Japanese Consumers have Access to Advanced Residential VoIP Services Based on Sonus Technology

CHELMSFORD, Mass., and CHICAGO, IL, June 08, 2005 – Today at SUPERCOMM 2005, Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, announced Jupiter Telecommunications Co., Ltd. (J:COM) is implementing the Sonus platform as the foundation for its new VoIP network to deliver enhanced residential voice services to consumers throughout Japan.

“Sonus has been focused from inception on delivering solutions to network operators that enable new services as well as the ability to offer integrated multimedia services,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “The ability to deliver telephony services using IP technology is revolutionizing communications globally. We are proud to be working with J:COM on their residential voice service that meets the quality and reliability requirements that Japanese consumers expect from their fixed-line service.”

Under the terms of the agreement, Sonus is providing its GSX9000TM Open Services Switch, PSXTM Call Routing Server, SGXTM Signaling Gateway, as well as the Sonus InsightTM Management System. Additionally, J:COM is deploying Sonus' PacketCableTM qualified ASXTM  Call Management Server(CMS). Further expanding its services capabilities, J:COM will also be utilizing Sonus' latest product offering, the IMX Application Platform to support the delivery of enhanced residential voice services.

J:COM launched its IP telephony service called "J:COM PHONE" on April 20, 2005. The introduction of this offering enables Sapporo customers to subscribe to all three J:COM service lines and to realize associated package savings for those customers who subscribe to more than one J:COM service. J:COM currently offers multi-channel cable television services (J:COM TV) and high-speed Internet access services (J:COM Net) in the area. J:COM initially selected Sonus for a field trial in Tokyo, and based on its success has decided to expand the deployment to a broader area.

“We are committed to providing services that enhance our customers' lives by delivering products that anticipate and fulfill their lifestyle needs,” said Shunzo Yamaguchi, Director and SVP of Engineering, J:COM. “By deploying the Sonus platform for our telephony services, we expect to further strengthen our highly advanced network.”

About Jupiter Telecommunications Co., Ltd. (J:COM)

Established in 1995, Jupiter Telecommunications Co., Ltd. (J:COM) is Japan's largest multiple system operator based on the number of subscribing customers, serving 1,922,900 subscribing households (as of March 31, 2005) in the Hokkaido, Kanto, Kansai, and Kyushu regions. Based in Tokyo, J:COM is the corporate entity that provides cable television, high-speed Internet access and telephony services to customers across Japan through 17 managed franchises (as of April 1 2005) operating at the local level. The number of serviceable households or "homes passed" in J:COM franchises in Hokkaido, Kanto, Kansai and Kyushu is approximately 7.1 million (as of March 31, 2005). J:COM's principal shareholders are LMI/Sumisho Super Media, LLC., Microsoft Corporation, and Sumitomo Corporation.. (as of December 31, 2004). J:COM is a public company, trading on the JASDAQ stock exchange under the symbol JCOM. For more information, visit J:COM's website at http://www.jcom.co.jp/corporate/english.html.

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice over IP (VoIP) infrastructure solutions for wireline and wireless service providers. 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.