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Sonus Networks' INIP Powered Program Continues to Create "Powered" Products as Mediatrix Completes Testing of APA III IADs

WESTFORD, Mass., and MONTREAL, Quebec, January 30, 2001 - Sonus Networks, (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, and Mediatrix Telecom, Inc., today announced that the Mediatrix APA III is now "INIP PoweredSM." Specifically, the APA III, an integrated access device (IAD), received this designation after successfully completing interoperability testing with Sonus' INtelligentIPr softswitch at the Sonus INIP Powered Interoperability Laboratory in Richardson, Texas.  

The APA III family of IADs is Mediatrix's Internet Protocol (IP) solution designed for small and medium-sized businesses.  The APA III line of IADs connects conventional telephones or fax machines to a local area network (LAN).  The APA IIIs access an intranet or the Internet to cost-effectively leverage a business' existing equipment and networks, and allow for a scalable implementation, as well as integration between a business' voice and data network.  In so doing, the APA IIIs provide small businesses with the benefits of packet telephony, such as long distance savings and next-gen application implementation, without requiring costly network and telephone equipment replacements.    

"The real power of the INIP Powered Program is its ability to coordinate the efforts of carriers and vendors to bring IP solutions to the end user," said Terri Griffin, vice president, INIP marketing, INtelligentIP division, Sonus Networks.  "Now that the Mediatrix APA III is "INIP Powered," carriers and DSL service providers can more easily extend converged, IP-based voice and data services to small businesses, with the assurance of end-to-end interoperability." Before becoming "INIP Powered," Mediatrix joined Sonus' INIP Powered Partner Program, which now has 66 telecom partners. It is the first such program in the industry and accelerates deployment of voice services by integrating standards-based softswitches, media gateways, service creation and delivery systems, and unified voice and data applications with the INtelligentIP softswitch.  Products that successfully complete the interoperability can use the "INIP Powered" logo, signifying to carriers that the product is interoperable with the INtelligentIP softswitch.   

"Interoperability of all network devices, from the switching devices at the core of the network to the access devices at the edge of the network, is paramount," said Stefano Genoni, director of business development of Mediatrix Telecom.  "We are proud to have obtained "INIP Powered" status.  This lets businesses and carriers know that our APA III line can be easily implemented to deliver to small businesses the considerable benefits of packet telephony, including cost savings and a host of new voice and data applications."

Sonus' INtelligentIP softswitch is a scalable, carrier-grade softswitch platform that provides carriers an open, cost-effective solution to the packet-circuit network challenge. The INtelligentIP softswitch integrates with application software and media gateway hardware, enabling carriers to successfully compete in the highly dynamic and cost-conscious telecommunications marketplace.  The INtelligentIP softswitch also allows the carriers that build and operate converged networks to provide new telecommunications services for enterprises and consumers more rapidly and at lower costs.

About Mediatrix Telecom, Inc.

Mediatrix, a privately-owned company, is a leading supplier of high-quality, standards-based Internet Protocol (IP) Services Application Server Software and intelligent communication devices with emphasis on Access and Trunking Gateways.  Mediatrix' mission is to enable its business partners to leverage on their market share by shortening time to market and by providing them cost effective technological solutions that enable their customers to successfully migrate voice and fax to the IP future.  For more information, visit Mediatrix' website at www.mediatrix.com. 

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice infrastructure products for the new public network.  Sonus' solutions enable service providers to deploy an integrated network capable of carrying both voice and data traffic, and to deliver a range of innovative, new services.  The Sonus Open Services ArchitectureO (OSA) and award-winning Packet Telephony suite cut the time-to-market for competitive new service products, allowing carriers and third-party developers to expand marketshare and build important new revenue streams.  Its highly scalable products fully interoperate with and extend the life and utility of today's public network.  Sonus embodies in its management and staff decades of experience in developing carrier-class voice, data and multimedia solutions for implementation in the world's largest networks.  Sonus, founded in 1997, is headquartered in Westford, Massachusetts.  Additional information on Sonus is available at http://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 Sonus' Prospectus, dated January 12, 2001, and associated Registration Statement on Form S-4, filed with the SEC, which identifies important risk factors that could cause actual results to differ from those contained in the forward-looking statements.  These risk factors include, among others, the Company's ability to grow its customer base, dependence on new product offerings, market acceptance of its products, rapid technological and market change, integration risks relating to the acquisition of telecom technologies and manufacturing and sourcing risks.

INtelligentIP is a registered trademark of Sonus Networks. Open Services Architecture is a trademark of Sonus Networks.  INIP Powered is a service mark of Sonus Networks.  All other company and product names may be trademarks of the respective companies with which they are associated.