Expanded Research and Development Facility to Lead Development of Sonus' Advanced Wireless Solutions

WESTFORD, Mass., January 8, 2007 - Sonus Networks (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that the Company has opened a second facility in Bangalore, Karnataka, India. With products deployed in 34 countries around the world, Sonus Networks is the global market share leader in key segments of the carrier voice over IP market, according to independent industry research organizations Infonetics and Synergy Research Group. The new facility will help the Company service its global customer base and expand its research and development capabilities.

Sonus opened its first Bangalore facility in March 2005. The new regional support and research and development center increases Sonus' ability to provide support to its expanding customer base throughout Asia-Pacific region and to deliver forward-looking, innovative products that help network operators around the world realize new benefits from their investment in IP-based networks. The new Bangalore facility will be dedicated to the research and development of next generation wireless solutions, including advancements in its IP Multimedia Subsystem (IMS) solutions.

“Our Bangalore team has been instrumental in the success of the Company's global strategy over the past year. By expanding our presence in India, we are aligning our resources and leveraging the region's deep pool of expertise to execute on our technological vision and to deliver the advanced solutions that will define how networks are built in the future, particularly in the wireless space,” said Chuba Udokwu, vice president, worldwide engineering, Sonus Networks. “Our Bangalore center is demonstrative of what sets Sonus apart in this dynamic industry: a commitment to delivering the products and services that help network operators stay ahead of the competition and servicing our customers with seasoned industry professionals.”

“One reason for Sonus' success on a global basis has been its ability to identify and address unique geographic requirements with products and solutions tailored to specific market demands, and to provide network operators with responsive, quality support,” said Jeremy Duke, president and CEO, Synergy Research Group, analyst firm. “By expanding its presence in India, Sonus is optimizing a rich talent pool of highly skilled engineers to keep the Company at the forefront of innovation.”

“We are extremely proud that the center has met with such a positive response from our customers and the local community. We've met or exceeded the goals set for the center, and are pleased with the continuing level of interest from highly-qualified job applicants,” said Shailin Sehgal, Managing Director of Sonus Bangalore.

The new 9,500 square foot Bangalore center complements Sonus' existing engineering development and customer support centers in India, the United States and the United Kingdom, its customer support center in Japan, and operations centers in key markets around the world.

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.

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.