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                                                                  EXHIBIT 10.8.2


      MODIFICATION #6 TO PREFERRED SUPPLIER AGREEMENT DATED JUNE 24, 1997
                                 ("AGREEMENT").
     Effective Date of Modification November 27,2000 ("Modification Date").

The parties hereby agree that as of the Modification Date, certain terms and
conditions of the Agreement, as expressly modified below, shall apply and that
this Modification #6 shall take precedence over the terms contained in the
Agreement and any prior modifications:

1. DEVELOPMENT EFFORTS: In consideration of the order under this Modification
#6, agrees to deliver the software enhancements to Avistar as specified below,
by the dates specified:

(i)  T6000 additional feedback and [***] code - see Attachment I

(ii) T500 dataport feedback enabled software version. - Delivery by no later
than [***]

Avistar's take-down period for the T6000/2500 order specified in Section 2 below
shall commence [***] days after delivery of the B.2 software and shall extend
for a period of [***] months thereafter ("Take-Down Period"). In addition, the
Take-Down Period shall be subject to Tandberg meeting the additional
requirements specified in Attachment I. Any delay in delivery of the software
enhancements will result in an associated extension of the Take-Down Period.

2. ADDITIONAL T6000/2500 CODEC ORDER: Subject to Tandberg's agreement that these
codec units will be manufactured and supported as standard off-the-shelf
products, Avistar agrees to take delivery of, and pay for, a minimum of [***]
Tandberg codecs over the course of the [***] month period following delivery of
the software enhancements specificed in the above Section 1(i) at the prices
shown below.

[***] Total Codecs (but no less than the quantities of each shown below):

(i)  No less than [***] codecs shall be T6000 codecs (base including
     H.323/320/768kbs/PRI/E1/E1PRI/BRI) at a per unit price of $[***] plus a
     maintenance fee of $[***].

(ii) T2500 codecs (384 kbs, plus all above except PRI/E1 PRI) at a per unit
     price of $3,750 plus a maintenance of $[***] The current delivery schedule
     for the first [***] codec units shall be in four equal increments, over the
     first [***] months during the Take-Down Period, with the last [***] codecs
     to be delivered no later than the last ([***]) month of the Take-Down
     Period.

3. ADDITIONAL T500 CODEC ORDER: Avistar agrees to take delivery of, and pay for,
a minimum of [***] x T500 codecs at a per unit price of $[***] plus a
maintenance fee of $[***]. Avistar agrees to a delivery schedule for the [***]
units as follows:

Delivery Schedule:

25% of [***] units [***] days from delivery to Avistar of the software
enhancements in 1 above.
25% in the succeeding [***] days
50% in the [***] days after that.

In consideration for the delivery schedule, Tandberg will provide Avistar an
extended warranty for T500 codecs purchased hereunder of [***] months. T500
codecs will be 384 kbs version.

4. SUPPORT PROVISIONS: Tandberg agrees to use all reasonable commercial efforts
to support Avistar following the procedures described in Attachment II.

5. DEMO/TEST UNITS AND LOANERS: For each Tandberg system Avistar sells, Avistar
shall be entitled to receive [***] free units for its own internal use,
demonstration and testing purposes. Additional units shall be purchased by
Avistar. For purposes of this Modification #6, upon execution of this
Modification #6, Tandberg will provide Avistar the following codec units at no
charge:

[***] x T6000 codecs ([***] already shipped to Avistar under Modification #5)
[***] x T500 codecs (this is contingent upon return by Avistar of the [***] x
T800 units currently on loan to Avistar)
In addition, within one-week from execution of this Modification #6, Tandberg
will ship [***] additional T6000 codec units to Avistar as an advance shipment
against the [***] codec unit order described in Section 2 above. Tandberg agrees
that payment for these units will be deferred, and these units will be invoiced
by Tandberg and paid for by Avistar in conjunction with payment for the first
delivery during the Take-Down Period.

6. ADDITIONAL CONSIDERATIONS: The following additional considerations are agreed
to by the parties and are incorporated into this Modification #6:

(A) Tandberg may, at its discretion, supply Avistar a T6000 codec model that
does not [***] .

(B) Avistar will be able to continue ordering in the Avistar BOM configurations,
including prices for cables and NT384, agreed under Modification #5 except that
the codec will be replaced with the T6000 or T2500 codec, as the case might be.

(C) If Tandberg releases a next generation upgrade to the codecs being purchased
hereunder during the specified take-down period of this Modification #6, Avistar
will have the right to request substitution of order balance with the upgraded
model

7. JOINT PRESS RELEASE: The parties will issue a joint press release announcing
the joint product offering and Avistar's intent to incorporate Tandberg's
end-point hardware into the Avistar system. A November 28, 2000 release date is
planned.

Except as expressly modified by this Modification #6, all terms and conditions
of the Agreement, including previous modifications, shall remain in full force
and effect. The parties agree that this Modification #6 may be executed via
facsimile and that it shall be considered equivalent to an executed original
when signed (via facsimile) by both parties; nevertheless, any one of the
parties may require the follow-up exchange of originals in hardcopy by so
requesting in writing within five (5) days of facsimile execution.

IN WITNESS WHEREOF, THE PARTIES HAVE CAUSED THIS MODIFICATION #5 TO BE EXECUTED
BY THEIR AUTHORIZED REPRESENTATIVES:

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<CAPTION>
AVISTAR SYSTEMS CORPORATION                               TANDBERG INC.
<S>                                                       <C>
By:                 signature on file                     signature on file - Colin Stutervant
                    -----------------------------------   ------------------------------------
Printed Name/Title: Rima Vanhill, Director of Contracts   Printed Name/Title:
                    -----------------------------------                       ------------------------------
</TABLE>


[***] CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.
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                                  ATTACHMENT I

THE FOLLOWING REPRESENTS A LIST OF ADDITIONAL FEEDBACK INFORMATION REQUIREMENTS
OF AVISTAR FOR H.323, AND TANDBERG'S AGREED SCHEDULE FOR RELEASE:

B.2 SOFTWARE RELEASE: Using its best commercial efforts, Tandberg agrees to
deliver the B.2 Software to Avistar as follows:
In Beta Release - no later than [***]
In Production Release - no later than [***]

PARTIALLY SUPPORTED IN B.2: This functionality will be partially supported in
B.2. The remaining functionality will be handled as with the "Not in B.2" items.

NOT IN B.2: For Items Listed below as Not in B.2, Tandberg agrees to use its
best commercial efforts to deliver the enhancements and features as soon as
possible thereafter including delivery of an interim release after B.2 and
before the next Tandberg production release. In any event, Avistar will be
provided this functionality by no later than the earlier of (i) Tandberg's next
production release after B.2 (i.e. B.3); or (ii) the end of [***].

The following is the additional feedback information that must be provided
(mandatory) to support H.323 in order for Avistar to proceed fully with its
development to support T platform:

[***]



[***] CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO
THE OMITTED PORTIONS.
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                                  ATTACHMENT II

FIRST AND SECOND LINE SUPPORT RESPONSIBILITIES OF AVISTAR AND TANDBERG:

AVISTAR SUPPORT: Avistar provides and is responsible for tier one and two
support of all Tandberg product Avistar deploys. Tier one and two support
includes, answering usage questions, codec failure diagnosis and replacement,
codec configuration and Telco problem identification and resolution management.
Avistar requires tier three support from Tandberg through a single
systemengineer responsible for all support requests including, the investigation
and any required resolution for suspected software bugs and hardware design
product failures, Telco compatibility resolutions and work-arounds not covered
by Tandberg documentation, and the fulfillment of any escalated on-site tier
three support requests for on-going issues that cannot be duplicated in a lab
environment.

TANDBERG SUPPORT: The Tandberg system engineer is responsible for the management
and execution of all Avistar tier three support requests and shall be familiar
with Avistar's deployment of Tandberg product. The system engineer is required
to notify Avistar in advance of any planned absence or personal holiday plans
and provide contact information for the engineer who will be acting in their
capacity during their absence.

ON-GOING SUPPORT: Tandberg's system engineer and Avistar will meet once every
month by video to discuss the status of open issues and planned resolutions.
Additional Tandberg resources with required specific expertise will be available
from time to time to work with Avistar on the resolution of tier three support
issues at the discretion of Tandberg.

RESPONSE TIMES: All requests for tier three support will receive a response
within one business day. All open tier three support requests will be resolved
or have a resolution plan and completion date within one week of the initial
support request. Tandberg will define the method Avistar shall use for
requesting tier three support. Tandberg will keep a status log of Avistar's tier
three support requests and provide reports upon request.

SUPPORT CONTACTS: PRIMARY US TECHNICAL CONTACT
                  PRIMARY TECHNICAL CONTACT IN NORWAY
                  PRIMARY CONTACT FOR ORDERS/RMAS