Sonus Networks-Based IP Voice Traffic Reaches New Record

CHELMSFORD, Mass., July 24 2006 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that according to a report entitled, “VoIP Minutes and Subscribers: 1Q06 Update,” issued by iLocus, 32% of all long distance IP-based voice traffic is carried over Sonus Networks' IP Multimedia Subsystem (IMS)-ready networks. In the second quarter of 2006, Sonus solutions drove nearly 61 billion minutes of IP voice traffic. In the month of June alone, Sonus-based networks carried 22 billion minutes of IP voice traffic, representing a nearly 70% increase compared to June 2005. The dramatic growth in traffic is attributable to a combination of factors including a number of new Sonus customers bringing their networks live, as well as the decision by major incumbent network operators to migrate more of their traffic from their traditional network infrastructures onto their Sonus-based network.

“The growth in the amount of voice traffic that Sonus-based voice networks carry is truly impressive, as it demonstrates not only the success of the company and the strength of Sonus' technology, but also the increased comfort levels of network operators to migrate their traffic to next generation platforms,” said Jahangir Raina, Director, iLocus. “Sonus has really set the standard in terms of reliability and scalability that network operators should expect from their equipment provider.”

Sonus' award winning IMS-ready architecture is relied upon by network operators globally, and today, Sonus solutions form the foundation of some of the largest and most sophisticated IP-based voice networks in the world. Sonus' distributed architecture enables carriers to scale their infrastructure, penetrate new markets and expand their revenue opportunity by supporting the introduction of innovative new applications and services. The iLocus report recognized that Sonus leads both the national and international long distance market with 33% and 24% of voice traffic respectively. With nearly a third of all IP-based voice traffic running on Sonus-based networks, Sonus carries approximately 2.5 times traffic more than any other vendor.

“Sonus solutions form the foundation of some of the world's most exciting voice networks. We have successfully partnered with innovative network operators that are committed to leveraging the benefits of an IMS-ready architecture to drive operating leverage and deliver unparalleled value to their customers,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “The market for IP-voice communications is approaching an important inflection point, as major network operators around the globe unveil their plans for IP-based voice architectures. Each quarter, the minutes of use carried on Sonus networks continues to rise, which demonstrates the confidence our customers have in a network with Sonus technology at its foundation.”

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 comprehensive IP Multimedia Subsystem (IMS) solution, Sonus addresses the full range of carrier applications, including residential and business voice services, wireless voice and multimedia, trunking and tandem switching, carrier interconnection and enhanced services. Sonus' voice infrastructure solutions are deployed in service provider networks worldwide. Founded in 1997, Sonus is headquartered in Chelmsford, Massachusetts. Additional information on Sonus is available at 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. Readers are referred to the “Risk Factors” section of Sonus' Annual Report on Form 10-K, dated March 14, 2006 and Quarterly Report on Form 10-Q, dated May 8, 2006, both filed with the SEC, which identify important risk factors that could cause actual results to differ from those contained in the forward-looking statements. Risk factors include among others: the impact of material weaknesses in our disclosure controls and procedures and our internal control over financial reporting on our ability to report our financial results timely and accurately; the unpredictability of our quarterly financial results; risks associated with our international expansion and growth; consolidation in the telecommunications industry; and potential costs resulting from pending securities litigation against the company. 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.

Sonus is a registered trademark of Sonus Networks, Inc. Sonus GSX9000 Open Services Switch, PSX Call Routing Server, SGX Signaling Gateway, and the Sonus Insight Management System are trademarks of Sonus Networks, Inc. All other company and product names may be trademarks of the respective companies with which they are associated.