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WESTFORD, Mass., April 4, 2002 - At the Spring 2002 Voice on the Net (VON) next week, Sonus Networks (Nasdaq: SONS) will highlight technology trends in packet voice infrastructure and related services through participation in several conference presentations, as well as live demonstrations of packet-based voice solutions and services. Spring 2002 VON is being held April 8-11, 2002 at the Washington State Convention and Trade Center in Seattle.

Industry experts from Sonus are taking an active role in the educational portion of the conference, and will be participating in the following sessions:

Monday, April 8, 2002, 4:00 pm - 4:20 pm
Pre-Conference Workshop: PSTN/IP Gateways and Softswitches
Speaker: Matt Holdrege, director of technology development

Tuesday, April 9, 2002, 11:15 am - 11:45 am
Industry Perspective
Speaker: Mike Hluchyj, founder and CTO

Tuesday, April 9, 2002, 2:15 pm - 3:20 pm
CALEA and Emergency Services in 911
Speaker: Matt Holdrege, director of technology development

Tuesday, April 9, 2002, 3:35 pm - 4:40 pm
VC: 1st and 2nd Round Funding
Speaker: Rubin Gruber, founder and chairman

Wednesday, April 10, 2002, 9:35 am - 10:45 am
Future of the Softswitch
Speaker: Mike Hluchyj, founder and CTO

Additional information on Spring 2002 VON can be found at http://pulver.com/von/

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.

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