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                                                                    EXHIBIT 10.4


[KBRO LETTERHEAD]



                                      March 14, 2000

PRIVATE AND CONFIDENTIAL

Mr. Peter Madsen
Chairman & CEO
FastComm Communications Corporation
45472 Holiday Drive
Sterling, VA 20166

Dear Peter:

       This letter confirms that Kaufman Bros., L.P. ("Kaufman") has been
retained by FastComm Communications Corporation (the "Company") to act as the
Company's exclusive financial advisor in connection with the acquisition of
Cronus Communications, Inc. and Cronus Technology, Inc. (together, the
"Target").

A. Performance of Services

       Kaufman will provide the Company with investment banking and financial
advice in an attempt to identify, evaluate and negotiate a joint venture,
acquisition, merger, consolidation, reorganization, recapitalization, business
combination, purchase or sale of capital stock or assets outside the ordinary
course of business or other similar transaction (a "Transaction") during the
term of this agreement. Kaufman will assess the financial impact of the various
alternatives available to the Company, as well as examining the effects of any
proposed Transaction upon the Company and its shareholders. In addition, Kaufman
will evaluate offers and, to the extent deemed appropriate, assist and direct
negotiations leading to the conclusion of a Transaction.

B. Compensation for Services

       Merger Fee

       If during the term of this agreement or within one year thereafter the
Company enters into an acquisition, merger, consolidation, reorganization,
recapitalization or business combination with the Target, the Company will issue
to Kaufman 58,824 shares of the Company's restricted Common Stock (the
"Shares"). The Company will register all of the Shares with the SEC as soon as
practicable upon their issuance hereunder but in no event later than 120 days
after the Shares are due to Kaufman.


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                                             FastComm Communications Corporation
                                                                  March 14, 2000
                                                                          Page 2


       Aggregate Consideration

       Aggregate Consideration is defined and computed as the total proceeds and
all other consideration received or receivable upon the consummation of a
transaction (including payments to be made in installments), including cash,
securities, notes, consulting agreements and agreements not to compete. If a
portion of such consideration includes escrowed or contingent payments (whether
or not related to future earnings of operations), Aggregate Consideration will
include such payments only when the conditions for the payment of such amounts
have been satisfied, at which time the Transaction Fee based thereon shall be
paid to Kaufman.

       Out-of-Pocket Expenses

       The Company will reimburse Kaufman for all reasonable out-of-pocket
expenses incurred in performance of this agreement without regard to whether a
Transaction is consummated.

C. Indemnification

       The Company shall indemnify Kaufman in accordance with Exhibit I attached
hereto.

D. Confidentiality

       Any financial or other advice, descriptive memoranda or other
documentation rendered by Kaufman pursuant to this agreement may not be
disclosed publicly or to any third party in any manner without the prior written
approval of Kaufman. All non-public information given to Kaufman by the Company
will be considered as confidential information and shall be maintained as such
by Kaufman until the same becomes known to third parties or the public without
release thereof by Kaufman. Kaufman may advertise the conclusion of a
Transaction in the financial press.

E. Engagement Period

       This engagement shall continue in effect until August 31, 2001 and shall
be automatically renewed for successive monthly periods until terminated in
writing by either the Company or Kaufman. The provisions of the paragraphs
regarding compensation, confidentiality and indemnification shall survive the
term of this Agreement.

       The Company acknowledges that Kaufman is and has been engaged as a
broker, dealer, underwriter, placement agent, finder, advisor, and dealmaker, by
and for other companies in the industry in which the Company is involved.
Accordingly, the Company agrees that Kaufman shall not be required to act
exclusively for the Company and may now and, from time to time in the future,
be engaged by other companies that compete with the Company. Kaufman may, but
shall not be required to bring opportunities to the Company.


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                                             FastComm Communications Corporation
                                                                  March 14, 2000
                                                                          Page 3


F. Miscellaneous

       This agreement sets forth the entire understanding of the parties
relating to the subject matter hereof. This agreement may not be modified or
changed, nor can any of its provisions be waived, except by written agreement
signed by all parties hereto. This agreement shall be governed by and construed
in accordance with the laws of the State of New York. The parties hereto shall
deliver notices to each other by personal delivery or by registered mail (return
receipt requested). The Company and Kaufman expressly waives all right to trial
by jury in any action or proceeding arising out of this letter agreement.

       Please confirm that the foregoing accurately reflects your understanding
of the agreement between us by signing on behalf of the Company and returning to
Kaufman a duplicate of this letter attached hereto, whereupon it shall become a
binding agreement between the Company and Kaufman.


                                            Very truly yours,

                                            KAUFMAN BROS., L.P.


                                            By: /s/ CRAIG D. KAUFMAN
                                               ---------------------------------
                                               Craig D. Kaufman
                                               Chief Executive Officer


ACCEPTED AND AGREED TO:

FASTCOMM COMMUNICATIONS CORPORATION


By: /s/ PETER MADSEN
   ---------------------------------
   Peter Madsen
   Chairman & CEO


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                                             FastComm Communications Corporation
                                                                  March 14, 2000
                                                                          Page 4


                          EXHIBIT I -- INDEMNIFICATION

       The Company agrees that it will indemnify and hold harmless Kaufman, its
affiliates, control persons, officers, directors, employees and agents and each
person who controls Kaufman within the meaning of Section 15 of the Securities
Act of 1933 or Section 20 of the Securities Exchange Act (Kaufman and each such
entity and person being hereinafter called an "Indemnified Party") from and
against any and all losses, claims, damages, liabilities, costs or expenses
(including reasonable attorneys' and accountants' fees), as incurred, to which
such Indemnified Party may become subject which are (a) related to or arise out
of (i) actions taken or omitted to be taken (including any untrue statements
made or any statements omitted to be made) by the Company or (ii) actions taken
or omitted to be taken (including any untrue statements made or any statements
omitted to be made) by an Indemnified Party with the Company's consent or in
conformity with the instructions of, or actions taken or omitted to be taken by
the Company or (b) otherwise related to or arising out of Kaufman's acting
pursuant to this agreement. The Company also agrees to reimburse each
Indemnified Party within 30 days of submission of an invoice with respect
thereto for all expenses incurred (including fees and disbursements of counsel)
in connection with the investigation of or the preparation for or defense of any
pending or threatened formal or informal claim, action, investigation or other
proceeding caused by or arising out of or in connection with Kaufman's acting
pursuant to this agreement, whether or not Kaufman is a named party thereto and
whether or not any liability results therefrom. The Company will not be
responsible, however, for any loss, claim damage or liability for which
indemnification is sought solely pursuant to the first sentence of this
paragraph which a court of competent jurisdiction shall have determined by a
final judgment to have resulted primarily from willful misconduct or gross
negligence on the part of the Indemnified Party seeking indemnification
hereunder.

       Promptly after receipt by any Indemnified Party of notice of any
complaint or the commencement of any action or proceeding in connection with any
matter related to Kaufman's activities pursuant to the letter agreement, Kaufman
will notify the Company in writing of such complaint or of the commencement of
such action or proceeding and if the Company so elects or is requested by
Kaufman, the Company will assume the defense of such action or proceeding,
including the employment of counsel reasonably satisfactory to Kaufman and the
payment of the fees and disbursements of such counsel, in which event the
Company shall not be obligated to pay the fees and disbursements of separate
counsel for Kaufman in such action. However, failure by Kaufman to so notify the
Company of such claim or such commencement shall not relieve the Company from
any obligation hereunder except to the extent that such failure shall result in
prejudice to the Company. In the event, however, that Kaufman's legal counsel
shall determine that defenses may be available to an Indemnified Party that are
different from or in addition to those available to the Company or that there is
or could reasonably be expected to be a conflict of interest by reason of the
Company and an Indemnified Party having common counsel in any action or
proceeding, or if the Company has not assumed the defense of any action or
proceeding, then Kaufman may employ separate counsel to represent or defend it
or any Indemnified Party in any such action or proceeding in which it or such
Indemnified Party


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                                             FastComm Communications Corporation
                                                                  March 14, 2000
                                                                          Page 5


may become involved or is named as defendant and the Company shall pay the fees
and disbursements, as Incurred by such separate counsel; provided that the
Company shall not be obligated to pay the fees and disbursements of more than
one such separate counsel for any one such action or proceeding in any one
jurisdiction.

       If for any reason the foregoing indemnification is unavailable to
Kaufman, or insufficient to hold it harmless, then the Company shall contribute
to the amount paid or payable by Kaufman as a result of such loss, claim, damage
or liability in such proportion as is appropriate to reflect the relative
benefits received by the Company and its stockholders on the one hand and
Kaufman on the other; provided that in no event will the aggregate contribution
by Kaufman hereunder exceed the amount of fees actually received by Kaufman
pursuant to this agreement. It is agreed that the relative benefit of the
Company on the one hand and of Kaufman on the other hand with respect to any
financing shall be deemed to be in the same proportion as (x) the Aggregate
Consideration paid or proposed to be paid in such financing (whether or not such
financing is consummated) bears (y) to the fee payable to Kaufman with respect
to such financing pursuant to this agreement.

       The reimbursement, indemnity and contribution obligations of the Company
under this paragraph shall be in addition to any liability which the Company may
otherwise have and shall be binding upon and inure to the benefit of any
successors, assigns, heirs and personal representatives of the Company, Kaufman
and any such person. The provisions of this Exhibit I shall survive the
termination and expiration of this agreement.