Sonus Networks Continues To Expand Cable MSO Base In Europe

WESTFORD, Mass., July 11, 2008 – Sonus Networks, Inc. (Nasdaq: SONS), a market leader in IP communications infrastructure, announced today that PTV Telecom, a provider of voice, video and data over cable, has chosen Sonus Networks to replace its existing infrastructure with a PacketCable-compliant next generation network to offer enhanced business and residential services to customers in five major cities across Spain.

PTV Telecom, a fast growing cable service provider is one of the few operators in Spain with a wholly owned telecommunications network, which enables the company to remain at the forefront of the market in terms of services and value. PTV Telecom offers triple play services to its cable service subscribers, as well as original local programming. PTV Telecom's move to a Sonus IP-based network will facilitate future subscriber base growth, deliver multi-play services and drive expansion into the enterprise market via IP trunks and data services.

"Sonus Networks was the only company to offer us the technology to get our services to market quickly," commented Manuel Ib????ez, operations and projects director at PTV Telecom. "We need to differentiate ourselves from our competition by offering increased reliability and enhanced services. The heritage and experience Sonus brings along with its advanced technology offerings gives us the platform from which to launch our next phase of growth."

Sonus is migrating PTV Telecom's entire legacy network, which spans five cities across Spain - Madrid, Cordoba, Valencia, Seville and Malaga. The Sonus components that will be implemented include the Sonus ASX, Sonus Insight Element Management System ^TM (EMS), Sonus PSX^TM, Sonus GSX9000^TM media gateway and Network Border Switch ^TM.

"Sonus is pleased to be a part of PTV Telecom's expansion plans," commented Tony Morrish, vice president, EMEA at Sonus Networks. "Sonus is growing across EMEA, and this win demonstrates both our commitment to serving and supporting voice over IP customers across the entire region, and our progress in helping cable customers evolve to next generation solutions. Spain has a mature communications market, and the Sonus-based network will enable PTV Telecom find new business opportunities across the country."

About Sonus Networks

Sonus Networks, Inc. is a market leader in IP communications infrastructure 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 for the period ended March 31, 2008, 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 restatement of its historical stock option granting practices and accounting including regulatory actions or litigation; risks associated with our international expansion and growth; consolidation in the telecommunications industry; and potential costs resulting from pending securities and patent 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, except as required by law.

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.