Seasoned Sales and Marketing Expert Will Drive Sonus' Leadership In Carrier-Class Voice-Over-Packet Switching; Rogers to Direct the Market Entry of the Award-Winning Sonus Gateway Switch (GSX9000).

WESTFORD, Mass., March 22, 1999 - Sonus Networks, an emerging leader in carrier-class Voice-Over-Packet solutions that fully integrate with the existing public voice network, today announced the appointment of industry veteran Gary Rogers as Vice President of Sales and Marketing. Rogers is charged with bringing to market the award-winning Sonus GSX9000 Gateway Switch, the industry's only "any-to-any" Voice-Over-Packet central office switch that extends the scalability, lifecycle and services potential of today's public voice network. Rogers will be responsible for the development of the company's direct and channel sales force, marketing staff and growing customer base.

"The public network is about to be transformed by a new breed of open, packet-based central office switches that will forever change the economics and competitive dynamics of the carrier market through the immediate delivery of innovative new services," noted Sonus President and CEO Hassan Ahmed. "Gary's industry vision and market development experience will enable our carrier customers to realize the true potential of convergence, and help establish Sonus as a leader in this multi-billion dollar market."

"This is a particularly crucial and formative stage in the evolution of the public network, one in which carriers urgently seek IP Telephony solutions that let them build new services revenue streams, and that fully integrate with their existing SS7-based circuit switch infrastructure," Rogers said. "I look forward to driving the introduction of the market's first such solutions, and to working with our customers to define and grow this important new market."

Rogers joins Sonus from Security Dynamics, where, as Senior Vice President of World Wide Sales and Operations, he conceived and successfully drove the company's evolution to a multi-channel sales model and its expansion into the European and Pacific Rim markets, more than doubling the company's revenues.

Previously, as Bay Networks' Vice President of International Sales, based in France, he more than doubled the company's revenue growth through the development and direction of direct sales and strategic channels sales programs and initiatives. Under his guidance, Bay's Field Marketing operations established and sustained the highest levels of market visibility and reach.

Rogers has also held strategic sales and market expansion positions with IBM and several of the data communications industry's most respected start-up organizations. He holds a Bachelor of Science Degree in Mathematics from Dartmouth College and a Masters in Business Administration from the University of Chicago.

About Sonus Networks

Sonus Networks, Inc. is developing and marketing the next generation of carrier-grade IP telephony for the public voice network. Its equipment facilitates the movement of telephony from traditional circuit networks to packet networks, enabling a host of new carrier and end user services. The Sonus management and engineering teams have proven success records, having led organizations such as Ascend Communications, recently acquired by Lucent Technologies (Nasdaq: LU) and Summa Four, recently acquired by Cisco (Nasdaq: CSCO), where they directed the development and delivery of carrier-class equipment to support data, voice and multimedia information. Sonus Networks was recently awarded the prestigious Hot Startup of the Year Award by Data Communications Magazine, which also awarded the Sonus GSX9000 the Hot Product of the Year Award. Sonus also received the 1999 Investor's Choice Award at Technologic Partners' Network Outlook Conference.