Industry leader establishes a research and development STPI unit in India providing support to its operations worldwide

BANGALORE, INDIA - March 2, 2005 - Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure today announced the opening of a software development and regional support center in Bangalore, Karnataka. Sonus Networks India Pvt. Ltd. will concentrate on the development of VoIP applications, specifically, software design and quality assurance services in support of Sonus' product portfolio.

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The establishment of Sonus' center in India represents another phase in the company's commitment to providing VoIP applications and services to customers around the globe. During the last 12 months, Sonus has significantly broadened its worldwide presence to support increasing market demand. The establishment of Sonus' new engineering development center strengthens Sonus' presence in the region, providing geographically localized focus to its customer base and benefiting its multi-national customers.

Sonus' expansion in India will extend its current engineering development and customer support centers in the United States and the United Kingdom, and complements its customer support center in Japan. Reports from industry research firm Infonetics Research showed that the worldwide market for VoIP technologies increased by 69% during 2004. According to industry statistics on teledensity, a measure of the number of telephone lines per 100 of population, India had a teledensity of nearly 9% at the end of 2004, with plans to increase to 20% by 2008.

"The Internet and telecommunications market is developing rapidly. We believe that India is well poised for leadership in emerging next-generation technologies such as VoIP," said Bert Notini, president and COO of Sonus Networks. "By expanding our presence in this region, we are adding engineering capabilities to support the increasing demand we are seeing from our customers for rapid product development and global support. Our Bangalore development center allows us to draw upon a highly-skilled workforce to provide advanced VoIP solutions to regional and global service providers."

"The opening of the Sonus R&D Center in Bangalore truly exemplifies our commitment to expanding our presence in the Asia Pacific region," commented Simon Naylor, Vice President Asia Pacific of Sonus Networks. "It also places us in close proximity to our customers, enabling us to better understand and therefore tailor solutions that meet our customers' needs. This is indeed a significant milestone for Sonus Networks."

"This development and support center will enable us to continue our momentum in the VoIP market and build on our important presence in India," said Shailin Sehgal, managing director Sonus-India. "We have put together a team of highly qualified specialists who have extensive experience in designing VoIP related telecom products, and we are rapidly expanding this team over the year."

A spokesperson from India's Ministry of Communication & Information Technology, Mr B.V. Naidu, Director of the Software Technology Parks of India said, “We welcome high end technology companies like Sonus Networks to Bangalore. The state-of-art technology that is being developed by Sonus Networks will not only help globally, but will also strengthen and add value to Bangalore's premiere position as the fourth largest technology region in 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 Open Services ArchitectureTM (OSA), Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking and tandem switching, residential and business access, network border switching and enhanced services. Sonus' voice infrastructure solutions, including media gateways, softswitches and network management systems, are deployed in service provider networks worldwide. Sonus, founded in 1997, is headquartered in Chelmsford, 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 the "Risk Factors" section of Sonus' Annual Report on Form 10-K/A dated July 28, 2004 and filed with the SEC, and the "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated November 9, 2004 and filed with the SEC, which identify important risk factors that could cause actual results to differ from those contained in the forward-looking statements. In addition, 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. Open Services Architecture, GSX9000, Insignus and Sonus Insight are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.