Industry Pioneers to Dramatically Improve Organizational Productivity through High Definition Multi-participant Conferencing and Advanced Gateway Support

Lifesize®, the high definition video communications company, and RADVISION (Nasdaq: RVSN), a leading provider of video network infrastructure and developer tools for unified visual communications over IP, 3G, and emerging next-generation networks, today announced a collaboration effort to strengthen interoperability between their respective product lines. Through this joint initiative, Lifesize and RADVISION will deliver distributed organizations with a dramatic improvement in productivity through high definition multi-participant conferencing and advanced gateway support.

The industry partnership will ensure seamless integration between Lifesize’s flagship product, Lifesize® Room™ – a high definition video communications product that delivers crystal clear video and high fidelity audio – and RADVISION’s recently released SCOPIA v.5 Multipoint Control Unit (MCU), which will provide multi-participant high definition (HD) video and high fidelity audio in an upcoming software upgrade. Together, Lifesize and RADVISION are demonstrating the significance of bringing high definition video – a market pioneered by Lifesize – to multi-participant conferencing and the impact it is having on the industry’s shift towards this next generation technology.

“High definition video communications is offering customers a much richer conferencing experience than traditional standard definition offerings. Revolutionary products like Lifesize Room have already changed our industry’s landscape,” said Boaz Raviv, RADVISION’s CEO. “Coupled with RADVISION’s market leading MCUs and gateways, customers will have access to a complete high definition solution from endpoints to infrastructure and gateways to bridge to other networks and devices. We are excited to partner with the leader in high definition video and provide a communications platform that fully supports the Lifesize product line.”

“We are pleased to partner with a market leader like RADVISION for shaping the future of high definition video communications,” said Craig Malloy, CEO of Lifesize. “Lifesize customers have shown great interest in high definition multipoint conferencing so we look forward to collaborating with RADVISION on products and initiatives that benefit our mutual clients while expanding our respective industry leadership positions.”

About RADVISION

RADVISION (Nasdaq: RVSN) is the industry’s leading provider of market-proven products and technologies for unified visual communications over IP and 3G networks. With its complete set of standards-based video networking infrastructure and developer toolkits for voice, video, data and wireless communications, RADVISION is driving the unified communications evolution by combining the power of video, voice, data and wireless – for high definition videoconferencing systems, innovative converged mobile services, and highly scalable video-enabled desktop platforms on IP, 3G and emerging next-generation networks. For more information about RADVISION, visit www.radvision.com.

This press release contains forward-looking statements that are subject to risks and uncertainties. Factors that could cause actual results to differ materially from these forward-looking statements include, but are not limited to, general business conditions in the industry, changes in demand for products, the timing and amount or cancellation of orders and other risks detailed from time to time in RADVISION’s filings with the Securities Exchange Commission, including RADVISION’s Form 20-F Annual Report. These documents contain and identify other important factors that could cause actual results to differ materially from those contained in our projections or forward-looking statements. Stockholders and other readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date on which they are made. We undertake no obligation to update publicly or revise any forward-looking statement.