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                                                                    EXHIBIT 10.6

                               EXTENSION AGREEMENT

     This Extension Agreement is entered into as of September 13, 2004 between
Silicon Valley Bank ("Silicon"), and First Virtual Communications, Inc ("First
Virtual") and Cuseeme Networks, Inc. ("Cuseeme") (First Virtual and Cuseeme
being referred to herein jointly and severally as "Borrower"), with reference to
the following facts:

     A.   Silicon and the Borrower are parties to that certain Loan and Security
Agreement dated April 3, 2003 (as amended, the "Loan Agreement") and that
certain Temporary Forbearance Agreement dated as of September 13, 2004 (the
"Forbearance Agreement"). (Capitalized terms used in this Agreement, which are
not defined herein, shall have the meanings set forth in the Forbearance
Agreement. The Loan Agreement, the Forbearance Agreement and all other present
and future documents, instruments and agreements relating thereto are referred
to herein collectively as the "Loan Documents".)

     B.   Borrower has requested an extension of the Forbearance Period, and
Silicon is willing to grant such extension on the terms and conditions set forth
herein.

     NOW, THEREFORE, THE PARTIES AGREE AS FOLLOWS:

1. Extension of Forbearance Period. Contingent on receipt of the principal
reduction referred to in Section 2 below, the date "September 21, 2004" in
Section 1.1 of the Forbearance Agreement is hereby amended to read "October 4,
2004", so that Section 1.1 reads as follows:

          " 1.1 Forbearance. Silicon agrees to forbear from exercising its
          rights and remedies against the Borrower, as a result of the Existing
          Defaults, until the earlier of the following dates (the `Forbearance
          Period'): (i) October 4, 2004, or (ii) the date any Additional Default
          shall occur. In agreeing to forbear from exercising its rights and
          remedies, Silicon is not waiving the Existing Defaults or any rights
          or remedies in connection therewith, all of which are expressly
          reserved. Upon the expiration of the Forbearance Period, Silicon may,
          at its option, exercise any and all rights or remedies in connection
          with the Existing Defaults, without further notice."

2. Principal Reduction. Borrower shall concurrently pay to Silicon the sum of
$500,000 to be applied to the Obligations in such order as Silicon shall
determine in its discretion.

3. No Commitment as to Further Extensions. Borrower acknowledges that Silicon,
by entering into this Agreement and discussing further forbearance and/or
restructuring with respect to the Loan Agreement, is not agreeing or committing
to any further extension of the Forbearance Period or any further forbearance
and/or restructuring with respect to the Loan Agreement, and no such agreement
or commitment shall be effective against Silicon unless set forth in a specific
written agreement signed by Silicon.


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4. General Provisions.

     4.1. Incorporation by Reference. All of the general provisions in Section 5
of the Forbearance Agreement shall apply to this Agreement and the same are
incorporated herein by this reference.

     4.2. Agreements Continue. As modified herein, the Forbearance Agreement and
the other Loan Documents shall continue in full force and effect, and the same
are hereby ratified and confirmed.

     4.3. Governing Law; Forum Selection. This Agreement is being entered into
in the State of California. This Agreement shall be governed by the laws of the
State of California. As a material part of the consideration to the parties for
entering into this Agreement, each party (1) agrees that, at the option of
Silicon, all actions and proceedings based upon, arising out of or relating in
any way directly or indirectly to, this Agreement shall be litigated exclusively
in courts located within Santa Clara County, California, (2) consents to the
jurisdiction of any such court and consents to the service of process in any
such action or proceeding by personal delivery, first-class mail, or any other
method permitted by law, and (3) waives any and all rights to transfer or change
the venue of any such action or proceeding to any court located outside Santa
Clara County, California.

     4.4. MUTUAL WAIVER OF RIGHT TO JURY TRIAL. EACH PARTY TO THIS AGREEMENT
HEREBY WAIVES THE RIGHT TO TRIAL BY JURY IN ANY ACTION OR PROCEEDING BASED UPON,
ARISING OUT OF, OR IN ANY WAY RELATING TO: (I) THIS AGREEMENT OR ANY OF THE
OTHER LOAN DOCUMENTS; OR (II) ANY OTHER PRESENT OR FUTURE INSTRUMENT OR
AGREEMENT BETWEEN OR AMONG THEM; OR (III) ANY CONDUCT, ACTS OR OMISSIONS OF ANY
PARTY TO THIS AGREEMENT OR ANY OF THEIR DIRECTORS, OFFICERS, EMPLOYEES, AGENTS,
ATTORNEYS OR ANY OTHER PERSONS AFFILIATED WITH THEM; IN EACH OF THE FOREGOING
CASES, WHETHER SOUNDING IN CONTRACT OR TORT OR OTHERWISE.

"Borrower":                                   "Borrower":

Cuseeme Networks, Inc.                        First Virtual Communications, Inc


By: /s/ Truman Cole                           By: /s/ Truman Cole
   ----------------------------                   ------------------------------
   Title: VP/CFO                                  Title: VP/CFO


"Silicon":

Silicon Valley Bank


By: /s/ Cynthia A. Bitner
   -----------------------------
   Title: Vice President


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