– Board Approved Program Authorizes Buy Back of Up To $30 Million of Stock –

Tel Aviv (November 21, 2007) –

RADVISION (Nasdaq: RVSN), a leading provider of video network infrastructure and developer tools for unified visual communications over IP, 3G, and emerging next-generation IMS networks, announced today that it has received approval from the District Court in Tel Aviv Jaffa to repurchase up to $30 million of its common stock under a Board-approved share repurchase program. The approval was required in accordance with Section 333 of the Israeli Companies Laws, 1999. The program will comply with Securities and Exchange Commission Rule 10b-18. The program, which is now effective, will be carried out according to the guidelines of the Board of Directors of RADVISION.

RADVISION currently has 21,761,491 basic shares of common stock outstanding.

About RADVISION

RADVISION (Nasdaq: RVSN) is the industry’s leading provider of market-proven products and technologies for unified visual communications over IP, 3G and IMS 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 video conferencing systems, innovative converged mobile services, and highly scalable video-enabled desktop platforms on IP, 3G and emerging next-generation IMS networks. For more information about RADVISION, visit http://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.

Source: RADVISION