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Q1 Revenues Grow to $41.5 Million, Increase 45% Over Preceding Quarter

WESTFORD, Mass., April 10, 2001 – Sonus Networks, Inc. (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today reported financial results for its first quarter ended March 31, 2001. 

Revenues for the first quarter of fiscal 2001 were $41.5 million compared with $28.6 million for the fourth quarter ended December 31, 2000, an increase of 45 percent. Net income for the first quarter of fiscal 2001, excluding stock-based compensation, amortization of goodwill and purchased intangibles and an in-process research and development charge relating to the acquisition of telecom technologies, inc., completed in January 2001, was $0.2 million or $0.00 per share, compared with net income, excluding stock-based compensation, of $0.1 million or $0.00 per share on a pro forma basis for the fourth quarter of fiscal 2000.

Net loss for the first quarter, including stock-based compensation, amortization of goodwill and purchased intangibles and an in-process research and development charge, was $82.5 million or $0.51 per share, compared with a net loss of $6.3 million or $0.04 per share for the fourth quarter of fiscal 2000.

"We are extremely gratified with our results this quarter," said Hassan Ahmed, president and CEO, Sonus Networks. "During the quarter, we continued to execute on our business strategy and have made significant progress across several fronts. We expanded our customer base, delivered new product capabilities and features, broadened our partner program and have made great strides in the integration of telecom technologies following the completion of the acquisition in January. We're off to a great start this year."

In March, Sonus announced that it signed a multi-year, multimillion-dollar contract with Qwest Communications. Qwest has selected Sonus' packet voice technology for deployment in Qwest's nationwide, all-optical IP network. Qwest is building its next-generation voice network using the full range of Sonus solutions, including the GSX9000 Open Services Switch, the INtelligentIP Softswitch, which was gained through the acquisition of telecom technologies, inc., the PSX6000 SoftSwitch and the SGX2000 SS7 Signaling Gateway. Qwest also announced its first suite of services based on the Sonus platform, Qwest CyberVoice Interconnect, a wholesale voice over IP (VoIP) terminating service that enables service providers to deliver clear, reliable voice calls over Qwest's nationwide broadband Internet network.

Sonus continues to advance its deployments with other carriers. Yesterday, Sonus and Time Warner Telecom announced that Time Warner is now delivering revenue-generating traffic over the Sonus-based infrastructure in eight U.S. markets. Time Warner is initially leveraging the Sonus packet voice solutions to augment its existing Class 5 circuit switches and offload modem-generated Internet traffic from its voice network. Time Warner also plans to use the Sonus infrastructure to deliver traditional local and long-distance services, as well as new voice over IP-based services such as unified communications, single number service, call centers, and more.   

Sonus continued to gain momentum in the market for carrier-class packet voice switching equipment, and was again named the worldwide market share leader. Reports issued by industry research firms Cahners In-Stat, Infonetics Research Group and Synergy Research Group confirmed Sonus' market-leading position for the fourth quarter of 2000 and for the full year 2000.

To provide carriers a wide range of options for deploying enhanced voice and data services, Sonus broadened its Open Services Partner Alliance (OSPA) program. The expanded program, which integrates the best components of previous Sonus and telecom technologies partner programs, offers greater value to both service providers and partners through a new multi-tiered participation structure and the state-of-the-art OSPA Interoperability Lab. Sonus also added eleven new partners to the OSPA, and announced that six other partners had successfully completed interoperability testing, achieving Sonus "Powered" status in the program.

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 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 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' Annual Report on Form 10-K, dated March 28, 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, integration risks relative to its acquisition of telecom technologies, rapid technological and market change and manufacturing and sourcing risks.

INtelligentIP is a registered trademark of Sonus Networks. GSX9000, PSX6000, SGX2000, Open Services Partner Alliance 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.