Tdsoft Joins Sonus Networks Open Services Partner Alliance

Companies Partner to Drive Global Adoption of Next-Generation Services

CHELMSFORD, Mass., and HERZLIA, Israel, June 22, 2005 – Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, and Tdsoft Ltd., a global provider of voice over IP (VoIP) gateways, announced today that Tdsoft has joined Sonus' Open Services Partner Alliance (OSPA). Additionally, the companies have entered into a non-exclusive reseller agreement, under which Sonus will resell the TdGATE reverse access gateway products to service providers globally.

The TdGATE products allow service providers to integrate their legacy digital loop carrier networks (DLC) with their next-generation network using V5.1, V5.2 and GR303 protocols. When combined with the Sonus IMS Architecture, network operators globally are able to migrate their access networks to IP, delivering enhanced next-generation services on every subscriber line without replacing or upgrading their existing DLC infrastructure. This reduces capital and operational costs, while providing a future migration path to an all-IP network.

"Sonus Networks, a recognized industry leader, since its inception has been focused on carrier-grade VoIP networks," said Yosi Albagli, Tdsoft's president and CEO. "Tdsoft's reverse access gateways complement Sonus' offering, and we look forward to working together with Sonus to target service providers globally that are deploying packet voice solutions in their access networks."

“The ability to deliver next-generation services to consumers regardless of their physical connection to the network is critical to network operators around the world,” said Steve Edwards, chief marketing officer, Sonus Networks. “Our partnership with Tdsoft allows service providers to deliver a robust consumer VoIP service in those regions where broadband access is limited. Further, by partnering with an accomplished provider of reverse access gateways, Sonus is continuing to provide solutions that deliver the reliability and scalability that service providers demand.”

Launched in June 1999, the OSPA is the industry's largest interoperability program dedicated to driving standards-based interoperability between applications, third-party vendors and Sonus products. During the last six years, the OSPA has gained significant industry momentum, with a membership of over 150 leading independent vendors. Network operators globally rely on Sonus' comprehensive testing to deploy "best-of-breed" VoIP networks without costly extended testing and trial periods. Sonus and its partners collaborate to deliver end-to-end VoIP network solutions using the industry's leading technologies and applications. Additional information on the OSPA is available at www.sonusnet.com/partners.

About Tdsoft Ltd.

Tdsoft is a leading global provider of voice over IP (VoIP) gateways for carriers. At the forefront of gateway development for over a decade, Tdsoft solutions enable telecommunications service providers to leverage existing infrastructure while migrating smoothly to the new public network. Deployed worldwide by dozens of major carriers seeking best-of-breed solutions, Tdsoft's standards-based VoIP gateways are interoperable with leading Class 5 legacy switches and softswitches. Tdsoft is privately owned with strong investor backing from prominent US and international venture capital firms and corporations. For more information about Tdsoft, visit www.tdsoft.com.

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, 2005,4 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.