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Network to Support Enhanced Voice Services, Internet 'Dial Tone' 

LITTLETON, Colo. and WESTFORD, Mass., July 25, 2000 – Time Warner Telecom Inc. (Nasdaq: TWTC - news), a leader in building local and regional optical networks to deliver its comprehensive suite of converged communications products to businesses, today announced an agreement to purchase packet telephony infrastructure solutions from Sonus Networks (Nasdaq: SONS - news) to build out a network that will support next generation voice and voice/data services. 

Time Warner Telecom will purchase equipment to deliver next generation business class telephony services and Internet `dial tone' from Sonus under terms of a three-year agreement valued at up to $75 million. With this deployment, Time Warner Telecom becomes the first major local exchange carrier to massively deploy packet telephony as part of a next generation service delivery platform/architecture. 

During the first phase of its network implementation this year, Time Warner Telecom has begun to deploy the Sonus Packet Telephony suite, including the GSX9000(TM) Open Services Switch, the PSX6000(TM) SoftSwitch and the SGX2000(TM) SS7 Signaling Gateway, for Internet `dial tone' in a number of its markets. Sonus will also provide engineering, installation, technical support and other professional services. In the second phase of its network implementation, Time Warner Telecom will bring advanced integrated services, including new voice over IP offerings, to business customers in each of its markets. 

"The telephony industry is at a critical juncture in its evolution with carrier class packet telephony solutions now coming to market," said Larissa Herda, President and CEO, Time Warner Telecom. ``Packet telephony and converged network services will change the way customers manage their telecommunications network. Sonus is clearly a leader in this space."

"Time Warner Telecom has the vision and industry leadership to deliver the most modern and innovative business communications solutions available," said Hassan Ahmed, president and CEO, Sonus Networks. "We believe this strategic partnership with Time Warner Telecom will help us both to develop infrastructure and solutions to meet customer needs and achieve business objectives.'' 

"Meeting the explosive demand for IP dial tone is not an easy task," Ms. Herda said. "Time Warner Telecom has made the commitment now to massively deploy packet telephony solutions to meet ISP customers' needs for Internet dial tone and our business customers' needs for more efficient next generation applications."

"The Sonus solutions enable us to achieve incredible density, scalability and a reduced time to market that help meet our immediate requirement for Internet dial-up traffic," Ms. Herda added. ``More importantly, it allows us to build a foundation to deliver a range of new, enhanced voice and voice/data services, such as integrated web and click-to-talk web services for end user customers."

To meet market demand and to deliver Internet dial tone, Time Warner Telecom has begun to deploy the Sonus switches to augment its existing Class 5 circuit switches. In the future, Time Warner Telecom plans to use the Sonus infrastructure to deliver traditional local and long-distance voice services, as well as new voice over IP-based services such as unified communications, single number service, call centers and more. 

About Time Warner Telecom 

Time Warner Telecom Inc., headquartered in Littleton, Colo., builds local and regional optical networks to deliver ``last-mile'' broadband data, Internet access and voice for businesses. The Company serves customers in 22 U.S. metropolitan areas including: Austin, Dallas, Houston and San Antonio, Texas; Charlotte, Fayetteville, Greensboro and Raleigh, N.C.; Albany; Binghamton, New York City and Rochester, N.Y.; Northern New Jersey; Cincinnati and Columbus, Ohio; Memphis, Tenn.; Orlando and Tampa, Fla.; Indianapolis, Ind.; Milwaukee, Wisc.; San Diego, Calif.; and Honolulu, Hawaii. Time Warner Telecom plans to activate its Los Angeles/Orange County, Calif. and Dayton, Ohio markets this year and to launch services over its optical networks in Denver, Atlanta, Chicago, Minneapolis and Columbia, S.C. next year. For more information about Time Warner Telecom, please visit www.twtelecom.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 Architecture(TM) (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 market share 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. 

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 May 24, 2000, 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 our products, rapid technological and market change and manufacturing and sourcing risks. 

GSX9000, PSX6000, SGX2000 and Open Services Architecture are trademarks of Sonus Networks. All other company and product names may be trademarks of the respective companies with which they are associated.