Major Japanese Carrier Is First Customer With NextGen and Sonus for Nationwide Deployment of IP Trunking And Switching Solution

WESTFORD, Mass., July 29, 2009 –Sonus Networks Inc. (Nasdaq: SONS), providing network transformation through IP communications technology, today announced that it has entered into a distributor agreement with NextGen Inc., to offer and support the full portfolio of Sonus Networks carrier-grade IP communications solutions to the Japanese market.

The relationship has already proven successful with a major Japanese carrier choosing NextGen to undertake the nationwide deployment of its IP trunking and switching network. Using a Sonus IMS-based next generation network, this deployment will include the Sonus GSX(TM) 9000 media gateway, the Sonus PSX(TM) centralized routing and policy management server and the Sonus SGX(TM) signaling gateway.

The contract was awarded following a series of rigorous evaluations by the carrier, which included solutions from local and global IP network vendors. The Japanese carrier stated that it was the proven robustness, reliability and scalability of the Sonus solutions, combined with the SIP/VoIP implementation expertise of NextGen that led to the contract being given to NextGen with Sonus Networks.

"We are pleased that NextGen has chosen to offer the Sonus portfolio to customers in Japan, and has already been successful,” commented Guru Pai, senior vice president and general manager at Sonus Networks. “Sonus has an established presence in Japan, supporting several major carrier networks today. This relationship with NextGen will extend the opportunity for Sonus across the country."

With the distributor agreement with Sonus Networks and the construction of the large-scale system using Sonus solutions, NextGen plans to further enhance its SIP/VoIP portfolio and to continue providing solutions that meet demanding needs in the carrier market.

About NextGen, Inc.

Since the dawn of IP telephone services in Japan, NextGen, Inc. has been providing SIP/VoIP solutions in the carrier market where even an instantaneous service unavailability is unacceptable. It has rich experiences in construction/deployment of a large-scale IP Centrex for carriers and developing/providing a solution for interconnecting IP telephones. NextGen has also started a VoIP security business to protect against potential security risks that accompany the spread of NGN, further enriching its experiences as a leading NGN solution service provider.

About Sonus Networks, Inc.

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.

For more information, please contact:

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

Media Relations - NextGen Inc.
Sumita, Business Planning
03-3234-6855
ir@nextgen.co.jp

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.

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