Sonus Networks to Host Investor Day in New York City on June 9, 2011

Westford, MA, June 1, 2011 – Sonus Networks, Inc. (Nasdaq: SONS), a market leader in next-generation IP-based network solutions , today announced that it is hosting an Investor Day on June 9, 2011 beginning at 9:00 a.m. at the New York Palace Hotel in Manhattan. Raymond P. Dolan, the Company's President and Chief Executive Officer, along with other members of the executive team, will provide investors and analysts with insight into the Company's strategy, differentiation and growth opportunities. The agenda will also include extended opportunities for shared dialog and Q&A.

Questions may be submitted in advance to IR@sonusnet.com. Pre-registration is required and should be completed by Friday, June 3, 2011 at: http://bit.ly/j8XOw8 .

All interested parties can access the webcast live on the Company's investor relations website at http://www.investors.sonusnet.com/events.cfm . The webcast will be archived on the Company's website for sixty days following the presentation .

About Sonus Networks

Sonus Networks, Inc. is a leader in IP networking with proven expertise in delivering secure, reliable and scalable next-generation infrastructure and subscriber solutions. With customers in over 50 countries across the globe and over a decade of experience in transforming networks to IP, Sonus has enabled service providers and enterprises to capture and retain users and generate significant ROI. Sonus products include media and signaling gateways, policy/routing servers, session border controllers and subscriber feature servers. Sonus products are supported by a global services team with experience in design, deployment and maintenance of some of the world's largest and most complex IP networks. Visit http://www.investors.sonusnet.com for more information about Sonus Networks.

Important Information Regarding Forward-Looking Statements

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. Readers are referred to Item 1A "Risk Factors" of Sonus' Annual Report on Form 10-K for the year ended December 31, 2010 and all subsequent Quarterly Reports on Form 10-Q, which identify important risk factors that could cause actual results to differ from those contained in the forward-looking statements. 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:

Wayne Pastore
978-614-8291
wpastore@sonusnet.com

Fran Murphy
978-614-8148
fmurphy@sonusnet.com