Exhibit 10.2

                                     [LOGO]
                                     iBEAM
                                  BROADCASTING

                           Overflow Service Agreement

      THIS OVERFLOW SERVICE AGREEMENT (this "Agreement") is made and entered
into as of June , 2001 (the "Effective Date") by and between iBEAM BROADCASTING
CORPORATION, a Delaware corporation with its principal offices in Sunnyvale,
California ("iBEAM") and WILLIAMS COMMUNICATIONS, LLC, a Delaware corporation
with its principal offices at One Williams Center, Suite 2700, Tulsa Oklahoma
74172 ("Williams").

      WHEREAS, Williams desires to purchase from iBEAM, and iBEAM hereby agrees
to provide to Williams the Services on the iBEAM Network, each in accordance
with the terms and conditions of this Agreement;

      NOW, THEREFORE, in consideration of the mutual covenants and agreements
contained herein and for other good and valuable consideration the receipt and
sufficiency of which is hereby acknowledged, the parties agree as follows:

A.    Service Agreements.

      iBEAM and Williams may hereinafter enter into one or more mutually agreed
upon written agreements (each a "Service Agreement") pursuant to which iBEAM
shall provide to Williams the following streaming media services (the "Services)
over iBEAM's proprietary network of servers, satellite, and terrestrial
connectivity (the "iBEAM Network"):

      1.    Media On-Demand (as defined in the Media On-Demand Service
            Agreement);

      2.    Live Event Streaming Service (as defined in the Live Event Streaming
            Service Agreement);

      3.    24x7 Live Streaming Service (as defined in the 24x7 Live Streaming
            Service Agreement); and

      4.    Spontaneous Live Streaming Service (as defined in the Spontaneous
            Live Streaming Service Agreement).

B.    Pricing.

      Williams hereby agrees to the price schedule set forth in Exhibit A. iBEAM
and Williams agree to incorporate the pricing terms set forth in Exhibit A into
iBEAM's then current Service Agreements for a period until December 31, 2001. To
any extent any conflict shall exist between a provision contained in a Service
Agreement and a provision contained in Exhibit A, the provision in Exhibit A
shall control. Thereafter, iBEAM and Williams shall negotiate in good faith the
pricing terms for incorporation into subsequent Service Agreements, with the
limitation that such newly negotiated pricing terms shall not exceed the pricing
terms set forth in Exhibit A.

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C.    Term.

      The term of this Agreement (the "Term") shall be coterminous with the
Master Alliance Agreement between iBEAM Broadcasting Corporation and Williams
Communications, LLC dated.

D.    Miscellaneous.

      1. If any provision of this Agreement is held by a court or arbitrator of
competent jurisdiction to be invalid, void, or otherwise unenforceable, the
remainder of this Agreement shall remain in full force and effect and shall in
no way be invalidated, void, or voidable as a result thereof.

      2. This Agreement constitutes the entire agreement and understanding
between the parties with respect to the subject matter hereof.

      3. No modification of this Agreement shall be valid unless in a writing
signed by each party.

      4. The waiver of any breach or failure of a term or condition of this
Agreement by any party shall not be construed as a waiver of any subsequent
breach or failure of the same term or condition, or a waiver of any other breach
or failure of a term or condition of this Agreement.

      5. This Agreement shall be governed by, and construed in accordance with,
the laws of the State of California, without giving effect to procedural rules
or legal principles regarding conflicts of laws.

      6. This Agreement shall be binding upon and shall inure to the benefit of
the parties hereto and their respective successors and assigns.

      7. This Agreement may be executed in one or more counterparts, each of
which will be deemed an original, but all of which together shall constitute one
and the same instrument.

      8. This Agreement shall not be assigned by a party without the prior
written consent of the other party, which consent shall not be unreasonably
withheld. Notwithstanding the foregoing, either party hereto shall have the
right to assign this Agreement to any entity that such party controls, is
controlled by, or is under common control with, or to a successor by merger of
such party or to a successor to all or substantially all of such party's assets.

E.    Additional Terms and Conditions.

      The additional terms and conditions set forth in Exhibit A attached hereto
are hereby incorporated herein by reference.


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<PAGE>

      IN WITNESS WHEREOF, iBEAM and Williams have caused this Agreement to be
executed by their respective duly authorized representatives.

iBEAM Broadcasting Corporation

By:    /s/ Peter Desnoes
       -----------------
Name:  Peter Desnoes
       -------------
Title: CEO
       ---


Williams Communications, LLC

By:    /s/ John Bumgarner
       ------------------
Name:  -------------------------
Title: -------------------------


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<PAGE>

                                   Exhibit A
                         to Overflow Service Agreement

      Pursuant to the terms of the Agreement, Williams shall pay to iBEAM fees
for the Services specified in each Service Agreement as follows:

A. Media On-Demand; Live Event Streaming Service, 24x7 Live Streaming Service,
and Spontaneous Live Streaming Service.

      1.    Transport Fee.

            Williams agrees to pay to iBEAM a transport fee (the "Transport
Fee") for Content distributed over the iBEAM Network, in accordance with the
following (select one):

            Transport Volume              MBT (megabytes transferred)
            During Relevant Month         Price
            ------------------------------------------------------------

            < 40,000 MBT                  $0.0042
            > 40,000 MBT                  $0.0038
            > 50,000 MBT                  $0.0030

      For purposes of the Transport Fee, the volume of Content transported is
measured at the point that Content leaves the iBEAM Network.

      2.    Storage Fee.

            Williams hereby agrees to pay to iBEAM a storage fee (the "Storage
Fee") for Content stored by iBEAM within the iBEAM Network, in accordance with
the following:

            $30.00 per gigabyte (GB) stored per month

      For purposes of the calculating the Storage Fee for any particular month,
the volume of Content stored is measured at the highest volume of Content stored
at any time during such month. The Storage Fee is not applied to copies of
Content created by iBEAM for storage on multiple servers within the iBEAM
Network. Each month during the Term of each Service Agreement, Williams shall
pay the Storage Fee as calculated by the number of GBs for such month x the
applicable GB price.

      3.    Acquisition Fee.

            Williams hereby agrees to pay to iBEAM an acquisition fee (the
"Acquisition Fee") pertaining to the acquisition of the Content by iBEAM from
Williams, in accordance with the following:

                  Method of Acquisition              Acquisition Fee
                  --------------------------------------------------
                  Internet Acquisition:              No Charge
                  T1 Based Acquisition:              iBEAM's cost plus 10%


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<PAGE>

      4.    Set-up Fee.

            With regard to the Live Event Streaming Service and the 24x7 Live
Streaming Service, Williams shall pay a set-up fee of $1,000.00 for each open
URL.


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