Sonus Experts Present at Expo Comm Wireless Japan; New Applications Demonstrated at VON Japan

CHELMSFORD, Mass., July 11, 2006 – Sonus Networks (Nasdaq: SONS), a leading supplier of service provider Voice over IP (VoIP) infrastructure solutions, announced today that it will be showcasing its industry leading IP Multimedia Subsystem (IMS)-based solutions at this year's VON Japan (Booth V-001), which is being held in Tokyo, July 19-21, 2006 at Tokyo Big Sight International Exhibition Center. In addition to Sonus' presence in the exhibit hall, executives from the company will be presenting at Expo Comm Wireless Japan. Co-located with VON Japan 2006, Expo Comm Wireless is Japan's largest wireless conference.

With many of Japan's leading service providers relying on solutions from Sonus Networks, including KDDI, Fusion Communications, Jupiter Communications (J:COM), NTT, Softbank Broadband and WILLCOM, Inc., Sonus is leading the Japanese market's transition to IP-based voice solutions. According to recent reports by industry research firm Synergy Research Group, at the end of Q1, Sonus led the market with 45% of the total Japanese service provider VoIP infrastructure market, more than 6x its nearest competitor. In the high density gateway market specifically, Sonus leads the industry with nearly 87% of the total market.

Sonus will be demonstrating how its solutions are transforming the communications paradigm through enhanced, next generation voice services that can be delivered today over a Sonus IMS-ready architecture. These applications, built with Sonus' IMS application development tools, including the Sonus IMX™ Multimedia Application Platform, help service providers to attract and retain new customers, and differentiate themselves through innovative service bundles.

Leveraging the Company's expertise in the development and evolution of the industry's leading IMS-ready solutions, Sonus' chief marketing officer, Steve Edwards, will be delivering a keynote entitled, “IMS: The Path Forward” as part of the Expo Comm Wireless program.

Friday, July 21, 2006, 10:00 - 10:45 am
Session: Keynote Presentation: IMS: The Path Forward
Speaker: Steve Edwards, Chief Marketing Officer

In addition to the keynote presentation, Sonus will be participating in the following technical session:

Wednesday, July 19, 2006, 11:00 - 11:45 am
Session: Content Delivery in the all IP Wireless Network
Speaker: Shigetoshi Amano

Pulver.com's VON Japan 2006 conference and Expo Comm Wireless begin on Wednesday, July 19, 2006. All events will be held at the Tokyo Big Sight International Exhibition Center.

For more information on VON Japan 2006, please visit http://www.von.com/japan06/. For more information on Expo Comm Wireless, please visit http://www.expocomm.com/wirelessjapan/index.html.

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