Sonus NetScore Offers Customers Improved Network Performance Through Real Time Network Analysis and Reporting

New Sonus NetScore™ CDR Analyzer Gives Network Operators the Power To Improve Network Performance And Efficiency

WESTFORD, Mass., August 20, 2009 – Sonus Networks Inc. (Nasdaq: SONS), providing network transformation through IP communications technology, today announced the availability of Sonus NetScore™, a new network performance analyzer that enables customers to increase operational efficiencies, reduce infrastructure costs and maximize return on investment. Sonus NetScore™ uses advanced analytics to determine voice network performance and identify key performance indicators (KPIs) to provide consistent and meaningful data for understanding network quality, performance and reliability through call detail record (CDR) analysis.

Based on years of voice over IP network design and optimization expertise, Sonus has developed Sonus NetScore™ to provide an intelligent analysis of every call, offering a level of granularity previously unavailable. This enables network operators to better manage fluctuating call volumes, identify specific issues to protect quality of service for their subscribers and help to justify additional capacity investment to meet business needs.

“Voice networks are dynamic by nature. When making the strategic migration from TDM to IP, the ability to provide business managers with real time data about network performance becomes critical to maintaining maximum availability of the network as well as justification for continued investment for efficient growth,” said Wassim Matragi, vice president, network technologies for Sonus Networks’ global services group. “We have been helping customers to maximize their return on investments through Sonus professional services for many years, and now with Sonus NetScore, we are providing a platform to create and monitor these critical KPIs in real time.”

The Sonus NetScore™CDR analyzer provides a real time analysis of call detail records from across the network giving network operators a live view into the status, efficiency and available capacity of their core business asset. Key performance indicators such as answer seizure, answer bid, network effectiveness and disconnect category ratios are presented in easy to read graphical reports that can be analyzed against quality of service metrics, gateway to gateway IP packet loss and detailed gateway/trunk group data to give the most comprehensive set of voice network data and analysis available to Sonus customers today.

“In today’s environment, network operators need to understand current network performance before making additional investments,” commented Elisabeth Rainge, director, NGN operations at IDC. “Maintaining call quality and the highest levels of customer service are dependent on the overall efficiency of the network. To stay in step with corporate goals, the network teams must develop and maintain metrics on network health as a foundation on which to build the business case to increase network capacity.”

For more information on system requirements and platform details visit www.sonusnet.com/netscore.

About Sonus Networks

Sonus Networks Inc., providing network transformation through IP communications technology, is leading the evolution of communications networks to support the multi-device demands of today’s digital lifestyle. Sonus solutions and services enable fixed, mobile and cable operators to gain session awareness and deliver multi-media capabilities essential to adding value and expanding their customer and subscriber base. Through standards based interoperable solutions and services, Sonus extends the investments made in traditional networks by enabling operators to seamlessly migrate to next generation technology and deliver the secure, reliable, scalable and cost-effective network needed to grow their business. For more information visit 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.For a discussion of the risks and uncertainties which could cause actual results to differ from those contained in the forward-looking statements, see “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2008 and subsequent Quarterly Reports on Form 10-Q.

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.

For more information, please contact:

Lucy Millington
T: 978-614-8240
lmillington@sonusnet.com

Shannon Breen, Racepoint Group
T: 781-487-4607
sbreen@racepointgroup.com