RANGER Wireless Solutions Implements Sonus Infrastructure to Offer Wireless Carriers Effective 611 Service

CHELMSFORD, Mass., July 05, 2005 – Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, today announced that RANGER Wireless Solutions is deploying a full suite of Sonus product offerings, including the GSX9000™ Open Services Switch, the ASX™ Call Management Server, the PSX™ Call Routing Server and the Sonus Insight™ Management System. RANGER Wireless delivers a patented 611 Roaming Service™, which routes roaming wireless customers to their home call centers.

Traditionally, wireless operators have delivered customer service beyond the boundaries of their licensed service areas through partnerships with other providers. When subscribers travel outside of their home network, dialing 611 routes the call to the serving carrier's customer care center or roamers hear a recorded announcement instructing them to call their service provider directly. Supported by its Sonus-based VoIP network, RANGER is updating its patented 611 Roaming Service that enables cellular callers to connect to their carriers' customer care center regardless of the subscriber's physical location, reducing expensive interconnection and service costs. Further, by implementing a Sonus architecture, RANGER can integrate new services and continue to rapidly and more efficiently expand its network than it would if relying on traditional telephony architectures. Today, RANGER serves over 40 wireless carriers in the US, including five of the top 10 cellular providers.

"One of the benefits of an IP architecture is that it creates an environment favorable to the rapid development and rollout of innovative services that promote customer loyalty, like the 611 service offered by RANGER Wireless Solutions," said Steve Edwards, chief marketing officer, Sonus Networks. "As all-IP networks become more pervasive, the ability to deliver a differentiated experience to the consumer will be an invaluable ingredient in the promotion of customer loyalty."

“Wireless carriers face increasing competition, particularly in pricing and customer retention. Offering personalized, air-time free customer support is a key selling point and often a significant reason that subscribers stay with a particular carrier,” said Irv Wolfson, manager of new business development, RANGER Wireless Solutions. “By delivering our 611 Roaming Service on a Sonus-based architecture, we empower carriers to offer a valuable customer service, while at the same time reducing operating expenses.”

About RANGER Wireless Solutions

RANGER Wireless Solutions has been in business since 1995, and serves five of the top ten cellular carriers, handling more than two million domestic and international calls per month. RANGER© developed the patented technology behind their 611 Roaming Service™, Home Customer Care©, the application for seamlessly routing cellular users dialing 611/*611 to their home customer care center of participating cellular providers. Additional information on RANGER is available at www.611roaming.com.

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice over IP (VoIP) infrastructure solutions for wireline and wireless service providers. With its Open Services Architecture^TM  (OSA), Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking and tandem switching, residential and business access, network border switching and enhanced services. Sonus' voice infrastructure solutions, including media gateways, softswitches and network management systems, are deployed in service provider networks worldwide. Sonus, founded in 1997, is headquartered in Chelmsford, 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 the "Risk Factors" section of Sonus' Annual Report on Form 10-K dated March 15, 2005, and the "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated May 9, 2005, both filed with the SEC, which identify important risk factors that could cause actual results to differ from those contained in the forward-looking statements. In addition, 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.

Sonus is a registered trademark of Sonus Networks. Open Services Architecture, GSX9000 and Insignus are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.