Sonus Networks Honored By AT&T As Outstanding Supplier

WESTFORD, Mass., June 11, 2007 – Commitment to excellence over the past year has earned Sonus Networks (Nasdaq: SONS) recognition as an outstanding supplier to AT&T Inc. (NYSE:T), one of the world’s leading data, voice, wireless and Internet services providers.

"We are proud of our long-standing tradition of providing unparalleled products and services to our business and residential customers," said Maureen Merkle, President, AT&T Procurement. "We're successful on that front in large part thanks to suppliers partners like Sonus Networks that consistently go above and beyond the call of duty."

Sonus Networks received one of 39 supplier recognition awards for its work in helping AT&T deliver outstanding service to its customers during the past year. Sonus Networks was recognized for its contributions in the category of Teamwork.

"Sonus is honored to have been selected as one of AT&T's most respected suppliers. Customer excellence is what motivates the team at Sonus and we have been contributing to AT&T's next-generation communications infrastructure with that same spirit," said Hassan Ahmed, chairman and CEO, Sonus Networks. "Our primary goal is our customers' success and helping them achieve their business objectives. This award by AT&T demonstrates our commitment and ongoing focus on delivering not only networks that are reshaping communications, but being a great partner to our customers.

As part of its annual supplier recognition program, AT&T took out a half-page ad in the June 5, 2007, edition of the Wall Street Journal to publicly thank the selected companies.

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.