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Integrated Communications Provider rolls out new secure VoIP offerings using Sonus Networks

CHELMSFORD, Mass., and GREENVILLE, SC - March 22, 2005 - Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, announced today that NuVox Communications is introducing its new business VoIP service that will be delivered over its Sonus-based network. Building on its existing long-distance network, NuVox Communications is now expanding their network, which includes Sonus' GSX9000TM and InsignusTM  Softswitch, and broadening its suite of services in order to deliver a comprehensive set of IP telephony applications to enterprise clients.

NuVox Communications began deploying its Sonus-based network throughout its 16-state footprint in the Southeastern and Midwestern U.S. in January 2003. With the Sonus system as the foundation for its long-distance voice network, NuVox has established a platform that supports an extensive portfolio of enhanced services. NuVox is now further leveraging this investment to expand its service offerings and to provide businesses with the benefits of a secure VoIP network.

"NuVox is experiencing increasing demand for differentiated services from our business customers," said Paul Pitts, executive vice president of operations, planning, and engineering for NuVox Communications. "Thanks to our decision to place Sonus at the core of our network, we have been able to scale our network easily to address these new opportunities. Sonus Networks delivers a proven solution that has exceeded our expectations in scalability and functionality, and we look forward to continuing our partnership with Sonus."

"The access market is expanding rapidly, and NuVox is again staying ahead of the curve with its new VoIP product offering. Sonus is leading the industry with customer deployments around the world delivering a broad portfolio of access services," said Steve Edwards, chief marketing officer for Sonus Networks. "Sonus is proud to partner with NuVox to build a VoIP network that supports industry leading applications. We look forward to the ongoing expansion of this deployment as NuVox continues to grow its business."

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 ArchitectureTM  (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 http://www.sonusnet.com.

About NuVox Communications

NuVox Communications is a privately held Integrated Communications Provider (ICP) offering a full array of communications services for business customers including data, Internet, voice, and other advanced communications solutions. The company serves over 41,000 business customers across Florida, Georgia, South Carolina, North Carolina, Tennessee, Alabama, Kentucky, Mississippi, Louisiana, Arkansas, Oklahoma, Kansas, Missouri, Illinois, Indiana, and Ohio. On the Web www.nuvox.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/A dated July 28, 2004 and filed with the SEC, and the "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated November 9, 2004 and 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.