LONDON and SAN MATEO, California, July 21 /PRNewswire/ --

- Avistar's C3 Technology's User-Friendliness and Cost-Effectiveness 
Essential to Addressing Client Needs in Challenging Global Markets

- Expansion of Reseller Channel Key Component of Company's Strategy

Avistar Communications Corporation (Nasdaq: AVSR), a leading provider of
unified visual communications solutions, has signed a strategic partnership
agreement with City Information Services Limited (CityIS Ltd.), a global
visual communications company. The agreement offers CityIS' clients a
cost-effective, user-friendly and proven desktop videoconferencing solution
that is built to easily interoperate with room solutions and extend video to
the desktop, office, home or on the road.

In making the announcement, Darren Innes, General Manager, Worldwide
Sales, Avistar, said, "CityIS is a significant player in our strategy to
deliver our C3 solutions through the reseller channel. CityIS has more than a
decade of specialized experience in the videoconferencing space, and knows
first-hand what its clients need to remain competitive in today's challenging
global marketplace. With offices around the world servicing global clients,
CityIS offers a breadth and depth of channel coverage that will be
instrumental in our goal of making Avistar desktop videoconferencing as
ubiquitous as large room implementations."

John N. Thompson, Founder and Chairman of CityIS, said, "More and more,
our clients see the value of videoconferencing as a means to boost workplace
efficiency, optimize supply chain operations, accelerate decision-making and
reduce carbon emissions. This agreement allows us to complement our extensive
videoconferencing offerings with an easy-to-use, intuitive desktop solution
that maximizes the productivity of users and does not disrupt the workflow
they have underway at their desks."

Ira Weinstein, Senior Analyst and Partner, Wainhouse Research, said,
"Today's challenging economic climate has spawned increased interest in both
group and desktop/personal videoconferencing. CityIS' experience selling and
supporting professional videoconferencing solutions makes them well suited to
offer Avistar's C3 integrated desktop conferencing solution to its roster of
enterprise clients."

About CityIS Ltd.

CityIS is a global visual communications company, assisting many Fortune
500 organizations realize their ROI and environmental goals through video
communications. Its technical and commercial consultancy capabilities ensure
that clients optimize videoconferencing to transform the way they
communicate. CityIS underpins its consultation process with an unrivalled
breadth of global services to ensure total project ownership through the
delivery, management and measurement stages, to guarantee a fully managed and
successful project lifecycle. CityIS' unrivalled global coverage spans 92
countries worldwide. Corporate offices are located throughout EMEA, USA and
APAC. For more information, visit http://www.cityis.com.

About Avistar Communications Corporation

Avistar creates technology that provides the missing critical element in
unified communications: bringing people in organizations face-to-face,
through enhanced communications, for true collaboration anytime, anyplace.
Its latest product, Avistar C3, draws on over a decade of market experience
to deliver a single-click desktop videoconferencing and collaboration
experience that moves business communications into a new era. Available as a
stand-alone solution, or integrated with existing unified communications
software from other vendors, Avistar C3 users gain instant messaging-style
ability to initiate video communications across and outside the enterprise.
Patented bandwidth management enables thousands of users to access desktop
videoconferencing, Voice over IP (VoIP) and streaming media, without
requiring substantial new network investment or impairing network
performance. Avistar's desktop videoconferencing and collaboration
installations are among the world's largest, including more than 18,000 seats
sold in more than 40 countries. Clients report as much as a 20 percent
reduction in travel expense and carbon emissions, increases in productivity,
and immeasurably improved relationship building within their organizations,
as well as with suppliers and customers. Avistar holds a portfolio of 80
patents for inventions in video and network technology and licenses IP to
videoconferencing, rich-media services, public networking and related
industries. Current licensees include Sony Corporation, Sony Computer
Entertainment Inc. (SCEI), Polycom, Inc., Tandberg ASA, Radvision Ltd. and
Emblaze-VCON. For more information, visit http://www.avistar.com.

Web site: http://www.avistar.com
              http://www.cityis.com