Former Nortel Networks Executive Brings 15 Years Experience in Global Telecommunications Industry

WESTFORD, Mass., July 29, 2002 - Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced that it has named J. Michael O'Hara to the position of vice president of marketing. In this role, O'Hara will drive all of Sonus' inbound and outbound marketing activities, including product management, product marketing, marketing communications, and media and industry analyst relations. As vice president of marketing, O'Hara reports directly to Sonus president and CEO, Hassan Ahmed.

"Michael's extensive experience in marketing and operations, particularly in international markets, is a tremendous asset to Sonus as we move forward in creating and delivering solutions for large, global telecommunications providers," said Ahmed. "Michael will be instrumental in driving critical initiatives that will enable us to expand our market presence, and we're extremely pleased to welcome him to the Sonus Networks organization."

"Having worked in the telecom industry for my entire career, I understand the opportunities and challenges facing service providers as they transition to next-generation networks," said O'Hara. "Sonus is clearly recognized as a leader in the carrier packet voice market, and I look forward to working with the team here to make Sonus a significant company in one of the world's most exciting industries."

Before joining Sonus, O'Hara spent 15 years at Nortel Networks, holding a variety of management positions in marketing, sales, manufacturing and general operations. Most recently, O'Hara served as vice president of marketing at Nortel Networks. In that role, he had responsibility for Nortel's marketing and sales operations programs in Europe, the Middle East and Africa, directing functions such as public relations, advertising, government relations, analyst relations, trade shows, events, customer training, account marketing and geographic marketing.

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 May 10, 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 emerging 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 is a trademark of Sonus Networks. All other company and product names may be trademarks of the respective companies with which they are associated.