Sonus Networks Enables Wireless Operators to Make Flat Rate Pricing a Profitable Reality

IP Connectivity Allows Mobile Operators to Turn Profit at the Edge

Westford, MA., and Las Vegas, NV., April 02, 2008 – Sonus Networks, Inc. (Nasdaq: SONS), the market leader in IP communications infrastructure, is helping mobile operators to embrace flat rate pricing plans without the major increases to operating costs usually associated with increased traffic or subscribers. The core infrastructure components offered by Sonus can be integrated to enable operators to retain competitive pricing models through IP-to-IP peering, advanced media services and transcoder-free operation. Sonus Networks is exhibiting these and other wireless solutions at CTIA 2008, Las Vegas, at Booth #3439.

Consumer demand is pushing wireless operators to deliver flat rate pricing, both in the U.S. and across Europe. To remain competitive in a market with downward price pressure, operators face the challenge of reducing and controlling network infrastructure costs. Flat rate plans will inevitably lead to an increase in call volume, which will become costly for carriers who are required to deliver increasing traffic volume to complete calls outside of their wireless network.

"The key to addressing flat rate pricing for carriers lies in the optimization of their current networks. From bandwidth, to routing, to session and border management, carriers need to drive efficiency in both operational and capital expenditures," said Vikram Saksena, chief technology officer, Sonus Networks. "Using the distributed, scalable technology in the Sonus IP infrastructure, carriers can squeeze substantial cost from their networks and provide a flexible foundation to build the services needed to attract new customers and offer new revenue opportunities."

Mobile operators can optimize their networks through the consolidation of routing decisions in a central location.

With the Sonus PSX routing engine, Sonus can deliver enhanced network performance and efficiency by providing mobile operators with "transcoder-free operation" (TrFO). By eliminating the need to convert signals between mobile to mobile calls, network operators free additional network capacity. A scalable routing solution is critical when the mobile call is routed between multi-vendor mobile switching centers.

Operational expenditure can also be reduced through IP-wireless peering that provides a fixed, low-cost solution, connecting the IP-enabled wireless network with a peered IP network. The flexibility that IP can give to wireless carriers versus connecting back to a TDM network allows for faster deployment and network change to occur. Sonus' Network Border Switch can remove this costly IP to TDM conversion.

"While the potential benefits of IP-peering for mobile operators are numerous, controlling network costs is among the most crucial concerns of operators moving to a flat-rate pricing model," said Joe McGarvey, Principle Analyst, Carrier Internet Packet Telephony with Current Analysis. "Additionally, IP enables operators to scale to create new services and applications, allowing operators to provide additional value to subscribers while generating new revenue streams."

IP peering within a Sonus infrastructure allows wireless operators to regain pricing control and create reliable pricing models for flat rate plans. In addition to cost savings, benefits include:

• No dependency on the transit PSTN network
• The ability to access TDM networks via peering relationships without heavy investment in TDM equipment in the wireless network
• Ability to deliver a flexible, IP-based platform while maintaining existing traffic controls and billing procedures

With more than 13 billion minutes of mobile IP-Voice traffic running across its networks, Sonus has established an important presence in this rapidly growing segment of the market. Sonus solutions include NBS™, GSX9000™, PSX™ Call Routing Server, SGX™ Signaling Gateway, and the Sonus Insight Management System.

About Sonus Networks

Sonus Networks, Inc. is a leading provider of IP communications 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-K for the period ended December 31, 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, except as required to do so 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.