For more information, please contact:

Brix Networks, jNETx and Telera Complete Interoperability Testing with Sonus Products

WESTFORD, Mass., February 20, 2002 – Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced that Brix Networks, jNETx and Telera have earned the "Powered" partner level in Sonus' Open Services Partner AllianceSM (OSPA) for proven integration with Sonus products. Solutions from these three OSPA members have successfully passed rigorous interoperability tests with Sonus products in the company's OSPA Interoperability Lab located in Richardson, Texas.

The OSPA mission is to empower standards-based interoperability between applications, third-party vendors and Sonus products. Sonus' OSPA Interoperability Lab is uniquely positioned to test packet voice solutions through the use of state-of-the-art testing equipment within environmentally controlled facilities. Once an OSPA member demonstrates interoperability with a Sonus product, the partner becomes "Powered." Sonus and its "Powered" partners offer service providers end-to-end packet-based network solutions using best-of breed technologies and applications.

"Promoting integration between application, softswitch and hardware vendors is a critical element to the success of the Sonus OSPA program," said Terri Griffin, vice president of marketing, Sonus Networks. "With "Powered" partners such as Brix, jNETx and Telera, Sonus helps carriers quickly gain the full benefit of next-generation networks."

The following products have earned "Powered" status in the OSPA:

• The Brix 100 Verifier from Brix Networks is a purpose-built hardware appliance that verifies customer SLAs (Service Level Agreements) by monitoring the service guarantees from the enterprise's perspective, and supports both active testing and passive monitoring of network protocols and services. The Brix 1000 Verifier is a hardware platform deployed throughout the service provider's POPs to measure performance within their networks and across peering points to other providers. The Brix 1000 Verifier provides the visibility and information necessary for real, verified SLAs between multiple carriers and service providers.
  BrixWorx is a carrier-class, scalable, central site software system that delivers the required flexibility and power for designing service assurance measurements, SLA metrics, service thresholds and test schedules. BrixWorx supplies a separate, Web-based subscriber user interface that permits subscribers to monitor, create and view reports about their own SLAs. (www.brixnet.com)
• The jNETx Universal Session Manager provides a realtime (in-session) communication and commerce environment for prepaid and postpaid subscribers. This includes rating, authentication, notification management and payment handling for voice and data services. The jNETx solution provides a network independent application server that allows operators and enterprises to design, test and launch applications that can be securely utilized by either the operator's subscribers or by an enterprise for its own proprietary purposes. (www.jnetx.com)
• Telera offers the Voice Web Application Platform, a robust call and media-processing platform that leverages web-based technologies to deliver enhanced voice applications. This carrier-class platform enables service providers to offer next generation voice applications, including personalized interactive voice response (IVR), speech-enabled self-service, interactive call routing and network-based queuing. Telera's support of open interfaces, such as SIP-based call control and RTP streaming, enables service providers to leverage their embedded technology and infrastructure, including existing switched circuit and Advanced Intelligent Network (AIN) resources, while deploying the next generation of softswitch and IP-centric networking. (www.telera.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 is the first in the industry where product interoperability is verified, trial testing is performed and complete solutions are ultimately produced. To find additional information on the OSPA, including a list of all OSPA partners, log on to http://ospa.sonusnet.com.

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.

Open Services Partner Alliance is a service mark of Sonus Networks and Open Services Architecture is a trademark of Sonus Networks.