Sonus Networks Delivers MobilEnterprise FMC Solution to Help Operators Offer Cost Effective Services to Mobile Enterprise Customers

Advanced Session Control Technology From Sonus Offers Enterprises Enhanced Capabilities, Improved Coverage and Reduced Network Congestion

Westford, MA, and Staines, UK, February, 17, 2009 – Sonus Networks, (Nasdaq: SONS), a market leader in IP communications infrastructure, today announced the MobilEnterprise FMC, a business services solution which enables mobile and converged operators to respond cost effectively to the demands of smart phone users in enterprises across the world. This new solution enables operators to protect margins and reduce network costs in an increasingly price competitive market.

By anchoring session control at the application layer, rather than the session/bearer layer, Sonus has enabled device independent service mobility enabling the user to take full advantage of enterprise features and leverage the growing usage of picocell technology to improve in-building coverage. With many workers using the mobile phone as their primary communication tool - inside the office or on the road - the ability to seamlessly connect is paramount.

"Many mobile operators are looking for faster evolution paths that will transform their networks from circuit based voice channels in combination with packet data, to becoming wholly IP based," commented Shailin Sehgal, vice president marketing and product management at Sonus Networks. "This application layer solution allows the end user to use the device of their choice, while its hosted nature means that in-house management is no longer required, providing lower cost service delivery, greater quality of service and enhanced employee productivity. Seamless switching between the mobile and fixed IP network also ensures that calls are made on the most cost effective network while the reduced complexity means that the end user benefits from a single bill."

MobilEnterprise FMC solution leverages Sonus’ extensive Business Services portfolio by extending integrated business group and VPN services, with enhanced and super user services such as group hunting, group call pick up, find me follow me, attendant console, call centre agent and unified messaging as well as integration with Microsoft OCS/LCS and Sonus’ Enhanced Service Portal for the delivery of unified communications (UC), to both mobile Centrex and IP Centrex devices.

As a part of the MobilEnterprise FMC solution, Sonus’ MobilEdge® Mobility Manager leverages its secure integration of wireless Pico, future super Femto and WiFi (VCC) based Mobile Centrex devices with SIP based IP Centrex and/or existing IP PBXs. In this way the Sonus MobilEdge Wireless Access Node provides the mobile operator with good quality of service within the enterprise coverage area as well as ensuring the optimal use of expensive Macro network resources through off loading to an enterprise based IP radio access network (e.g. Pico cell or WiFi).

About Sonus Networks

Sonus Networks, Inc. is a market leader in IP communications infrastructure 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 our Annual Report on Form 10-K for the year ended December 31, 2007 and all subsequent Quarterly Reports on Form 10-Q, which identify important risk factors that could cause actual results to differ from those contained in the forward-looking statements. Risk factors include among others: the Company’s ability to align its cost structure with market conditions, 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; 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:

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

EMEA Media Contact:
Lauren Bishop/Lucia Barbato
+44 (0) 20 7107 2479/2480
sonus.team@catalysis.co.uk