SONUS NETWORKS' ADVANCED APPLICATIONS HIGHLIGHT NEW REVENUE OPPORTUNITIES FOR MOBILE NETWORK OPERATORS THAT EMBRACE IMS

Sonus Demonstrates IMS-Ready Mobile Applications Today at 3GSM

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 is showcasing a suite of applications designed to highlight the potential of IP Multimedia Subsystem (IMS)-ready applications to reshape how mobile service subscribers communicate.

The suite of applications that Sonus is demonstrating encapsulates new trends in communications, such as consumer demand for increased personalization and customization. These applications can be delivered today over a Sonus IP Multimedia Subsystem (IMS)-ready architecture and built with Sonus' IMS application development tools, including the Sonus IMX™ Multimedia Application Platform.

“The applications we've designed are meant to open mobile operators' imaginations to rethink what's possible in this new age of communications. The strength of the Sonus platform is that it encourages innovation by making applications easier to build and deploy,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “This benefit is especially exciting when you look down the road and see the new wireless technologies that bring high-speed broadband all the way to the handset. At that point, the opportunities to really reshape how people use their phones change dramatically.”

This year at the 3GSM World Congress, Sonus will be demonstrating:

• Parental Controls: An IMX-based application that allows parents to use a Web portal to define and enforce the policy of how their children's cell phones are used, including restricting calls to and from specific numbers, setting the time-of-day the phone can be used, minutes used, etc.
• A “WebWalls” Restaurant Guide: An interactive application that allows users with mobile phones to use a cell phone to interact with an online restaurant guide displayed on a plasma monitor. Restaurant information, such as phone number and location, can then be sent to the mobile handset via Short Messaging Service (SMS).
• A “WebWalls” Properties and Housing Guide: An interactive application that allows users with mobile phones to use a cell phone to interact with Web-connected advertisements for residential and business properties, using a cell phone to direct virtual tours, scan through listings, or contact the listing agent.
• Call Blast: A call feature that allows non-commercial organizations to contact communities of interest. This type of application can be used in a variety of ways, from emergency situations to alert impacted areas of upcoming weather alerts to school administrators informing parents of “snow days”.
• Click-to-Dial Infrastructure: A set of capabilities that enable Web-based services with click-to-dial capabilities. These capabilities could be used by Web merchants to connect buyer and seller without needing to reveal either party's phone numbers.

“The next phase of the battle for subscribers among service providers will be less about price, and more about the ability to match users with the right suite of services,” said Brian Partridge, senior analyst with Yankee Group. “Services that bring personalization to a new level and increase users' ability to flexibly manage their communication portfolio are more and more in demand and Sonus has helped to advance that agenda by delivering an architecture that promotes rapid innovation.”

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.

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