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WESTFORD, Mass., October 9, 2002 – Sonus Networks, Inc. (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today reported its financial results for the third quarter ended September 30, 2002. These results are consistent with the revised business outlook the Company provided on September 24, 2002.

Revenues for the third quarter of fiscal 2002 were $7.4 million compared with $40.3 million in the same period last year. Adjusted net loss for the third quarter of fiscal 2002 was $14.6 million or $0.08 per share compared with an adjusted net loss for the third quarter of fiscal 2001 of $11.4 million or $0.06 per share. Actual net loss for the third quarter of fiscal 2002 was $21.6 million or $0.11 per share compared with an actual net loss for the third quarter of fiscal 2001 of $498.2 million or $2.81 per share.

Revenues for the first nine months of fiscal 2002 were $49.9 million compared with $134.3 million in the same period last year. Adjusted net loss for the first nine months of fiscal 2002 was $37.9 million or $0.20 per share compared with an adjusted net loss for the first nine months of fiscal 2001 of $10.1 million or $0.06 per share. Actual net loss for the first nine months of fiscal 2002 was $55.7 million or $0.30 per share compared with an actual net loss for the first nine months of fiscal 2001 of $632.0 million or $3.71 per share.

A reconciliation of adjusted to actual net loss for the periods is as follows:

"This continues to be a challenging period for the telecommunications industry, and that certainly has impacted our financial results for the quarter," said Hassan Ahmed, president and CEO, Sonus Networks. "During these times, we remain keenly focused on the priorities that we laid out at the beginning of the year – building our customer base, developing industry-leading technologies and preserving our financial strength. Our leading products and customer support capabilities give us a strong competitive position, and we have continued to add important new customers each quarter."

Sonus further expanded its customer base in the third quarter, announcing a deployment with Deutsche Telekom's T-Systems International division. T-Systems has chosen Sonus to build out its next-generation voice over IP (VoIP) network to provide large multinational customers with enhanced voice services, such as global voice VPN (virtual private network) and sophisticated call center routing facilities.

Sonus continued to develop new industry partnerships through the Open Services Partner AllianceSM (OSPA), broadening Sonus' solutions offerings for enhanced services, access solutions and QoS management. New partners joining the OSPA during the quarter include InnoMedia, Personeta, Psytechnics, SkyWave, Terayon and Unisys.

Sonus also announced that for the eighth consecutive quarter, the company has been ranked the leading provider of carrier-class packet voice equipment. Respected industry research firms In-Stat/MDR, Infonetics Research and Synergy Research Group issued Q2 2002 market share reports naming Sonus the industry leader in key packet voice market segments.

About Sonus Networks

Sonus Networks, Inc., is a leading provider of packet voice infrastructure products for the new public network. 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 Sonus' Quarterly Report on Form 10-Q, dated August 14, 2002 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.

Sonus is a registered trademark of Sonus Networks. Open Services Architecture is a trademark of Sonus Networks and Open Services Partner Alliance 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.