RADVISION Announces New Release of Its Award-Winning SIP Toolkit for Communications Systems Development.

FAIR LAWN, N.J. -- RADVISION (Nasdaq:RVSN):

--The New SIP Toolkit is the Industry's State-of-the Art Development Tool for Real-Time Carrier-Class Applications, Such as VoIP and Instant Messaging Networks

RADVISION (Nasdaq:RVSN), a leading provider of multimedia conferencing and communications platforms, today announced the immediate availability of version 4.0 of its award-winning session initiation protocol (SIP) toolkit for real-time communication applications such as voice over IP (VoIP) and instant messaging (IM).

"The entire telecommunications market is in the midst of a major migration from traditional TDM (time-division multiplexing) technology to SIP technology," said Adi Paz, Senior Director of Product Management and Marketing for RADVISION's Technology Business Unit. "RADVISION's SIP Toolkit 4.0 is a key enabler for this migration."

Specifically developed to address carrier-side applications, such as soft switches, gateways, and application servers, the RADVISION SIP Toolkit 4.0 can support millions of busy hour call attempts (BHCAs) and has been enhanced with carrier-grade features including a reliable and effective Stream Control Transmission Protocol (SCTP) layer and automatic translation between phone numbers and SIP addresses (ENUM).

Using advanced design techniques, RADVISION has optimized the SIP Toolkit 4.0 for a small footprint, allowing it to serve efficiently in SIP terminals and IP handsets as well as network-side implementations.

Other significant enhancements in this new release include:

--Connection reuse: optimizing the efficient use of network resources for SIP signaling

--Support for new SIP addressing schemes, including TEL for telephony applications, PRES for presence applications, and IM for instant messaging applications

--Additional security features including secured RTP (SRTP) and Multimedia Internet Keying (MIKEY)

--Support for mobile carrier applications, including IMS mobile registration and special SIP headers and extensions

Considered the industry-leader, RADVISION's award-winning SIP Toolkit is a high-performance SIP implementation that provides multiple application program interface (API) layers for optimal control and flexibility when developing new products and services. Designed from the ground up to be a powerful and highly versatile set of development tools, it addresses and simplifies the development of communications systems and devices based on IETF SIP including key 3GPP extensions.

About RADVISION

RADVISION LTD. (Nasdaq: RVSN) is the industry's leading provider of high quality, scalable and easy-to-use products and technologies for videoconferencing, video telephony, and the development of converged voice, video and data over IP and 3G networks. For more information please visit our website at 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.