Sonus Networks Extends Market Share Lead Worldwide

Infonetics Research Names Sonus Market Share Leader in High Density and Total Gateway Markets

WESTFORD, Mass., May 30, 2007 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that Infonetics Research, a leading independent industry research firm, has named Sonus Networks the market share leader in several segments of the IP-based voice market for Q1 2007 in its "Service Provider Next Generation Voice and IMS Equipment Market Forecast." Sonus leads both the total gateway and high density gateway markets worldwide, as well as in North America.

According to the report, Sonus led the total gateway market with 20% market share worldwide and 36% in North America, double its closest competitor. In the high density gateway market, Sonus led with 26% market share worldwide and 45% in North America, more than triple its closest competitor. In addition, Sonus continued to grow its position in EMEA, increasing its market share over 200% and 250% in the total gateway and high density gateway markets, respectively.

"Sonus holds a commanding lead in market share for both total gateway and high density gateway segments, particularly in North America. In addition, Sonus significantly increased its presence in EMEA," said Stéphane Téral, Principal Analyst, Service Provider Next Gen Voice VoIP, IMS, and FMC, with Infonetics Research. "Sonus continues to be one of the industry’s premiere providers of IP voice solutions, trusted by the world’s largest wireless and wireline network operators."

"Coming off of a record 2006, we're excited to see the momentum continue and the outstanding results for Q1 2007 validated by a respected independent research firm like Infonetics," said Hassan Ahmed, chairman and CEO, Sonus Networks. "More and more network operators around the globe are realizing how Sonus can play a key role in the transformation of their networks, delivering both improved operating leverage and reshaping the end user experience. We're committed to helping our customers reap the benefits of their investment in their Sonus-based networks and maintaining our leadership position in this exciting market."

For a copy of the Infonetics Research report, please contact Larry Howard at 408.583.3335 or larry@infonetics.com.

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.