Sonus Networks Brings IP Applications that Empower the Next-Generation to 3GSM World Congress

Sonus Networks to Deliver Advanced Multimedia Applications for Mobile Consumers

WESTFORD, Mass., February 8, 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 the 3GSM World Congress in Barcelona, Spain, February 11-15, 2007. The Company will be demonstrating how its advanced IP applications will provide today's mobile user with the ability to customize voice and multimedia applications to meet the demands of their lifestyle. Additionally, Sonus will highlight how its award-winning IP Multimedia Subsystem (IMS)-based architecture helps network operators create revenue-generating opportunities and support a seamless migration path to full IMS compliance. Operators can then leverage the benefits of emerging high speed mobile broadband technologies, such as High Speed Packet Access (HSPA), to deliver truly unique services and applications.

&“Sonus' solutions are deployed in networks around the world by network operators that are eager to begin unleashing the power of IP-based applications and services,” said Steve Edwards, chief marketing officer, Sonus Networks. “Consumers today are demanding the ability to create customized voice and multimedia applications, giving new life to traditional services. As a leader in the IP-voice market, Sonus is making it possible for the world's most innovative wireless service providers to offer exciting new wireless services.”

Sonus will demonstrate a number of wireless applications in its exhibit, located at Booth D46 in Hall 2, Level 4. 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 address the lifestyle demands of today's mobile users.

The 3GSM World Congress is the world's premier mobile event, combining the world's largest exhibition for the mobile industry with a cutting edge congress featuring the most prominent Chief Executives representing mobile operators, vendors and content owners from across the world. More information on the 3GSM World Congress can be found at http://3gsmworldcongress.com.

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, 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.