Market Leader Provides Sophisticated Operational Support for Multimedia Services

CHELMSFORD, Mass., August 16, 2006 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today the latest release of its carrier class billing platform, enabling network operators to further streamline the integration of next generation applications with existing Operational Support Systems (OSS). By leveraging the Sonus Insight Management System™, service providers can support the rapid integration of new multimedia services into existing billing platforms. Sonus' billing mediation solution, the DataStream Integrator (DSI), effectively mediates and correlates billing records, whether generated from Sonus-based platforms or from third party application platforms, and incorporates the information into traditional as well as next generation billing systems.

The latest release of the billing solution includes the availability of a new streaming billing functionality for the GSX4000™ Open Services Switch. This feature eliminates the need for local storage of billing records by allowing multiple GSX4000s to stream records to a single, centralized DSI Billing System rather then dedicated local servers, driving down the cost of the overall network and maintaining the benefits of a smaller form factor the GSX4000 was designed to address.

“One of the primary benefits of a highly distributed architecture is the ability to rapidly and seamlessly introduce new services into the network, but those new services are only valuable to the network operator if the infrastructure is in place to properly bill for them,” said Vikram Saksena, vice president, chief architect, Sonus Networks. “With the number of new features and services coming to market, billing mediation and managing call flow becomes more complicated. The Sonus DSI was built from the ground up to support distributed SIP-based networks and enables carriers to overcome a key barrier to entry by allowing new applications to interface with legacy billing solutions.”

Carrying over 22 billion minutes of IP-based voice traffic per month, Sonus solutions are deployed in many of the largest IP-based wireless and wireline voice networks around the world. Sonus provides a complete IP multimedia subsystem (IMS)-ready architecture for carriers looking to transform the communications landscape through the introduction of enhanced next generation voice and data services.

The latest version of Sonus' billing platform is now shipping and generally available.

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.