RADVISION AND INGATE SYSTEMS PARTNER TO PROVIDE MULTIPOINT CONFERENCING FOR MICROSOFT UNIFIED COMMUNICATIONS PLATFORM ACROSS EXTERNAL NETWORKS

Partnership Extends Multipoint Conferencing Outside the LAN and Across Corporate Networks, to the Growing Base of Microsoft Office Live Communications Server and Communicator Users

FALL VON – BOSTON CONVENTION & EXHIBITION CENTER – September 11, 2006 – 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, and Ingate® Systems, providing next-generation SIP-based firewall technology, today announced that they will partner to extend the capabilities of RADVISION’s Click to Meet® for Microsoft Office multipoint audio and video conferencing solution for the Microsoft Unified Communications platform.

RADVISION’s Click to Meet for Microsoft Office is a scalable conferencing platform that adds multiparty video and VoIP audio capabilities to Microsoft Office Live Communications Server and Microsoft Office Live Meeting applications, providing a rich conferencing experience. It also provides the option to extend the reach of Live Communications Server and Live Meeting conferences by providing connection to traditional video conferencing systems, telephones, cell phones and 3G video phones.

Microsoft’s Live Communications Server uses the industry-standard protocol Session Initiation Protocol (SIP) with special extensions for conferencing control. Some enterprise firewalls block this SIP traffic and connections cannot be established. Combining Ingate Systems’ far-end firewall/Network Address Translation (NAT) traversal solutions with RADVISION’s Click to Meet for Microsoft Office extends the native firewall traversal capabilities in Click to Meet to support the specific SIP traffic used by Live Communications Server. This allows businesses to utilize the full capabilities of the RADVISION and Live Communication Server solution not just within their own enterprise, but with outside workers, and partners, customers, and vendors who are also using Microsoft’s Live Communications Server.

The Ingate and RADVISION partnership has provided for the design and interoperability testing of the optimized joint solution which allows firewall traversal without compromising an enterprise’s firewall effectiveness. The partnership will continue to provide ongoing interoperability design and testing and joint sales and marketing activities.

“The number of Microsoft Live Communications Server installations is growing significantly. By tapping into this user base, RADVISION together with Ingate Systems is well positioned to lead the market in secure video conferencing solutions that connect to those outside the LAN,” said Olle Westerberg, Chief Executive Officer, Ingate Systems. “Video conferencing is a natural extension to Live Communications Server functions. Ingate is proud to offer secure far-end firewall/NAT traversal to RADVISION’s Click to Meet users with Microsoft’s Live Communications Server as we believe there is a great demand for video conferencing solutions that will connect enterprise users to remote workers, satellite offices, customers, and suppliers.”

“Enabling the rich functionality that Click to Meet for Microsoft Office provides to Microsoft’s Live Communications Server users through NAT and firewalls is very important to our customers,” said Bob Romano, Vice President of Enterprise Marketing at RADVISION. “This enables them to fully utilize RADVISION’s audio and video capabilities with workers outside the corporate network and with customers and suppliers. This partnership with Ingate provides us with an integrated, transparent solution requiring no extra configuration for the end user.”

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 services on converged IP and 3G networks, and highly scalable video-enabled desktop platforms for IP and emerging next-generation networks. For more information about RADVISION, visit www.radvision.com .

About Ingate® Systems

Ingate® Systems develops firewall technology and products that enable SIP-based live communication for the enterprise while maintaining control and security at the network edge. Ingate has a long history of developing next-generation firewall technology that solves the NAT/firewall traversal issue inherent in SIP communications. In addition to an extensive line of Ingate Firewalls®, the company also produces the award-winning Ingate SIParator®, a device that connects to an existing network firewall to seamlessly enable SIP communications. Ingate products currently protect the networks of retail companies, financial institutions, industrial firms, government agencies and small-to-large enterprises throughout Europe, Asia and North America. Ingate Systems AB is headquartered in Sweden with offices in Stockholm and Linköping. Its wholly-owned subsidiary, Ingate Systems Inc., is located in Hollis, New Hampshire, with a U.S. technology center in Frisco, Texas. For more information on Ingate Systems, visit www.ingate.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.

For more information, please contact:

Hillary Call, Public Relations Manager
Ingate Systems
(917) 414-9262
SIP and email: hillary@ingate.com

Corporate Contact, Radvision
Tsipi Kagan
Chief Financial Officer
Tel: 201-689-6340
email: cfo@radvision.com

Media Relations
Kristin Conforti
Dukas Public Relations
Tel: 516-320-6839
SIP and email: kristin@dukaspr.com

Investor Relations
June Filingeri
Comm-Partners LLC
Tel: 203-972-0186
SIP and email: junefil@optonline.net