Company Captures #1 Market Share Position in Key Segments of Next Generation Communications Market

WESTFORD, Mass., March 14, 2007 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, today announced that according to independent research by Synergy Research Group, Sonus has once again achieved market share leadership in key segments of the next generation IP voice market, both for Q4 2006 and for the full year 2006.

“Sonus had a fantastic year, and once again, led the market on a global and regional basis in key segments of the IP voice market. Sonus significantly outpaced the overall market growth with number one positions in the United States and Japan , and an increasingly strong position in Europe ,” said Jeremy Duke, president and CEO, Synergy Research Group. “The breadth of Sonus’ customer base, and the rate at which Sonus-based deployments have scaled, highlight the value that IP voice can deliver to communications providers across the globe.”

In 2006, Sonus outpaced the overall market, which grew 27%. Sonus’ strong performance throughout the year resulted in #1 market share positions for key segments in the worldwide IP voice market, as well as leading positions on a regional basis. In the United States , Sonus continued its market-leading position in the high density gateway market with approximately 34%. In Japan , the Company was once again the dominant market leader in total VoIP equipment and high density gateway market with approximately 49%. In Europe , the Company demonstrated significant momentum tripling its market share from 2005.

“Sonus is focused on executing on a global basis, and the most recent report from Synergy demonstrates that we’re doing so effectively. It’s great to see our recent efforts in Europe have begun to yield very strong results, and that we’re successfully gaining market- and mindshare in this important region,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “2006 was a great year for our Company, and as we look ahead, there are many positive growth drivers that are helping us to carry that momentum 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 the 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, the Company’s potential inability to meet NASDAQ requirements for continued listing, 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 product or 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.

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