<PAGE>
                                                                   EXHIBIT 10.93


                          Williams Communications, LLC
                           One Williams Center, MD 26
                           Tulsa, Oklahoma 74172-0712


                                                      October 11, 2001

iBEAM Broadcasting Corporation
645 Almanor Avenue, Suite 100
Sunnyvale, CA 94085

Ladies and Gentlemen:

         Reference is made to the Debtor-in Possession Term Credit and Security
Agreement (the "Agreement"), dated as of October 11, 2001, among iBEAM
Broadcasting Corporation, a Delaware corporation (the "Borrower"), debtor and
debtor-in-possession in a case pending under Chapter 11 of the Bankruptcy Code
(the "Case") and Williams Communications, LLC ("Williams"), a Delaware limited
liability company, as lender (in such capacity, the "Lender").

         Capitalized terms used herein and not otherwise defined herein shall
have the meanings assigned to such terms in the Agreement.

         You agree to pay to the Lender a facility fee equal to 0.50% of the
Commitment (the "Facility Fee") on the Closing Date.

         On the date (the "Termination Date") of the consummation of the sale by
the Borrower of substantially all of its assets to Williams pursuant to Section
363 of the Bankruptcy Code, as contemplated by and in accordance with the Asset
Sale Agreement, the amount of the outstanding Obligations required to be repaid
by the Borrower to the Lender on the Termination Date shall be decreased by the
amount of the Facility Fee.

         You agree that, except as set forth above, once paid, the Facility Fee
or any part thereof payable hereunder shall not be refundable under any
circumstances, regardless of whether the transactions contemplated by Asset Sale
Agreement are consummated. The Facility Fee payable hereunder shall be paid in
immediately available funds and shall be in addition to reimbursement of the
Lender's out-of-pocket expenses.



<PAGE>


         This Fee Letter is the fee letter referred to in Section 2.11 of the
Agreement. The Facility Fee is in addition to, and not in lieu of, any other
fees charged to Borrower under the Agreement and the other Loan Documents.

         This Fee Letter may not be amended or waived except by an instrument in
writing signed by the Lender and you. This Fee Letter shall be governed by, and
construed in accordance with, the laws of the State of New York. This Fee Letter
may be executed in any number of counterparts, each of which shall be an
original, and all of which, when taken together, shall constitute one agreement.
Delivery of an executed signature page of this Fee Letter by facsimile
transmission shall be effective as delivery of a manually executed counterpart
hereof.

         You agree that this Fee Letter and its contents are subject to the
confidentiality provisions of the Agreement.


                  [Remainder of page intentionally left blank]



                                        2

<PAGE>

                                            WILLIAMS COMMUNICATIONS, LLC


                                            /s/ JOHN BUMGARNER
                                            -------------------------------
                                            Name:
                                            Title:

Accepted and Agreed to by:


iBEAM BROADCASTING CORPORATION


/s/ PETER DESNOES
-------------------------------
Name:
Title:



                                        3