Independent Research Reports Sonus Networks as the Leader Worldwide in High-Growth Areas of Next Generation Communications Industry

Sonus Networks NXTcomm BOOTH #4215

WESTFORD, Mass. and CHICAGO, IL, June 19, 2007 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today at NXTcomm 2007 (Booth#4215), one of North America's largest communications industry trade shows, that according to independent research by Synergy Research Group, Sonus has once again achieved market share leadership in key segments of the next generation IP voice market for Q1 2007.

In Q1 2007, Sonus Networks led the worldwide high density VoIP gateway market with 31.6% market share. In the United States, Sonus led both the total gateway, with approximately 33%,and high density gateway with approximately,42% markets. Sonus continues to garner a strong market share position in Japan, where Sonus is reported as achieving approximately 50% of the total gateway market and a dominating  approximately 67% market share for high density gateways, more than 7x its closest competitor.

"Sonus has established itself as a leader on a global scale, ranking #1 in the US and Japan, and is rapidly establishing leadership in the growing European market," said Jeremy Duke, president and CEO, Synergy Research Group. "Sonus' ability to win network deployments with tier one operators globally, coupled with ramping traffic across its customer base has solidified Sonus' position as one of the premium providers of IP based voice equipment."

"Sonus has been selected by all five of the world's largest network operators and is expanding its presence with other leading operators around the world," said Hassan Ahmed, chairman and CEO, Sonus Networks. "Our ability to deliver networks with unparalleled quality, reliability, and scalability that are secure has enabled us to earn and maintain this coveted position as the #1 provider in key segments of the IP voice industry."

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 the 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, whether the Company will file its required SEC reports by June 26, 2007 and remain listed on the NASDAQ Global Select Market, 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.