Sonus Delivers Industry's First Small Form Factor Solution Combining Media Gateway Services, Session Border Control and Security Services

CHELMSFORD, Mass., August 2, 2006 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today the general availability of a new Network Border Switch (NBS) designed specifically to provide carrier-class IP-peering and security capability to both smaller IP-based voice networks and to less-densely populated regions of larger IP-based networks. This latest product introduction expands the breadth of Sonus' award winning IP Multimedia Subsystem (IMS)-ready architecture, offering new and existing customers more flexibility in their network design and the ability to deploy compact solutions without sacrificing the carrier-class functionality that is the hallmark of Sonus solutions.

“Sonus has always led the innovation curve, delivering sophisticated products that help network operators follow the migration path towards an all-IP network infrastructure,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “Today, network operators have embraced the value of IP and are looking for ways to grow their IP-based networks seamlessly and securely. As our customer base becomes more diverse, we're committed to delivering a broader range of solutions that meet the requirements specific to their size and growth strategies. The latest NBS product does just that, enabling network operators to deploy a carrier class solution that protects the integrity of their networks when connecting via IP to either enterprises or other IP-based networks.”

Unlike traditional peering and security products such as Session Border Controllers (SBCs), Sonus' NBS delivers a unique solution that combines session control, PSTN gateway services and security into a single, high performance, carrier-class system. Sonus' NBS is a purpose-built IP-based solution that allows network operators to leverage the system's sophisticated media handling functionality; extensive IP signaling options that include SIP, SIP-T and H.323; network address and port translation features that protect the privacy of the internal private network topology; session-based firewall functionality; and advanced traffic control features. Supported by Sonus' GSX4000, the industry's first carrier-class compact media gateway, the newly introduced NBS is based on the field-proven technology of Sonus' NBS product line, which has been shipping since 2003.

The smaller form factor NBS enables new customers to enter the market at a lower price point, deploying a solution that can scale seamlessly as demand grows. Because all of Sonus' solutions are standards-based and leverage the distributed principles that are the foundation for IMS, existing Sonus customers can easily integrate the new NBS into their existing networks to support regions that do not require the capacity and density of a more robust solution, while at the same time leveraging existing provisioning, policy and reporting features already deployed in their network. For either new competitive network operators or incumbent network operators that are looking to scale their networks into new geographies, deploying the NBS will result in increased operational and CAPEX efficiencies, expanded revenue opportunities through media transcoding, and the critical signaling and media security functionality that is a prerequisite to ensure the integrity of the network.

“As the IP-based voice market continues to grow, telecom solutions vendors that excel at delivering carrier class and flexible, right-sized solutions are poised for success, ” said Brian Partridge, senior analyst with Yankee Group. “The newest IP peering solution from Sonus will enhance their ability to address one of the more exciting opportunities in the next generation voice market.”

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 the “Risk Factors” section of Sonus' Quarterly Report on Form 10-Q, dated May 8, 2006, filed with the Securities and Exchange Commission, 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 of the Company's financial statements or results, 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 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.