For more information, please contact:

New Network Will Support SOFTBANK Group’s “Yahoo! BB” Subscriber Growth, Enable Delivery of New Offerings

CHELMSFORD, Mass., February 17, 2004 – Sonus Networks (Nasdaq: SONS), a leading provider of carrier packet voice infrastructure solutions and SOFTBANK BB Corp. (SBB), one of Japan’s largest broadband communication carriers, today announced that SBB is deploying Sonus infrastructure as part of a multi-million dollar contract to build out a new packet-based, next-generation voice network.  Under terms of the agreement, Sonus is providing its Open Services ArchitectureTM  (OSA), as well as associated SonusCARESM professional services and support.

“SBB has taken a visionary approach in deploying new technologies, and this has given them a distinct competitive advantage,” said Hassan Ahmed, president and CEO, Sonus Networks.  “SBB has had considerable success in delivering broadband communications services across Japan, and we are extremely pleased to be working with them to expand their next-generation voice network.”

SBB launched “Yahoo! BB” jointly with Yahoo Japan Corporation in June 2001 to provide low-cost broadband services, such as high-speed data and video, to the Japanese market.  SBB has implemented a nationwide ADSL (asymmetric digital subscriber loop) network to support the delivery of broadband services, and now has approximately 3.9 million ADSL subscribers.  In April 2002, SBB introduced its broadband voice services, “BB Phone”, and has more than 3 million telephone customers to date. 

SBB was awarded 5.78 million of 8.95 million new IP-based telephone numbers to be issued in Japan, and is expanding its network to accommodate the continued growth in subscribers.  SBB is deploying Sonus’ GSX9000TM Open Services Switch, the InsignusTM Softswitch and the Sonus InsightTM Management System.  Using the network built on Sonus equipment, SBB will provide long distance voice services first for residential subscribers and then for enterprise customers in later deployment phases.

“In building out our network, we were seeking a robust, stable packet voice solution that is proven in the market,” said Junichi Miyakawa, General Manager, BB Phone Division, and Director of the board, SBB.  “Sonus’ voice infrastructure solutions address our requirements for toll-quality voice, system redundancy and the capacity to handle extremely large call volumes.  Moreover, Sonus has significant experience in deploying large-scale packet voice networks with the world’s leading carriers.  No other vendor in the market could offer all of these capabilities in a single package.”

About Softbank Broadband

Company Profile 

About Sonus Networks

Sonus Networks, Inc., is a leading provider of packet voice infrastructure solutions for wireline and wireless service providers.  With its Open Services ArchitectureTM (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 Chelmsford, 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 the “Cautionary Statements” section of Sonus’ Quarterly Report on Form 10-Q, dated November 10, 2003 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.  Risk factors include, among others, unforeseen issues encountered in the completion of the Company’s independent investigation and the year-end audit, the continued adverse effect of developments in the telecommunications industry, Sonus’ ability to grow its customer base, dependence on new product offerings, market acceptance of its products, competition from large incumbent vendors, rapid technological and market change and manufacturing and sourcing risks.  In addition, any forward-looking statements represent Sonus’ views only as of today and should not be relied upon as representing Sonus’ views as of any subsequent date.  While Sonus may elect to update forward-looking statements at some point, Sonus specifically disclaims any obligation to do so.

Sonus is a registered trademark of Sonus Networks.  Open Services Architecture, GSX9000, Insignus and Sonus Insight are trademarks of Sonus Networks.  All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.