Sonus Delivers New DataStream Integrator Module for Billing Mediation; Provides Enhanced Security and Back-Office Features in EMS

WESTFORD, Mass., March 25, 2002 - Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced it is delivering a range of powerful new billing, security, OSS (operations support system) integration, and performance management features in its Sonus Insight Management System. Available in Sonus' recently introduced Release 4.0 software, these enhancements to Sonus Insight allow carriers to more effectively provision, operate and bill for services on their networks.

"Robust network management capabilities are critical to the seamless deployment and reliable operation of packet voice networks," said Mike Hluchyj, founder and chief technology officer, Sonus Networks. "Sonus Insight addresses carriers' stringent requirements, leveraging next-generation management technologies, while also supporting the legacy systems used by incumbent carriers today."

The latest version of Sonus Insight incorporates an important new component, the DataStream Integrator (DSI), an advanced billing integration solution providing unique features and tools to expedite back-office integration. The DSI compiles billing data from multiple sources, correlates the data and produces standards-compliant billing streams based on customer-specific services and billing usage criteria. The DSI also supports standard distribution methods such as Telcordia's Automatic Message Accounting Data Networking System (AMADNS) and can be customized to support any third-party or legacy system.

"Clearly, the ability to bill for services is vital to the success of our business," said Guillermo Larios, technology manager, Alestra. "We sought a complete solution that would enable us to transition telephony services from the circuit to packet network without disrupting our existing billing and customer care infrastructures. Sonus Insight seamlessly integrates our current back-office systems with the Sonus equipment, allowing us to leverage our existing investments while benefiting from the latest technologies."

Sonus also introduced new system security capabilities in Sonus Insight's Element Management System (EMS), providing advanced security measures at multiple levels. For example, using Secure Socket Layer (SSL) between users and the EMS provides robust encryption, preventing access from unauthorized personnel. Communication links between the EMS and network elements are also secured through the use of the Secure Shell (SSH) protocol. The User Security Manager offers new features that allow system administrators to more easily define security roles and access restrictions based on organizational structure. Sonus Insight's ability to integrate with centralized security managers using the RADIUS protocol allow carriers to take advantage of advanced authorization methods such as RSA Security's RSA SecureID.

As carrier customers continue to deploy Sonus' systems and increase the number of minutes on their networks, robust reporting capabilities become even more critical. To that end, Sonus has made a number of enhancements to Sonus Insight's reporting features, including the ability to map service level entities to the underlying physical infrastructure. Sonus also provides live inventory reports that allow the carrier to track their investments in real-time. These reports can be viewed from a web browser, exported to the user's desktop, as well as pushed to an OSS on a scheduled basis. With this release, Sonus also continues to expand its flow-through provisioning capabilities in the areas of automated routing and subscriber provisioning using the latest technologies such as Java RMI and XML/SOAP. Legacy systems can access these same capabilities using Telnet or CORBA IIOP.

Earlier this year, Sonus completed the Telcordia Technologies OSMINE process, allowing it to offer full capacity and provisioning integration for Sonus solutions within a Regional Bell Operating Company (RBOC) environment. Sonus Insight supports a number of Telcordia OSS including the TIRKS, NPM, NCM and NMA systems. In Release 4.0, Sonus Insight provides new OSMINE monitoring capabilities to ensure that mission-critical operations data is transmitted to the Telcordia OSS and that the upstream systems are receiving the data appropriately.

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 14, 2001, 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 Company's 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.

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