Marconi Chooses RADVISION SIP Toolkit to Power Advanced Desktop Videoconferencing Platform.

Business Editors/High-Tech Writers

SUPERCOMM 2003

Booth #12041, Hall C

GLEN ROCK, N.J.--(BUSINESS WIRE)--June 2, 2003

RADVISION (Nasdaq: RVSN) today announced the successful implementation and use of its award-winning SIP Developer Toolkit for a number of different components in the Marconi (London: MONI) ViPr(TM), a revolutionary real-time, video, voice, and data communications and collaboration platform. The ViPr platform delivers a new level of DVD-quality video and CD-sharp sound for desktop communications (point-to-point and multi-point) and is being publicly demonstrated at the SuperComm trade show and exhibition at the Georgia World Congress Center in Atlanta in the Marconi booth (#12041, Hall C).

The ViPr platform consists of SIP-based end-user videoconferencing and collaboration terminals (appliances), SIP servers that provide call management features to the appliances, SIP-video servers, and gateways to interoperate with existing network facilities, PBXs and the public switched telephone network (PSTN). While ViPr is primarily designed to provide a high-resolution, feature-rich face-to-face virtual presence experience, the SIP-based ViPr system also facilitates multimedia interconnections by integrating with video broadcasts and PC-based collaboration technologies, leveraging the system's SIP-based IP architecture and advanced video and audio servers.

"The advanced functionality of the ViPr solution, which has found particular success in the government and military markets due to its high security, high definition, and ease of use, are all enabled by our choice of using SIP as the IP signaling protocol," said Brian Rosen, Vice President of Technology Introduction for Marconi's Broadband Routing and Switching group. "By using RADVISION's powerful feature-rich SIP toolkit to develop the major components of our solution, we were able to focus on delivering advanced features and functionality. Following its successful introduction into the U.S. government markets, the next step for Marconi is to introduce ViPr into state and local government markets, particularly for telejustice applications in remote arraignments and hearings."

"Marconi's ViPr solution is a powerful new milestone in the industry-wide trend of delivering high-quality, standards-based, feature-rich voice, video and data communications and collaboration platforms to users' desktop for true personal multimedia communications -- all enabled by the convergence of communications over IP," said Boaz Raviv, General Manger of RADVISION's Technology Business Unit. "By choosing SIP as its IP signaling protocol, Marconi not only delivers integrated communications based on a powerful standard but also is able to easily expand the solution to incorporate other IP-based communications technologies as they become available. RADVISION, with its strong track record in providing easy-to-use, feature-rich developer toolkits for IP protocol devices and applications, is proud of its role in enabling the development of this powerful solution."

RADVISION SIP solutions can be found in the following components of the Marconi ViPr solution:

-- Client Products -- Developed with the RADVISION SIP Developer

Toolkit, ViPr's SIP-based end points are as simple to use as a

telephone and more effective and responsive than video

conferencing. ViPr's simple interface, high-resolution,

real-time video and audio provides extremely low latency, with

no motion delay or jitter. The solution can multipoint up to

four remote party video participants in initial versions, with

subsequent releases supporting 14 remote party calls, or

15-way visual conferencing. For desks that do not need full

virtual presence functionality, IP phones are supported as

well by the underlying SIP-based architecture.

-- Proxy Server Products -- Developed using the SIP Developer

Toolkit, the next release of the ViPr SIP Platform Product

provides a variety of signalling services such as

registration, routing, presence, roaming, bandwidth management

and billing for SIP based endpoints.

-- Video Server -- Marconi's ViPr Video Server, developed with

the RADVISION SIP Developer Toolkit, provides a viewable video

stream (with audio) to ViPr endpoints much like a TV channel.

-- Unicast Audio Mixer -- The ViPr Unicast Audio Mixer is a

network resource that delivers audio mixing for SIP end points

that do not have the built-in mixing capability that the ViPr

terminals do. The UAM is a SIP Back-to-Back User Agent 

(B2BUA), built on the RADVISION SIP Developer Toolkit.

-- InterMedia Gateway (IMGW) -- To provide interworking between

different network topologies, Marconi used the RADVISION SIP

Developer Toolkit to develop an InterMedia Gateway, which acts

as an RTP relay, interworking Unicast or multicast IP streams

to ATM point-to-point or point-to-multipoint switched virtual

circuits. The IMGW allows Ethernet-connected ViPr terminals to

maintain end-to-end QoS across multiservice networks. For

example, two sites with Ethernet IP LANs can be interconnected

with an ATM WAN. The InterMedia Gateway will terminate a

multicast stream from one site, originate a point to

multipoint SVC across the WAN to another IMGW, which

terminates a leaf of the P-MP SVC and re-originates a

multicast on the far LAN. The IMGW is another instance of a

B2BUA.

RADVISION's SIP Developer's Toolkit

RADVISION's SIP Toolkit version 2.2 features an open, object-oriented architecture, which makes it both programmer-friendly and highly flexible. It also features multiple layers of APIs, from high-level APIs that hide the complexity of the protocol and enable rapid development of applications, to mid- and low-level APIs that expose the intricacies of the protocol and allow for more detailed customization tuned to the specific requirements of the application or product. The SIP Toolkit version 2.2 contains a full library containing all SIP-specific functionality, including message encoding and decoding, transaction and call management, and many of the SIP extensions such as REFER, Replaces, PRACK, SUBSCRIBE NOTIFY and more. The Toolkit also comes with SDP and RTP/RTCP libraries.

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.

About Marconi Corporation plc

Marconi Corporation plc is a global telecommunications equipment, services and solutions company. The company's core business is the provision of innovative and reliable optical networks, broadband routing and switching and broadband access technologies and services. The company's customer base includes many of the world's largest telecommunications operators.

The company is listed on the London Stock Exchange under the symbol MONI.

Additional information about Marconi Corporation can be found at www.marconi.com.

All rights reserved. All brands or product names are trademarks of their respective holders.

This press release contains forward-looking statements with respect to products, partners, customers, future growth and other matters. Please refer to the Form 20-F report and Form 6-K reports filed by Marconi Corporation plc with the United States Securities and Exchange Commission for a discussion of risks that could cause actual results to differ materially from such statements.