Sonus Networks Unveils New Mobile Technology to ShapeWireless Broadband World

Sonus mobilEdge™ Expands Wireless and Wireline Service Convergence and Enables New Revenue Generating Services

WESTFORD, Mass., and BARCELONA, Spain, February 11, 2008 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider IP-voice infrastructure solutions, today at Mobile World Congress in Barcelona unveiled its latest wireless technology that will allow mobile operators to rapidly increase their average revenue per user (ARPU) and leverage their existing high-speed data networks. Sonus' new mobilEdge™ Wireless Access Node, integrates seamlessly with the Global System for Mobile Communications (GSM) enabling operators to deliver never before seen services over existing high-speed data networks cost-effectively and securely.

The new carrier-class product provides consumers with improved access to 2.5G and 3G mobile multimedia services, while enabling network operators to effectively deliver quadruple-play services (voice, video, data and mobility) and expand their wireless network coverage. Sonus will be demonstrating its mobilEdge technology at its booths at Mobile World Congress, # 2E58 and 2E66.

"Macro mobile phone networks were built primarily with outdoor usage in mind and to deliver a separate set of services from wireline networks. For today's consumers, however, the mobile phone is a hub for communication and entertainment, regardless of location, and users want their portfolio of services available on both their mobile and fixed line phones. The Sonus mobilEdge Wireless Access Node not only expands network coverage in a cost-effective manner, it also streamlines the delivery of media-rich services improving the value mobile network operators can offer to their customers," said Hassan Ahmed, president, chairman and CEO, Sonus Networks. "This is a really exciting turning point for mobile networks."

Sonus' mobilEdge lets network operators combine their high-speed data networks with picocell or femtocell technology to maximize the investment they have previously made in their wireless broadband networks. Further, the mobilEdge allows operators to generate increasing minutes and improve the average revenue per user with broader wireless access and additional services. 

With Sonus' mobilEdge, subscribers enjoy seamless mobile coverage and a rich array of new IP-based multimedia services, while network operators can realize increased revenue, reduced churn, and lower costs.

Technology Overview

The Sonus MobilEdge Wireless Access Node serves as an anchor node bridging femtocell and picocell access networks, high-speed wireless data networks and IP-based core wireless networks. The mobilEdge supports today's need for 2G GSM and 3G UMTS femtocell and picocell access points for residential and enterprise use, including both in-building coverage and outdoor in-fill applications. In addition, it is fully compliant with the ongoing development of the LTE and SAE efforts within the 3GPP and provides an ideal integration node for 4G radios as they are introduced into the network.

Through standard SIP signaling, the mobilEdge makes centralized IP-based services available to both wireline and wireless subscribers. And by handling mobility-related procedures at the edge of the IP core, the mobilEdge allows IP core and access networks to evolve independently.

The mobilEdge platform leverages the mobile switching technology developed by Zynetix, a company Sonus acquired in April 2007, and Sonus' own field-proven GSX switching platform that drives over 36 billion VoIP minutes a month. With over 100 systems installed on five continents, the Zynetix mobile switching technology is a proven, field-deployed product. It supports common mobile phone call models, provides tightly integrated mobility management, and works with a range of pico/femtocell products.

The industry-leading Sonus GSX is a globally deployed platform. Other GSX-based products provide call routing, TDM-to-IP gateway functions, and secure IP-to-IP border switching. Integrated with the feature-rich Sonus product line, the GSX delivers proven SIP call control and carrier-grade availability on a hardened, highly scalable platform. By integrating the Zynetix mobile switching technology with Sonus' GSX platform, Sonus has created an innovative solution for connecting broadband-attached picocells and femtocells to an IP/SIP core.

The Sonus mobilEdge platform is available in two versions

• " MobilEdge9000 is a modular carrier-class platform that is highly scalable, and fully redundant. It can support up to 640,000 mobile subscribers in a single chassis, which is 16U high and fits in a standard 19-inch (600 mms) wide telecom rack
• " MobilEdge4010 is a fixed-configuration carrier-class platform that is fully redundant, but targeted at smaller central offices. It can support up to 25,000 mobile subscribers in a single chassis, which is 3U high and fits in a standard 19-inch (600 mms) wide telecom rack

About Sonus Networks

Sonus Networks, Inc. is a leading provider of IP-voice 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 September 30, 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; 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.

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.