CHELMSFORD, Mass., June 13, 2005 – Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, today announced that founder and chief technology officer (CTO) Mike Hluchyj will present at the Thomas Weisel Growth Forum being held in San Francisco, California on June 14, 2005 at 8:35 a.m. Pacific Time.

Interested investors can access live audio webcasts of the presentations on the Investor Relations section of the Sonus Networks website at http://www.sonusnet.com. A full schedule of Sonus Networks' investor activities is available on the Sonus Networks Investor Relations site.

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice over IP (VoIP) infrastructure solutions for wireline and wireless service providers. Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking and tandem switching, residential and business access, network border switching and enhanced services. Sonus' 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 Chelmsford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

Sonus is a registered trademark of Sonus Networks. Open Services Architecture, GSX9000 and Insignus are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.