Press Release

USA DATANET DEPLOYING BROADSOFT AND SONUS SOLUTION FOR HOSTED PBX AND IP CENTREX SERVICES

Market Leaders Move VoIP into the Mainstream with Integrated Applications for Revenue-Generating Services

Chicago, IL - SUPERCOMM, June 21, 2004 - USA Datanet, one of the nation's leading providers of IP enabled enhanced services, Sonus Networks (Nasdaq: SONSE), a leading provider of carrier voice over IP (VoIP) infrastructure solutions, and BroadSoft Inc., the leading provider of network communications platforms, today announced that USA Datanet is expanding its next-generation network deployment with Sonus Networks to incorporate fully integrated hosted PBX and IP Centrex applications based on BroadSoft's BroadWorksâ platform.

"We are committed to helping our customers improve their bottom line with cost-effective, innovative and reliable VoIP services," said David Montanaro, CEO and president of USA Datanet. "By seamlessly merging BroadSoft's feature sets with Sonus' VoIP network infrastructure, these two companies enabled us to quickly deliver voice services that businesses are looking for today."

USA Datanet is offering both commercial and wholesale hosted enterprise voice services based on Sonus' Open Services ArchitectureTM (OSA). USA Datanet first deployed Sonus' GSX9000TM Open Services Switch, the InsignusTM Softswitch and the Sonus InsightTM Management System in 2000, initially to deliver long distance voice services. USA Datanet is now expanding its Sonus-based next-generation network to include BroadSoft's BroadWorks platform. The combined Sonus/BroadWorks solution provides a comprehensive range of applications including hosted PBX, IP Centrex, and the latest in collaborative conferencing fully integrated into a single network communications platform.

"We're pleased to be working with BroadSoft to enable USA Datanet to provide best-of-breed services to businesses looking for a competitive edge," said Hassan Ahmed, president and CEO, Sonus Networks. "Today's announcement builds on the success that we have achieved with USA Datanet over the past four years, and demonstrates the strength of our long-term partnership with BroadSoft."

"BroadSoft's BroadWorks has been commercially deployed in carrier networks with Sonus' OSA solutions for three years," said Mike Tessler, CEO and president at BroadSoft. "We're proud to have been able to provide a strong foundation to support USA Datanet's new and exciting voice services. By working together, we are proving that VoIP is moving into the mainstream with mature channels that deliver fully integrated advanced applications to leading carriers."

ABOUT USA DATANET
USA Datanet is a leading, VoIP technology company headquartered in Syracuse, New York. The company uses its early-adopter experience to deliver high quality voice, data, video, conferencing and enhanced services. Founded in 1998, the company uses soft switch technology with a proprietary network design that now supports over 460,000 customers in the residential and business markets. For more information about the company, please visit www.usadatanet.com.

ABOUT BROADSOFT
BroadSoft is the leading supplier of network communications platforms to service providers and channels in the enterprise and residential markets. BroadSoft's flagship product, BroadWorks, provides a comprehensive range of applications including Hosted PBX, IP Centrex, residential broadband and collaborative conferencing, fully integrated into a single platform. The company has the largest customer base in its space worldwide, including MCI, SingTel and Telstra. BroadSoft is located near Washington, DC, in Gaithersburg, Maryland, and maintains a research and development facility in Montreal, Canada. Additional information can be found at www.broadsoft.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 ArchitectureÔ (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 www.sonusnet.com.

This release may contain projections or other forward-looking statements regarding future events or the future financial performance of Sonus 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 "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated November 10, 2003 and 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, uncertainties regarding the timing of the Company's completion of the audit and filing of its Annual Report on Form 10-K/A for 2003 and future periodic reports, the possibility that Sonus may be delisted from Nasdaq, risks as to the litigation and SEC investigation with respect to the foregoing and related matters, unforeseen issues encountered in the completion of the audit, uncertainties regarding the extent to which prior period financial statements will be restated, the continued adverse effect of developments in the telecommunications industry, Sonus' ability to grow its customer base, dependence on new product offerings, market acceptance of its products, competition from large incumbent vendors, rapid technological and market change and manufacturing and sourcing risks. 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, Insignus and Sonus Insight are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.

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BroadSoft and BroadWorks are registered trademarks of BroadSoft, Inc. All other names are trademarks of their respective companies.