Sonus Networks Provides Internet Call Diversion Solution for BellSouth

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Sonus Equipment Enables Leading RBOC to Efficiently Manage Internet and Voice Traffic

WESTFORD, Mass., July 11, 2001 – Sonus Networks (Nasdaq: SONS) today announced that BellSouth Corporation (NYSE: BLS) has chosen Sonus' award-winning packet voice infrastructure solutions to further enhance BellSouth's data services. BellSouth will implement a Sonus packet voice solution as the foundation for offloading Internet traffic from its circuit-switched voice network.  

"BellSouth is aggressively transforming its network to meet the demands of new data services, while continuing to provide efficient voice applications," said Ray Smets, vice president of Network Transformation for BellSouth Corporation. "Sonus' ICD solution is a critical step in BellSouth's network migration to support more packet-based data services."

BellSouth plans to deploy Sonus solutions that include the GSX9000 Open Services Switch, the PSX6000 SoftSwitch, the SGX2000 SS7 Signaling Gateway and the Sonus Insight Element Management System. BellSouth will utilize Sonus technology to supplement its existing Class 5 circuit switches, offloading modem-generated Internet traffic from its voice network. In this application, Internet traffic destined for remote access servers is diverted away from circuit switches before it enters the voice infrastructure, thus freeing up network resources. With the new packet-based infrastructure in place, BellSouth also has the ability to expand beyond the initial Internet call diversion application to deliver voice services on the same packet platform.

"In deploying a packet-based infrastructure, BellSouth furthers its reputation as one of the most innovative and technologically advanced of the Regional Bell Operating Companies (RBOCs)," said Hassan Ahmed, president and CEO, Sonus Networks. "We are gratified to have been selected by BellSouth as their vendor of choice for the ICD project."

BellSouth is expected to deploy Sonus ICD solutions in at least 8 major metro areas within the Southeast in the next year.  

"Implementing the Internet Call Diversion solution from Sonus will relieve potential pressure points in BellSouth's network that could be caused by large volumes of traffic destined for the Internet," said Christin Flynn, director, Carrier Convergence Infrastructure, the Yankee Group. "Furthermore, this architectural decision opens up the opportunity for BellSouth to deliver packetized voice services in the future, enabling enhanced, revenue-generating services they cannot offer today. For Sonus, this represents a significant turning point. The company takes on the network of a demanding class of customer with high reliability requirements: the local incumbents."

About BellSouth Corporation

BellSouth Corporation is a Fortune 100 communications services company headquartered in Atlanta, GA, serving more than 45 million customers in the United States and 16 other countries. Consistently recognized for customer satisfaction, BellSouth provides a full array of broadband data and e-commerce solutions to business customers, including Web hosting and other Internet services. In the residential market, BellSouth offers DSL high-speed Internet access, advanced voice features and other services. BellSouth also provides online and directory advertising services, including BellSouth(R) RealPagesSM.com. BellSouth owns 40 percent of Cingular Wireless, the nation's second largest wireless company, which provides innovative wireless data and voice services.

About Sonus Networks

Sonus Networks, Inc. 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 ArchitectureTM (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 marketshare 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 May 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, integration risks relating to the acquisition of telecom technologies and manufacturing and sourcing risks.

GSX9000, PSX6000, SGX2000, Sonus Insight and Open Services Architecture are trademarks of Sonus Networks. All other company and product names may be trademarks of the respective companies with which they are associated.