Exhibit 10.27

      1585 Broadway   New York, NY 10036   tel. 212 761-4000

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      January 17, 2002

PERSONAL AND CONFIDENTIAL

Mr. Asghar D. Mostafa
President & CEO
Advanced Switching Communications, Inc.
8330 Boone Boulevard, 5th Floor
Vienna, Virginia 22182

Dear Asghar:

Pursuant to our recent discussions, this letter will confirm that Morgan Stanley
& Co. Incorporated (“Morgan Stanley”) and Advanced Switching Communications,
Inc. (“ASC”) have agreed to modify certain provisions of the engagement letter,
dated as of October 24, 2001 (the “Engagement Letter”), between Morgan Stanley
and ASC as described below. Capitalized terms used but not defined herein shall
have the meanings ascribed to them in the Engagement Letter.

We hereby agree that if a Transaction is accomplished, the Transaction Fee will
be $1,250,000. We further agree that $625,000 will become payable and is to be
paid by ASC by wire transfer upon the signing of a definitive agreement. The
remaining $625,000 of the Transaction Fee will become payable and is to be paid
by ASC by wire transfer in accordance with the terms of the Engagement Letter.

We confirm that the remainder of the terms of the Engagement Letter and the
related Indemnity Letter dated October 24, 2001 remain in full force and effect.

 

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If you are in agreement with the foregoing, please indicate by signing and
returning one copy of this letter, which will constitute our agreement with
respect to the subject matter hereof.

      Very truly yours,     MORGAN STANLEY & CO. INCORPORATED

        By: /s/ James M. Head

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James M. Head
Executive Director

Accepted:

ADVANCED SWITCHING COMMUNICATIONS, INC.

      By: /s/ Sherry L. Rhodes

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Title: VP, GC

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Date: January 25, 2002

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