For more information, please contact:

Sonus' Family of Wireless Solutions Provides Carriers Cost-Effective, Flexible Alternative to Traditional Wireless Infrastructure, Paves Way to All-IP Next-Generation Wireless Networks

WESTFORD, Mass., February 18, 2003 – Sonus Networks (Nasdaq: SONS) today announced that it has extended its product set to meet the unique requirements of wireless operators with the availability of SMARRTTM Wireless, a family of packet-based wireless switching solutions. Sonus' SMARRT Wireless solutions allow carriers to cost-effectively deploy and operate wireless networks, increase network capacity to accommodate growing subscriber traffic, and build new revenue streams and customer loyalty through the delivery of packet-based enhanced services. 

"Facing intense competition and pressure on profit margins, wireless operators are seeking opportunities to reduce the cost of building and operating their networks and to generate new revenue streams," said Michael O'Hara, vice president, marketing, Sonus Networks. "Taking the experience we've gained in the wireline world, Sonus offers solutions for today's wireless networks that enable carriers to lower their network lifecycle costs and improve their market positions."

SMARRT Wireless is based on Sonus' Open Services ArchitectureTM (OSA), which has been deployed in wireline carrier networks for nearly four years and now supports 4 billion minutes of traffic per month. Key components in the SMARRT Wireless solutions include the GSX9000TM Open Services Switch, the InsignusTM Softswitch and the Sonus InsightTM Management System. Sonus' wireless solutions deliver the features and protocol support necessary for rapid deployment in all wireless network environments including GSM, CDMA, TDMA and 3G.

Sonus offers wireless operators a family of mobile switching solutions designed to dramatically improve the economics of network deployment and operations. These solutions can be deployed individually or together to minimize capital outlays and maximize profitability. Carriers can implement the packet-based SMARRT Wireless solutions in the 2G and 2.5G networks in service today, while enabling a seamless migration to 3G networks in the future.

The SMARRT Wireless solution set addresses a range of core carrier applications:

Gateway Mobile Switching Center (GMSC) – The Sonus solution provides GMSC capabilities for wireless networks, including support for key protocols such as IS-41 and GSM-MAP. The Sonus GMSC interacts with the Home Location Register (HLR) to direct incoming calls to the MSC currently serving the mobile subscriber. Not burdening home MSCs with calls to roaming subscribers frees up revenue-generating capacity on legacy MSC switches and reduces the cost of inter-MSC trunks.

Wireless Transit/Tandem Switching – Deploying Sonus' voice infrastructure solutions reduces network cost and complexity by interconnecting MSCs via a packet core in large metropolitan or regional areas. This not only reduces core network costs and minimizes routing translations, but also simplifies routing and provisioning on MSCs by replacing many small trunks with fewer large trunks.  

Wireless Long Distance – In this application, carriers implement packet voice technologies to build their own transport networks rather than purchasing wholesale long distance services from other carriers. This can yield significant cost savings for wireless operators, as well as rapid payback periods.  

Next-Gen Mobile Switching Center (MSC) – Sonus' media gateway, the GSX9000 Open Services Switch, has been enhanced to support industry-standard wireless interfaces, ensuring interoperability with standards-based wireless softswitches to provide robust Next-Gen MSC capabilities.

"From an OPEX standpoint, the wireless operator business case for deploying packet voice infrastructure solutions to optimize existing wireless networks is clear-cut given the mandate to cut costs. Even from a CAPEX perspective, with an eye towards IP-centric 3G, operators understand the value of packet-based voice gear and have been moving in this direction," notes Peter Jarich, senior analyst for Wireless Infrastructure with Current Analysis. "In this respect, Sonus is addressing a real market need, targeting some often overlooked, but important carrier pain points."

Sonus' SMARRT Wireless solutions also facilitate the cost-effective and flexible delivery of IP-based enhanced services. Rather than backhauling calls to a central system or deploying multiple expensive legacy application platforms, enhanced services can be offered at the source by centrally maintained application logic. Multiple services can be deployed together, and simplified provisioning and management can be centralized in one location.

In addition to the wireless solutions Sonus is delivering today, the company announced that it is pursuing the development of the all-IP wireless voice network. The 3G Release 5 wireless network architectures closely mirror those currently deployed and in service with Sonus' wireline customers across the globe.  

"The industry is moving to an end goal of the all-IP wireless network, and we believe the work that we have completed with landline carriers ideally positions Sonus to understand the challenges and solutions required to deliver the all-IP 3G environment," continued O'Hara.

Sonus' SMARRT Wireless solutions are commercially available and are being deployed in wireless service provider networks today.

About Sonus Networks

Sonus Networks, Inc., is a leading provider of packet voice infrastructure products for the new public network. 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 Sonus' Quarterly Report on Form 10-Q, dated November 13, 2002 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.

Open Services Architecture, SMARRT, GSX9000, Insignus and Sonus Insight are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.