First Member Joins Sonus' Recently Launched Interoperability Certification Program

CHELMSFORD, Mass., October 19, 2006 – Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced that in the Company's ongoing efforts to expand network operator access to IP Multimedia Subsystem (IMS)-ready applications and services, Soleo Communications is the first member to join Sonus' recently launched Interoperability Certification Program, part of Sonus' Open Services Partner Alliance (OSPA). As the industry's market leader in the IP-based voice market, carrying more than 3x the number of IP voice minutes than any other equipment provider according to iLocus Research, Sonus continues to drive interoperability initiatives across the industry in order to help network operators recognize the benefits of IMS-ready applications and services through a more robust communications experience.

"In order for IP-based voice services to reach critical mass, the different players in the industry must collaborate to ensure seamless interoperability of their products and services. Sonus has taken a leadership role on this front by augmenting its OSPA with the Interoperability Certification Program," said Steve Edwards, Chief Marketing Officer, Sonus Networks. "Soleo Communications offers a valuable service to network operators, and we're pleased they have chosen to become the first member to take advantage of the extensive testing capabilities the new program offers."

The Sonus Interoperability Certification Program leverages the University of New Hampshire InterOperability Lab (UNH-IOL) to conduct extensive testing and streamline the delivery of Session Initiation Protocol (SIP)-based products and services into the rapidly evolving IP-based voice market. As the flagship partner in the Sonus Certification Program, Soleo's Service Request Platform, a robust, standards-based VoIP framework that delivers automated agent and subscriber services, will be integrated with Sonus' complete IMS-ready network architecture. The Soleo Service Request Platform enables network operators to easily introduce new services, and integrates traditional and next generation networks using the same gateway infrastructure. As a result, Soleo's open, scalable framework delivers immediate benefits while allowing customers to seamlessly migrate from legacy technologies to evolving IMS standards.

"The Soleo Service Request Platform allows service providers to seamlessly support migration to next-generation networks, such as IMS. With extensive customer deployments underway with leading network operators around the world, Sonus is at the forefront of the IMS industry, and ensuring our products interoperate seamlessly is critical to our success in these dynamic networks," said Nicholas Costantino, Director, Product Management & Business Development, Soleo Communications.

"We're excited to begin testing Soleo's Service Request Platform and help Sonus work towards its goal of expanding network operator access to new services," said Timothy Winters, UNH-IOL Software Managing Engineer. "The UNH InterOperability Lab has significant resources and expertise, streamlining the testing process and helping a fully integrated solution get to market faster."

The Sonus Open Services Partner Alliance (OSPA) is the industry's largest interoperability program, helping to keep service providers at the forefront of innovation. The OSPA creates strategic partnerships with best-in-class telecom applications and infrastructure companies. Partner products are integrated and tested with the Sonus IMS-ready architecture promoting deployments that are more rapid and reliable. By anticipating technology and market trends, the OSPA helps service providers introduce new services and exploit emerging technologies quickly and confidently.

About Soleo

Soleo Communications, Inc. provides a complete portfolio of platforms, applications, and professional services to Directory & Operator Services Providers. We adhere to carrier-grade standards for all components in our service offering. Please contact Nick Costantino at ncostantino@soleocommunications.com for more information.

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' Quarterly Report on Form 10-Q, dated May 8, 2006, filed with the SEC, which identifies 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 and uncertainties associated with the Company's announced review of its historical stock option grants and accounting, including any potential impact of the Company's financial statements or results, the Company's inability to timely report with the Securities and Exchange Commission, the Company's potential inability to meet NASDAQ requirements for continued listing, potential investigations or litigation arising out of the review or any restatement; 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.