Sonus' Leading Next Generation Voice Solutions Revolutionize Communications Services

CHELMSFORD, Mass., April 12, 2006 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that the recently issued Gartner “Magic Quadrant for Softswitch Architecture, 2006” report (Bettina Tratz-Ryan, et al, March 29, 2006), which outlines vendors in the IP-based voice industry, positioned Sonus in the “Leader” quadrant.

Sonus is continuing to revolutionize the voice communications industry by delivering the industry's most sophisticated IP Multimedia Subsystem (IMS)-ready architecture, which allows network operators to recognize new operating efficiencies and to change the communications paradigm through the delivery of innovative new services.

“Being positioned in the leader quadrant in Gartner's Magic Quadrant Report is a prestigious honor that we believe confirms Sonus' longstanding position as an innovator with the ability to execute on our vision for this exciting market,” said Hassan Ahmed, chairman and CEO, Sonus Networks. “We are committed to maintaining this coveted position by staying focused on our customers' needs and delivering the solutions that reshape how people think about traditional voice communications.”

Sonus' IMS-ready solutions are currently deployed in some of the world's largest networks and are carrying over 19 billion minutes of traffic per month. Sonus offers a broad portfolio of carrier-class IP-based voice solutions that have penetrated markets around the world and offer carriers a continuous migration path from IP-based voice delivery to multi-service application delivery.

About the Gartner Magic Quadrant

The Magic Quadrant is copyrighted 2006, by Gartner, Inc. and is reused with permission. The Magic Quadrant is a graphical representation of a marketplace at and for a specific time period. It depicts Gartner's analysis of how certain vendors measure against criteria for that marketplace, as defined by Gartner. Gartner does not endorse any vendor, product or service depicted in the Magic Quadrant, and does not advise technology users to select only those vendors placed in the "Leaders" quadrant. The Magic Quadrant is intended solely as a research tool, and is not meant to be a specific guide to action. Gartner disclaims all warranties, express or implied, with respect to this research, including any warranties of merchantability or fitness for a particular purpose.

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, 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. All other company and product names may be trademarks of the respective companies with which they are associated.