SONUS-BASED NETWORKS CONTINUE TO RAMP IP VOICE TRAFFIC; COMPANY EXTENDS LEAD IN NEXT GENERATION COMMUNICATIONS MARKET

Strong Growth in 2006 Solidifies Sonus’ #1 Market Share Position

WESTFORD, Mass.  , April 11, 2007 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that according to a report entitled, “VoIP Minutes and Subscribers: 4Q06 Update,” issued by iLocus, approximately 38% of all long distance IP-based voice traffic is carried over Sonus Networks’ IP Multimedia Subsystem (IMS)-ready networks. The percentage of traffic being carried over Sonus’ IMS-based networks has increased steadily in 2006, as an increasing number of major network operators have migrated traffic onto their Sonus-based platform. 

“Sonus’ leadership in terms of minutes of traffic carried each month is a huge testament to the strength of our products and the quality of our customer service and support team,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “Our ability to deploy large-scale, carrier class networks of this magnitude is unique in the industry and provides us with the credibility that is required to be the chosen partner of the world’s biggest network operators.”

Sonus Networks currently carries more than 33 billion minutes of IP-based voice traffic every month, up approximately 75% from the same period in 2006. The iLocus report recognized that Sonus leads both the national and international long distance market with 39% and approximately 26% of voice traffic respectively. Carrying 38% of total long distance voice traffic, Sonus carries nearly 4 out of 10 IP-based voice minutes.

“Throughout 2006, we saw a number of large incumbent operators significantly grow their IP-based voice networks to support the migration of significant amounts of traffic off of legacy platforms,” said Jahangir Raina, Director, iLocus. “With a strong presence in both the early adopter networks and more recently, major deployments with tier one operators, Sonus has had a very successful year growing their market leading position.”

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, whetherthe 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.