Company Introduces Innovative New Platform for Delivering Local Calling Features and Enhanced Security

WESTFORD, Mass., August 20, 2007 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today a new version of its enterprise and residential voice services software platform. The new platform, called Access 7.0, brings a broad array of innovative and traditional voice features to telephone operators that will enable the delivery of enterprise and residential IP-voice services to customers, regardless of the last-mile connection. The latest release of Sonus' award-winning IP Multimedia Subsystem (IMS) network architecture allows local communications providers to deploy robust, cost-effective voice networks and increase their overall network security. Sonus’ vision of next-generation communications entails the real-time delivery of advanced voice and multimedia services, while optimizing the network to provide required safety and traditional call features.

"Sonus' strength is built on listening to customers and understanding the dynamics evolving in the communications market," said Hassan Ahmed, chairman, president and CEO. "Sonus has embraced the rich ways that communications have grown over the last decade, driven by the increasing demand for constant connectivity by consumers and professionals around the globe. We are providing operators globally with the strategic assets not only to deliver traditional call features, but also to deliver real-time cutting-edge services."

As operators increasingly leverage their IP network to deliver unified communications, regardless of the last-mile connection, Sonus continues to deliver innovative new products, programs, and capabilities to help customers transform their networks to align with the new communications paradigm. In addition, the Sonus platform is designed to support current business models and help network operators reach the broadest possible audience.

"The latest release of the Sonus platform provides value to network operators in two principle ways. On the one hand, it enables network operators to rollout ubiquitous next generation voice service that's transparent to the end user, allowing operators to reap the operational benefits of IP voice without impacting the consumer experience, thereby speeding adoption," said Vikram Saksena, Chief Technology Officer, Sonus Networks. "The more important opportunity, however, is to reshape the way consumers think about and use communications tools. The latest release of the Sonus platform delivers to the world's network operators a truly carrier-class solution for the wholesale replacement of legacy primary line infrastructure."

Sonus Access 7.0 Platform

The latest release of Sonus' Access Software is a platform that leverages Sonus' IP multimedia subsystem (IMS) architecture allowing operators to deliver a superior voice telephony experience via IP. Sonus' industry-first approach greatly reduces deployment time, improves overall security and offers network operators a service that delivers greater business agility. Further, Access 7.0, incorporates IMS/TISPAN-compliant access technologies and integrates with third-party or traditional last-mile connections.

"Sonus already validated the strategy of this approach with earlier access wins in Europe, and now with the adoption of new standards-based features, broadens the appeal of the solution to other tier one operators," said Teresa Mastrangelo, Principle analyst with Broadbandtrends.com.

Reflecting Sonus' experiences deploying the world's largest IP voice networks, Access 7.0 is closely aligned with real operator requirements. Building on the expertise that resulted from Sonus' first IMS customer projects, the access platform serves as a base for the integration of services, including basic voice services and any customization efforts to take into account specific needs of the service provider. Reusing last-mile connection from the TDM framework saves network operators time and effort during the service integration phase.

For more information on Sonus' IMS-based architecture, please visit www.sonusnetworks.com.

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 for the period ended March 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; whether the Company will remain listed on the NASDAQ Global Select Market; 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.

The information in this press release is for informational purposes only and is subject to change at Sonus' sole discretion without notice. Sonus has no obligation or commitment to develop or deliver any future release, upgrade, feature, enhancement or function described in this release. The information is provided "AS IS," with all faults, and without any warranties whatsoever, express or implied, including, but not limited to, warranties of merchantability, performance, or fitness for a particular purpose.

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