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Oni Implementing Sonus Packet Voice Solution in its Network; Carrier to Deliver Long Distance and Local Voice Services on Sonus Platform

WESTFORD, Mass., October 13, 2003  – Portuguese telecom provider Oni Telecom and Sonus Networks (Nasdaq: SONS) today announced that Oni is partnering with Sonus to build out a packet voice network. With the Sonus-based IP voice infrastructure, Oni will offer residential and corporate customers a variety of telephony services, including local and long distance voice services, as well as enhanced services such as voice VPN (virtual private network).

"When evaluating solutions for our next-generation voice network, we required an infrastructure that offered carrier-class reliability and scalability, as well as the flexibility to enable the evolution of our services offering," said Pedro Norton de Matos, CEO, Oni Telecom. "Moreover, we sought a partner with extensive experience. After comparing competitive offerings, we found that Sonus' proposal was the most competitive."

In a multi-phase deployment, Oni is implementing the full set of Sonus voice infrastructure solutions: the GSX9000 Open Services Switch; the Insignus Softswitch, including the ASX Access Server, PSX Policy Server and SGX SS7 Signaling Gateway modules; and the Sonus Insight Management System. In the initial phase, which is currently underway, Oni is deploying the Sonus systems to deliver long distance voice services between the Portuguese mainland and the Azores. In subsequent phases of the rollout, Oni will utilize Sonus' ASX Access Server to provide local voice services to residential and corporate users, and will also offer enhanced services such as voice VPN.

"We're extremely excited that Oni has selected our Open Services Architecture and solutions as the platform for delivering comprehensive packet telephony capabilities to their customers," said Hassan Ahmed, president and CEO, Sonus Networks. "Oni is focused on achieving a leadership position in Iberian telecommunications, and we are pleased to be working with them to attain their objectives." 

About Oni

Oni is the market leader among the new fixed network operators. As a Global Telecommunications Operator that has been licensed to provide Fixed Telephone Services since the 1st of January 2000, Oni has seen the Iberian Peninsula as its natural market. The company is the vehicle chosen by four major Portuguese business groups for their entry into the telecommunications market: EDP " Electricidade de Portugal, BCP " Banco Comercial Portugu's; Brisa " Autoestradas de Portugal and Galp Energia SGPS. Oni offers a wide range of Voice, Data and Internet services to every segment of the market. It also possesses its own fibre optic network that covers 35,000 kilometres in Portugal and 2,000 kilometres in Spain, as well as two licenses to supply FWA direct access services in the 3600-3800Mhz and 26.5 GHz bands.

Continuously taking advantage of the opportunities presented by the liberalisation of the Iberian telecommunications market, Oni is investing heavily in the latter's conquest and in the satisfaction of an ever-growing number of both residential and business customers, in Portugal, and Business customers in Spain. Additional information about Oni is available at www.oni.pt.

About Sonus Networks

Sonus Networks, Inc., is a leading provider of packet voice infrastructure solutions for wireline and wireless service providers. With its Open Services Architecture (OSA), Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking, residential access and Centrex, tandem switching, and IP voice termination, as well as enhanced services. Sonus' award-winning 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 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 the "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated August 13, 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. These risk factors include, among others, the adverse effect of recent developments in the telecommunications industry, the weakened financial position of many service providers, Sonus' ability to grow its customer base, dependence on new product offerings, market acceptance of its products, 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. GSX9000, Insignus, Sonus Insight and Open Services Architecture are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.