Fixed-Mobile Convergence, Presence, and Personalization Driving the Next Wave of Innovation

WESTFORD, Mass.  , March 21, 2007 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that the Company will be exhibiting at CTIA WIRELESS 2007® in Orlando, Florida, March 27-29, 2007. The Company will be showcasing a suite of next generation voice and multimedia applications built on Sonus’ industry-leading IP Multimedia Subsystem (IMS)-ready architecture, designed to enable network operators to create new revenue streams and empower users with new methods of communications. Sonus is the market share leader in wireless IP-based voice networks according to iLocus Research.

“Wireless network operators are aggressively pursuing new ways to create revenue streams and improve the consumer experience,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “Fixed-Mobile Convergence (FMC) is a great example of the type of application that network operators see as a way to add value to their customers’ communication experience, while at the same time improving their own operating efficiencies. We’re excited to show the industry how Sonus is working to make this application, and other services that embrace the principles of personalization, presence and service mobility, a reality at this year’s CTIA Conference.”

Sonus will demonstrate a number of wireless applications in its exhibit, located at Booth 4151. Supported by the Sonus IMS-ready architecture and built with Sonus' IMS application development tools, including the Sonus IMX™ Multimedia Application Platform, these new wireless applications will illustrate how a Sonus-based network can help network operators globally deliver the types of applications and services that address the lifestyle demands of today’s mobile users.

CTIA WIRELESS is the world’s largest technology event dedicated exclusively to wireless, broadband convergence and mobile computing technologies, covering the entire industry from network infrastructure to microprocessors to applications to content to end-user hardware. The CTIA WIRELESS 2007 convention is the world's largest convergence marketplace with tens of thousands of attendees, over 400,000 square feet of exhibits, 20% international participation from over 100 countries, and represents a $500 billion global industry with 2.3 billion subscribers worldwide.

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’sfinancial 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 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.