WESTFORD, Mass., April 14, 2009 – Sonus Networks Inc. (Nasdaq: SONS), providing network transformation through IP communications technology, today announced that it will release financial results for the first quarter 2009 prior to opening of the market on Tuesday, May 5, 2009, and will host a conference call with financial analysts and investors at 10:00 a.m. ET that day.

To listen via telephone:

Dial-in number: 800-908-8951
International Callers: +1 212-231-2902

To listen via the 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 21421887, and will be available until May 19, 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.

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 http://www.sonusnet.com.

This release may contain forward-looking statements regarding future events 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. For a discussion of the risks and uncertainties which could cause actual results to differ from those contained in the forward-looking statements, see “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2008. Risk factors include among others: the unpredictability of our quarterly financial results; risks and uncertainties associated with the Company's previous restatement of its historical stock option granting practices and accounting including regulatory actions; actions that may be taken by significant shareholders; risks associated with our international expansion; and the impact the current global financial market conditions may have on the telecommunications industry. Any forward-looking statements represent Sonus' views only as of today and should not be relied upon as representing Sonus' views as of any subsequent date. While Sonus may elect to update forward-looking statements at some point, Sonus specifically disclaims any obligation to do so, except as required by law.

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:

Media Relations:
Lucy Millington
1-978-614-8240
lmillington@sonusnet.com

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