Sonus Networks Ranked Global Leader for IP-Voice Infrastructure

Industry Analysts Confirm Market Leader Grew Ahead of Competition In the First Quarter of 2008

Westford, MA., June 16, 2008 – Sonus Networks (Nasdaq: SONS), a market leader in IP communications infrastructure, today announced that it led the global media gateway market in Q1 2008 according to figures from Synergy Research Group, a leading independent industry analyst firm, and Infonetics, an international market research and consulting firm specializing in data networking and telecom. Following its strong leadership position during 2007, according to the recent analysts’ reports, Sonus holds the number one position for the global market in VoIP media gateways, high density VoIP media gateways and total media gateways overall.

In the quarterly report entitled "Service Provider VoIP and IMS Equipment Providers – Q1 2008," Infonetics named Sonus Networks as the market leader in the global high density media gateway sector, and the global media gateway sector overall.

"As Sonus enters its second decade in the IP-voice market, this industry leader continues to expand its market position and leadership," commented Stéphane Téral, principal analyst, service provider next generation voice and mobile core with Infonetics Research. "The carrier IP-voice equipment market remains healthy, driven by the long term migration of carriers to packet telephony. The media gateway sector in particular experienced year over year growth, due to the migration by an increased number of large operators to an IP foundation for their voice communications. Sonus is leading this evolution with innovative solutions that are designed for the most demanding networks."

Confirming that Sonus continues to lead the market into 2008, the Synergy Research Group also named Sonus as the Q1 2008 global leader in the total VoIP media gateway sector and the global high density VoIP media gateway sector with 29% market share, in their quarterly update "Q1 2008 Service Provider VoIP/IMS Market Shares".

"The last decade has seen tremendous change with the disruption of IP Voice in both Enterprise and Service Provider Networks. With this change we have seen a lot of VoIP companies come and go," says Jeremy Duke, President & CEO, Synergy Research Group, "but Sonus remains the standout vendor that has delivered on its promises and has ascended as a tier 1 market leader, which continues to speak to their market leadership today."

"Over the last ten years, we are proud that Sonus has led the migration to IP-voice by major tier 1 operators. With only 20% of the voice traffic running on IP platforms, the opportunity remains robust for Sonus to expand its leadership and continue to transform the world's communications," said Hassan Ahmed, chairman at Sonus Networks. "It is testimony to Sonus' ability to meet customer needs and thus retain our leadership position."

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.