Sonus Networks Leads Wireless IP Voice Industry

Sonus-Powered Wireless Networks Now Carry More than 10 Billion Minutes of Voice Traffic Every Month

WESTFORD, Mass. and BARCELONA, Spain, February 12, 2007 - Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today at the 3GSM World Congress in Barcelona, Spain (Booth D46, Hall 2, Level 1) that the Company has surpassed a key milestone in the industry's migration to wireless IP voice. Sonus-based wireless networks worldwide now carry more than 10 billion minutes of voice traffic per month. According to the latest research report entitled, “Packetized Wireless Trunking: 2007 Status Report” by independent research firm iLocus, Sonus carries more than 37% of all wireless packet-based traffic. Sonus' IP Multimedia Subsystem (IMS)-ready solutions currently form the backbone of major wireless networks in the United States and Japan.

“Like their wireline counterparts, wireless network operators are now beginning to embrace IP-based technologies throughout their networks to take advantage of operational savings and to build a foundation for the delivery of enhanced next generation services, and they are turning to Sonus to help realize those benefits,” said Basharat Ashai, Research Manager, iLocus. “Sonus has built some of the most sophisticated IP-based wireless networks in the world, carrying billions of minutes of traffic every month and growing rapidly.”

Sonus' IP Multimedia Subsystem (IMS)-ready architecture for wireless networks delivers significant cost-savings, operating efficiency and the ability to build new revenue streams through the delivery of enhanced end user services. In addition, as the industry moves towards full IMS compliance, Sonus' solutions provide a seamless migration path, enabling wireless network operators to leverage the benefits of a converged network core for the delivery of rich, multimedia services that change the way people communicate.

“As wireless network operators continue to fight for customer acquisition and customer retention, the ability to manage costs and open the doors for new revenue streams becomes increasingly important,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “Even in these early days of the market's development, our wireless customers have saved millions of dollars by deploying a Sonus-based architecture. We anticipate wireless network operators to be a major driver of our business in 2007 and beyond.”

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice over IP (VoIP) infrastructure solutions for wireline and wireless service providers. With its comprehensive IP Multimedia Subsystem (IMS) solution, Sonus addresses the full range of carrier applications, including residential and business voice services, wireless voice and multimedia, trunking and tandem switching, carrier interconnection and enhanced services. Sonus' voice infrastructure solutions are deployed in service provider networks worldwide. Founded in 1997, Sonus is headquartered in Westford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

This release may contain forward-looking statements regarding future events 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 Item 1A “Risk Factors” of Sonus' Quarterly Report on Form 10-Q dated May 8, 2006, 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: the impact of material weaknesses in our disclosure controls and procedures and our internal control over financial reporting on our ability to report our financial results timely and accurately; the unpredictability of our quarterly financial results; risks and uncertainties associated with the Company's announced review of its historical stock option grants and accounting, including any potential impact on the Company's financial statements or results, any tax liabilities or penalties, the Company's inability to timely report with the Securities and Exchange Commission, whether the Nasdaq Listing Council will continue the delisting stay or grant an extension or that the company's securities will remain listed on the NASDAQ Stock Market, potential investigations, regulatory actions or litigation arising out of the review or any restatement; risks associated with our international expansion and growth; consolidation in the telecommunications industry; and potential costs resulting from pending securities litigation against the company. 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.

The product information in this press release is for informational purposes only and is subject to change at Sonus' sole discretion without notice. Sonus has no obligation or commitment to develop or deliver any future release, upgrade, feature, enhancement or function described in this release. The information is provided “AS IS,” with all faults, and without any warranties whatsoever, express or implied, including, but not limited to, warranties of merchantability, performance, or fitness for a particular purpose.

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