Industry Leader Reports Strong Quarterly Sequential Revenue Growth and Profitability

Company to Host Conference Call Today, Thursday, March 6th at 9:00 a.m. Eastern Time

WESTFORD, Mass., March 6, 2008 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider IP-voice infrastructure solutions, today reported that it has filed its Annual Report on Form 10-K for the fiscal year 2007 with the Securities and Exchange Commission (SEC). The full audited financial results reported today are consistent with the previously reported preliminary results for the quarter and year ended December 31, 2007.

"I am pleased to have our Form 10-K now on file with the SEC. We are disappointed in the delay in filing our financial statements and will continue to drive progress to improve our financial reporting process. This delay does not detract from our strong sequential revenue growth and improved profitability for the fourth quarter of 2007," said Hassan Ahmed, chairman, president and CEO. "In the second half of 2007, we re-established momentum in our business, ending the fourth quarter with orders that significantly exceed revenue for the quarter. Our 2007 annual revenue growth again exceeded industry analysts' assessments of the overall market growth for 2007, demonstrating that Sonus is continuing to gain market share. I am confident in our ability to continue to outpace the market growth as we move into 2008 and beyond."

Sonus Networks has scheduled a brief conference call for today, Thursday, March 6, 2008, at 9:00 a.m. EST to review its full financial results for Q4 and fiscal year 2007.

Date: Thursday, March 6, 2008
Time: 9:00 a.m. EST

To listen via telephone

Dial-in number: 800 913 8744
International Callers: +1 212 231 2901

To listen via the Internet

Sonus will host a live webcast of the conference call. To access the webcast, visit www.sonusnet.com, Corporate, Investor Relations.

Replay

A telephone playback of the call will be available following the conference and can be accessed by calling 800 633 8284, or for international callers, please call +1 402 977 9140. The reservation number for the replay is 21377989. The telephone playback will be available through March 20, 2008.

A replay of the webcast will be also available on the Sonus Networks Investor Relations site. To access the replay of the webcast, visit www.sonusnet.com, Corporate, Investor Relations.

Note

The Company's GAAP financials for the fourth quarter and fiscal 2007 are attached to this press release. Additional information regarding Sonus' financial results, including the Company's Annual Report on Form 10-K for fiscal year 2007 and a reconciliation of GAAP to Non-GAAP performance, is available on the Sonus Investor Relations Website at http://www.sonusnet.com under Financial Documents. Due to the late notification of today's conference call, the Company will file prepared remarks from today's brief conference call on Form 8-K with the SEC.

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 contains forward-looking statements regarding future events that involve risks and uncertainties, including statements relating to Sonus' expected business income growth. 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' Annual Report on Form 10-K for the year ended December 31, 2007, 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 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.