United States Department of Agriculture Rural Development Utilities Committee Adds Sonus' Core Trunking Solutions to List of Accepted Materials

CHELMSFORD, Mass., November 15, 2006 - Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that the Technical Standards Committee “A" (Telecommunications) of the Rural Utilities Service/Rural Development Utilities Program (RUS/RDUP), a division of the United States Department of Agriculture, has granted “RUS/RDUP Acceptance" status to key elements of Sonus' industry leading IMS-ready architecture, including the GSX™9000 Open Services Switch, PSX™ Call Routing Server, SGX™ Signaling Gateway, and the Sonus Insight™ Element Management System. The RUS/RDUP acceptance helps Sonus reach a broader market of network operators by enabling third-party resellers to sell Sonus' solutions to RUS-funded service providers.

"RUS/RDUP acceptance for Sonus' solutions provides rural carriers with the flexibility to invest funds in the industry's market-leading, field proven IMS-ready core infrastructure," said Steve Edwards, Chief Marketing Officer, Sonus Networks. “In addition, the RUS/RDUP acceptance is a critical step for our Company, as it helps to expand our strategic reseller relationships to focus on addressing the rural telecommunications market in the United States."

RUS/RDUP provides funding to Rural Telephone Companies for telecommunications initiatives in rural communities throughout the United States. These initiatives include financing construction, procurement of equipment, and enhancements to networks.

“Nowhere is the promise of IP-based voice communications as profound as it is in rural America," said Jim Kohlenberger, spokesperson for the Internet Voice Campaign (IVC), an alliance of the country's leading Internet voice providers designed to raise awareness and to help educate consumers about the benefits of voice services delivered over IP. Sonus Networks is one of the founding members of the IVC, which is part of the VON Coalition. “In addition to helping families in these areas stay connected across geographies, the proliferation of VoIP into rural areas creates new economic opportunities by cost-effectively bridging the distance between urban and rural America."

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 Chelmsford, 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, the Company's potential inability to meet NASDAQ requirements for continued listing, 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. All other company and product names may be trademarks of the respective companies with which they are associated.