WESTFORD, Mass., February 8, 2007 - Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that the NASDAQ Listing and Hearing Review Council (the “Listing Council”) has determined to stay the February 12, 2006 deadline set by the NASDAQ Listing Qualification Panel for the company to become current in its periodic filings with the Securities and Exchange Commission (SEC). Accordingly, the company's stock will remain listed on the NASDAQ Stock Market pending further action by the Listing Council. The Company is working diligently toward the completion of its restated financial statements and the filing of its periodic SEC reports to regain compliance with NASDAQ's listing requirements.

Additionally, the Company announced that it has scheduled a conference call for Wednesday, February 28, 2007, at 4:30 pm Eastern time to discuss its Q4 and 2006 financial results.

Date: Wednesday, February 28, 2007
Time: 4:30 pm Eastern

To listen via telephone:
Dial-in number: (800) 707-1264
International Callers: (415) 537-1824

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 (402) 977-9140. The reservation number for the replay is 21328916. The telephone playback will be available through March 14, 2007.

A replay of the webcast will be also available on the Sonus Networks Investor Relations site through Thursday, February 28, 2008. To access the replay of the webcast, visit www.sonusnet.com, Corporate, Investor Relations.

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 any potential 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 Nasdaq Listing Council will continue the delisting stay or grant an extension or that the company's securities will remain listed on the NASDAQ Stock Market, potential investigations, 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.