

4.    EXCLUSIVE AGREEMENT. On or before January 4, 2001, Consultant shall
resign as a consultant to Redback Networks,  Inc.  Consultant agrees that during
the term of this  Agreement he will not continue with any existing or accept any
new  consulting  or  employment  arrangement  with a person or entity that is in
direct  competition  with Nx Networks  unless  Consultant has obtained the prior
written consent of the Chief Executive Officer of Nx Networks.

5.    CANCELLATION OF SERVICES.  Either party has the option of canceling
this Agreement at any time, effective upon notice to the other of such
termination.

6.    NOTICES. All notices required hereunder shall be given in writing to the
address listed above, either by personal delivery, by first class mail, return
receipt requested, or by telex of facsimile. The date upon which any such notice
is so personally delivered, or the date three (3) days after it is deposited in
the mail, or the date the telex or fax is sent, shall be deemed to be the date
of notice irrespective of the date appearing therein.

7.    INDEPENDENT CONTRACTORS. The relationship of Nx Networks and Consultant
established by this Agreement is that of independent contractors and nothing
contained herein shall be construed to: (i) give either party the power to
direct and control the day-to-day activities of the other; (ii) constitute the
parties as partners, joint venturers, co-owners or otherwise as participants in
a joint or common undertaking; or (iii) allow either party to create or assume
any obligation on behalf of the other for any purpose whatsoever.

8.    ASSIGNMENT.  Any assignment by Consultant of this Agreement or any of
its rights or obligations hereunder, either voluntarily or by operation of
law shall be void without prior written consent of Nx Networks.

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9.    SURVIVAL OF OBLIGATIONS. All obligations of either party which, by their
nature, require performance after the expiration or termination of this
Agreement, shall survive the expiration or termination of this Agreement and
continue to be enforceable.

10.   GOVERNING LAW.  This Agreement shall be governed by and construed in
accordance with the laws of the Commonwealth of Virginia.

11.   PUBLICITY. Neither party shall have the right to include the other party's
name in marketing and other materials or to disclose and/or summarize the
general nature of this Agreement except to comply with employment laws or when
requested to do so in writing by the other party.

12.   ENTIRE AGREEMENT.  This Agreement together with the Appendices attached
hereto, constitutes the entire Agreement between the parties.


Executed as of the date first above written.


Nx NETWORKS, INC.                               Doug Mello

By:_____________________                 Signature:_________________________

Title:__________________                 Address: 10 Ormond Place
                                                  Rye, New York





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