WESTFORD, Mass., July 20, 2009 – Sonus Networks, Inc. (Nasdaq: SONS), providing network transformation through IP communications technology, today announced that it will release financial results for the second quarter 2009 prior to opening of the market on Thursday, July 30th, 2009, and will host a conference call with financial analysts and investors at 10:00 a.m. ET that day.

To listen live via telephone:

Dial-in number: 800-895-5087
International Callers: +1 303-223-0116

To listen via internet

Sonus will host a live webcast of the conference call. To access the webcast, visit www.sonusnet.com, About Us, Investor Relations.

Replay

A telephone playback of the call will be available following the conference and can be accessed by calling 800-633-8284 or for international callers, please call +1 402-977-9140. The reservation number for the replay is 21431767, and will be available until August 13, 2009.

A replay of the webcast will be also available on the Sonus Networks Investor Relations website. To access the replay of the webcast, visit www.sonusnet.com, About Us, Investor Relations, Webcast Archive.

About Sonus Networks

Sonus Networks, Inc., providing network transformation through IP communications technology, is leading the evolution of communications networks to support the multi-media, multi-device demands of today’s digital lifestyle. Sonus solutions and services enable fixed, mobile and cable operators to gain network awareness and new multi-media capabilities essential to retaining and expanding their subscriber base. Through standards-based interoperable solutions and services, Sonus extends the investments made in traditional networks by enabling operators to seamlessly migrate to next generation technology and deliver the secure, reliable, scalable and cost-effective network needed to grow their business. For more information visit www.sonusnet.com.

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

For more information, please contact:

Sonus Investor Relations:
David Roy / Karin Cellupica
978-614-8353 / 978-614-8615
droy@sonusnet.com
kcellupica@sonusnet.com

Media Relations:
Lucy Millington
978-614-8240
lmillington@sonusnet.com