Sonus Networks Schedules Conference Call to Provide Q1 FY2004 Business Update

Company contacts:

 Investor Relations:
Jocelyn Philbrook
978-614-8672
jphilbrook@sonusnet.com
 Media Relations:
Beth Morrissey
978-614-8579
bmorrissey@sonusnet.com

CHELMSFORD, Mass., April 22, 2004 – Sonus Networks (Nasdaq: SONSE), a leading provider of voice over IP (VoIP) infrastructure solutions, today announced that it will host a conference call and simultaneous webcast to provide an update on its business for the first quarter ended March 31, 2004.  The conference call and webcast will be held on Tuesday, April 27, 2004 at 4:45 pm Eastern.

To listen via telephone:

Dial-in number: +1-888-326-7098 or +1-706-758-2365

To listen via the Internet:

Sonus will host a live webcast of the conference call.  To access the webcast, visit the Sonus Networks Investor Relations site at http://www.sonusnet.com.

Replay

A telephone playback of the call will be available following the conference and can be accessed by calling +1-800-633-8284 or +1-402-977-9140.  The access code for the replay is 21193935.  The telephone playback will be available through May 11, 2004.

The webcast will be available on the Sonus Networks Investor Relations site through April 27, 2005.  To access the replay of the webcast, visit the Investor Relations site at http://www.sonusnet.com.

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice over IP (VoIP) infrastructure solutions for wireline and wireless service providers.  With its Open Services ArchitectureTM  (OSA), 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.

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