Armstrong Chooses Sonus Networks for SIP Core and Border Security

Deployment Enables IP Trunking, IP Peering, and Migration to PacketCable 2.0

Westford, Mass., September 28, 2010 – Sonus Networks, Inc. (Nasdaq: SONS), a market leader in next-generation IP-based network solutions, today announced that Armstrong Cable, one of North America's oldest independent cable providers, will deploy a Sonus Class 4 VoIP core for a significant network migration project.

Armstrong was seeking a vendor to help build a SIP core for its telecom network. The Sonus solution will provide IP trunking and add session border control capabilities to enable VoIP Peering. This new SIP core will also allow Armstrong to develop a longer-term strategy to migrate their telephony network to IMS and PacketCable 2.0TM . Armstrong purchased the Sonus NBS-9000 Network Border Switch for session border control and media transcoding, the GSX 9000 High-Density Media Gateway, and the PSX Centralized Routing and Policy Server to make this strategic change to their Class 4 VoIP network.

"We selected Sonus Networks because we wanted a solution from a single vendor that would provide immediate economic benefits and enable our infrastructure to deliver new voice services to our customers in the coming years," said Mike Giobbi, CTO of Armstrong. "We wanted the option of migrating to PacketCable 2.0 while leveraging a common management platform. Sonus has the technology and stability we need to move our business forward and continue to exceed our customers' expectations."

Armstrong has a rich history of leading the industry in technology and innovation, beginning with nine channels of video in 1963 to offering a full spectrum of services, including advanced Television, Telephone, and Internet today. Along the way they pioneered many industry standards. Armstrong was an early entrant in the broadband business and is now leading the way with innovative Fiber to The Home design and implementation.

"Leading cable providers like Armstrong are advancing their telecom networks to embrace SIP and IMS so they can lower the cost of serving their growing customer bases," said Guru Pai, chief operating officer at Sonus Networks. "Sonus products deliver a compelling ROI and enhance both the core infrastructure and the customer experience for our cable provider customers worldwide."

About Armstrong

Armstrong Utilities, Inc . provides Television, Telephone, and InternetSee broadband. services to customers in Pennsylvania, Ohio, Maryland, West Virginia and Kentucky. The company is presently the 16th largest cable television provider in the United States, according to Kagan World Media. For more information about Armstrong's products and services, please visit www.armstrongonewire.com

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. For more information, visit www.sonus.net.

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, 2009 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:

Sonus Networks:
Aline Kaplan
alkaplan@sonusnet.com
+1 978-614-8167

Paul Roberts
sonus@daviesmurphy.com
+1 781-418-2418

Armstrong
Mike Giobbi, CTO
mgiobbi@agoc.com
Phone: +1 724-283-0925