KDDI Global Brings High Quality Services to the Global Wholesale Market

WESTFORD, Mass., July 30, 2009 – Sonus Networks, Inc. (Nasdaq: SONS), providing network transformation through IP communications technology, today announced that KDDI Global, part of KDDI Corporation a global tier 1 telecommunications wholesale carriers is using a Sonus IP-based network to support the expansion of its business into the US, EMEA and across ASIA.

The network, operated by KDDI Global, is now carrying approximately 100 million IP voice minutes per month, serving four cities around the world, in Los Angeles, London, Osaka and Tokyo.

The next generation IP-based network enables greater capacity and efficiency leveraging the platform’s centralized routing, diverse media support and secure border control for cost effective IP peering. The Sonus Global Services team worked alongside KDDI Global to implement a SIP core to manage the legacy TDM and new IP voice traffic on the same network.

“The Sonus based network has proven to be a robust, reliable and scalable solution for KDDI in Japan for three years,” commented Daichi Nozaki, president and COO at KDDI Global. “The professional services team at Sonus helped us to get the network into service and carry traffic within a matter of months. We expect our business to grow over the next five years and we know the Sonus network can evolve to meet our customer needs.”

KDDI Corporation has been a Sonus customer since 2005 and within Japan has implemented the Sonus GSX9000(TM) Media Gateway, the PSX(TM) policy routing server and the Sonus Insight Element Management System. Leveraging the flexible, robust Session Initiation Protocol (SIP), KDDI offers on-net calling services, as well as IP-to-PSTN and PSTN-to-IP calling, on the Sonus infrastructure.

“Sonus and KDDI Corporation have enjoyed a successful relationship for over four years,” commented Guru Pai, senior vice president and general manager at Sonus Networks. “KDDI Global have taken advantage of the value to be gained from Sonus technology, and working closely with Sonus professional services to prepare for its network expansion. We are proud that our solutions have proven to be a robust, reliable and scalable platform for KDDI across the world.”

About KDDI Global

KDDI Global, also known as KGL, is the formation of a KDDI America majority-owned strategic initiative between KDDI America and Asia Access Telecom. With KDDI America’s financial resources and AAT’s operational strengths, KGL will quickly become a global Tier 1 telecommunications carrier, offering quality services at competitive prices in the wholesale telecommunications market.

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 Quarterly Report on Form 10-Q for the quarter ended March 31, 2009. Risk factors include among others: the unpredictability of our quarterly financial results; risks and uncertainties associated with the Company's previous restatement of its historical stock option granting practices and accounting including regulatory actions; actions that may be taken by significant shareholders; risks associated with our international expansion; and the impact the current global financial market conditions may have on the telecommunications industry. 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, except as required by law.

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:

Sonus Media Relations:
Lucy Millington
978-614-8240
lmillington@sonusnet.com

Racepoint Group for Sonus
Shannon Breen/Katie Traut
781-487-4600
sonus@racepointgroup.com