For more information, please contact:

Voice VPN and Application Server from BayPackets Complete Integration Testing With Sonus' PSX6000 and GSX9000 Switches

WESTFORD, Mass., September 11, 2001 – Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced that BayPackets Inc. of Fremont, Calif., has become the latest company to achieve "Powered" partner status in Sonus' Open Services Partner AllianceSM (OSPA). 

Companies' products become Powered in the OSPA by passing a rigorous set of interoperability tests in Sonus' lab in Richardson, Texas. BayPackets, a developer and marketer of network-independent, carrier-grade, service introduction and implementation solutions for voice networks, has been elevated to the Powered level by successfully integrating its RSI Voice VPN App^(TM) and its RSI Processor 8000^(TM) application server with Sonus' PSX6000^(TM) SoftSwitch and GSX9000^(TM) Open Services Switch.

Sonus' OSPA helps empower standards-based interoperability between applications, third-party vendors and Sonus products by providing a framework for producing end-to-end network solutions. The two-year-old OSPA consists of more than 140 partners, which collectively offer a variety of enhanced services, network infrastructure solutions and next-generation technologies.

"We congratulate BayPackets for taking its partnership to the next level, proving that its voice VPN product can work effectively with Sonus' in a laboratory setting," said Terri Griffin, vice president, marketing, Sonus Networks. "We look forward to working closely with BayPackets, as we do with our other Powered partners, to deliver the industry-leading solutions that carriers and service providers need today to build the networks of tomorrow."

BayPackets markets solutions that telecom service providers can use to rapidly deploy, manage and bill for network-based revenue-generating services across heterogeneous networks. The company's RSI Processor 8000 is an open-architecture, scalable and fault-tolerant service introduction platform. Its RSI Voice VPN App provides voice VPN services over a new packet network, the Public Service Telephone Network or a combined heterogeneous network. The application supports a wide variety of features, including private numbering plans, on- and off-Net calls, statistics and reports, and Web-based provisioning.

"BayPackets delivers next-generation solutions that carriers and service providers can use to generate revenue from enhanced services immediately," said Brian Coulter, vice president, sales and business development, BayPackets. "By teaming with Sonus Networks, we can help our customers leverage the strength of their packet networks and create immediate revenue-generating opportunities to stay competitive."

About Sonus' OSPA

Founded on the combination of Sonus' Open Services Partner Alliance (OSPA) Program and the INIP PoweredSM Partner Program from the acquisition of telecom technologies, inc., the OSPA has gained significant industry momentum, with membership of more than 140 leading independent vendors. The OSPA 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 suite. An integral part of the Sonus OSPA, the Interoperability Laboratory in Richardson, Texas, 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 is a leading provider of voice infrastructure products for the new public network. Sonus' solutions enable service providers to deploy an integrated network capable of carrying both voice and data traffic, and to deliver a range of innovative, new services. The Sonus Open Services Architecture (OSA) and award-winning Packet Telephony suite cut the time-to-market for competitive new service products, allowing carriers and third-party developers to expand market share and build important new revenue streams. Its highly scalable products fully interoperate with and extend the life and utility of today's public network. Sonus embodies in its management and staff decades of experience in developing carrier-class voice, data and multimedia solutions for implementation in the world's largest networks. 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 August 13, 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, integration risks relating to the acquisition of telecom technologies and manufacturing and sourcing risks.

PSX6000, GSX9000 and Open Services Architecture are trademarks of Sonus Networks. Open Services Partner Alliance and INIP Powered are service marks of Sonus Networks. All other company and product names may be trademarks of the company with which they are associated.