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Newest Open Services Partner Alliance Members Provide Solutions Including Enhanced Services Applications and Operator Services

WESTFORD, Mass., September 10, 2003 – Sonus Networks (Nasdaq: SONS), a leading provider of carrier packet voice infrastructure solutions, today announced that Intelis Inc., RADVISION Ltd. (Nasdaq: RVSN) and Vero Systems have joined Sonus' Open Services Partner AllianceSM (OSPA).  

"The OSPA brings Sonus together with leading telecom hardware and software vendors providing a range of products such as enhanced services applications, network infrastructure and operations support systems (OSS)," said Michael O'Hara, vice president, marketing, Sonus Networks. "We are pleased to work with the companies entering the program today to expand the solutions options available to carriers."

Partners joining the OSPA today deliver solutions including:

• Intelis offers the Intelis Enhanced Operator Services (EOS) platform, a fully-featured Operator Services solution that completes, tracks and rates toll calls billed via BOC card, credit card, collect, third party or sent paid (bill to ANI). The Intelis EOS features a user-friendly administration system and a flexible GUI-based IVR to enable service customization. The EOS also integrates seamlessly with third party Directory Assistance applications. www.intelis-inc.com
• RADVISION delivers the viaIP(™) videoconferencing product family, a complete set of multipoint conferencing units, data collaboration, gateways, gatekeepers (ECS), utilities and applications for rich media collaborative communications in large-scale enterprise, carrier and distributed network deployments. www.radvision.com
• Vero Systems provides the Acuite AcuRoute Automated Optimal Routing solution. An integrated solution, AcuRoute maximizes the per call margin through the automation of Least Cost Routing (LCR) across on-net and off-net carriers. Additionally, AcuRoute improves customer satisfaction and call completions through timely and accurate NPA/NXX updates and provides immediate realization of cost savings due to minimized requirements for technicians. www.verosystems.com

About Sonus' OSPA

Sonus Networks' Open Services Partner Alliance program provides a framework that offers service providers end-to-end packet-based network solutions using best-of-breed technologies and applications. The goal of the OSPA is to empower standards-based interoperability between applications, hardware vendors, and the Sonus product family. An integral part of the Sonus OSPA, the OSPA Interoperability Laboratory verifies product interoperability, performs trial testing and ultimately produces complete solutions. To find additional information on the OSPA, including a list of all OSPA partners, log on to http://www.sonusnet.com/partners.

About Sonus Networks

Sonus Networks, Inc., is a leading provider of packet voice infrastructure solutions for wireline and wireless service providers. With its Open Services Architecture (™) (OSA), Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking, residential access and Centrex, tandem switching, and IP voice termination, as well as enhanced services. Sonus' award-winning voice infrastructure solutions, including media gateways, softswitches and network management systems, are deployed in service provider networks worldwide. Sonus, founded in 1997, is headquartered in Westford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

This release may contain projections or other forward-looking statements regarding future events or the future financial performance of Sonus that involve risks and uncertainties. Readers are cautioned that these forward-looking statements are only predictions and may differ materially from actual future events or results. Readers are referred to the "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated August 13, 2003 and filed with the SEC, which identifies important risk factors that could cause actual results to differ from those contained in the forward-looking statements. These risk factors include, among others, the adverse effect of recent developments in the telecommunications industry, the weakened financial position of many service providers, Sonus' ability to grow its customer base, dependence on new product offerings, market acceptance of its products, rapid technological and market change and manufacturing and sourcing risks. In addition, any forward-looking statements represent Sonus' views only as of today and should not be relied upon as representing Sonus' views as of any subsequent date. While Sonus may elect to update forward-looking statements at some point, Sonus specifically disclaims any obligation to do so.

Sonus is a registered trademark of Sonus Networks. Open Services Architecture, GSX9000, Insignus and Sonus Insight are trademarks of Sonus Networks. Open Services Partner Alliance is a service mark of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.