REAFFIRMATION OF GUARANTY

REAFFIRMATION dated as of August 24, 2011 (this “Reaffirmation”) by Gerald J. Burnett and by Gerald J. Burnett and Marjorie J. Burnett as Trustee for The Gerald J. Burnett and Marjorie J. Burnett Revocable Trust (collectively, the “Guarantor”) in favor of JPMorgan Chase Bank, N.A., formerly known as JPMorgan Chase Bank (the “Bank”).

WHEREAS, Avistar Communications Corporation, a Delaware corporation (the “Obligor”), has executed and delivered to the Bank that certain Second Amended and Restated Revolving Promissory Note (Libor/Prime) dated as of December 22, 2009, as amended, in the maximum principal amount of $8,000,000 (as amended, restated or otherwise modified from time to time, “Note”);

WHEREAS, the Guarantor has executed and delivered to the Bank that certain Third Amended and Restated Guaranty dated as of March 29, 2011, by which the Guarantor guaranteed, among other things, the Obligor’s obligations to the Bank under the Note (the “Guaranty”);

WHEREAS, the Obligor has executed and delivered to the Bank that certain Fifth Amendment dated as of August 24, 2011 to the Note, by which the “Maximum Facility Amount” (as defined in the Note)  would be increased to $9,000,000 (the “Amendment”);

WHEREAS, the Guarantor desires the Bank to execute and deliver the Amendment;

NOW THEREFORE, FOR VALUE RECEIVED, and as an inducement to the Bank to execute and deliver the Amendment, Guarantor, without in any respect limiting the scope of the Guaranty, hereby confirms, acknowledges and agrees that (i) from and after the date hereof the guaranty provided for in the Guaranty shall extend to, cover and guarantee all obligations of the Borrower arising under Note as amended by the Amendment (in addition to any other obligations guaranteed thereby) and (ii) the Guaranty is (and, following the Bank’s execution and delivery of the Amendment, will be) in full force and effect.

This Reaffirmation shall be governed by and construed in accordance with the law of the State of New York applicable to agreements made and to be performed wholly within the State of New York.

IN WITNESS WHEREOF, the undersigned has executed this Reaffirmation as of the date first set forth above.

By:          /s/ Gerald J. Burnett

Gerald J. Burnett

By:          /s/ Marjorie J. Burnett

Marjorie J. Burnett

State of _________

)

) ss.:

County of ________

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On the ____ day of August in the year 2011, before me, the undersigned, personally appeared Gerald J. Burnett, personally known to me or proved to me on the basis of satisfactory evidence to be the individual whose name is subscribed to the within instrument and acknowledged to me that he/she executed the same in his/her capacity, and that by his/her signature on the instrument, the individual, or the person upon behalf of which the individual acted, executed the instrument.

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Notary Public

State of _________

)

) ss.:

County of ________

)

On the ____ day of August in the year 2011, before me, the undersigned, personally appeared Marjorie J. Burnett, personally known to me or proved to me on the basis of satisfactory evidence to be the individual whose name is subscribed to the within instrument and acknowledged to me that he/she executed the same in his/her capacity, and that by his/her signature on the instrument, the individual, or the person upon behalf of which the individual acted, executed the instrument.

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Notary Public