Sonus Solutions Support International Wholesale VoIP Services, Enable AIH to Expand Product Portfolio 

WESTFORD, Mass., June 23, 2003  – Sonus Networks (Nasdaq: SONS) today announced that Asia Internet Holding Co. Ltd. (AIH) has deployed Sonus' Open Services Architecture (OSA) and voice infrastructure solutions to deliver wholesale voice over IP (VoIP) services to telecommunications service providers and carriers in the Asia Pacific region. AIH recently announced that it will begin offering its "A-Bone VoIP Service" on June 23.

"By implementing a carrier-grade, next-generation VoIP infrastructure, AIH is able to broaden the portfolio of services it offers customers and attack new revenue opportunities," said Michael O'Hara, vice president, marketing, Sonus Networks. "AIH has delivered data services over its advanced, highly engineered Internet backbone for years, so providing VoIP services on that foundation is a logical next step for the company. We are pleased to be working with AIH to further the adoption of VoIP in the Asia Pacific region and throughout the world."

In 1995, AIH constructed the "A-Bone", an Internet backbone network covering the Asia Pacific region, and began operation of the network in 1996. The A-Bone provides direct connections to Asia Pacific countries, and also transports traffic to the United States, Europe and other areas of the world. The A-Bone offers high-speed, high-quality Internet access services for corporate users and Internet Service Providers (ISPs) located throughout the region. In addition to Internet connectivity services, AIH provides virtual private network (VPN) services to enterprises.

To expand its service offerings, AIH has deployed Sonus' GSX9000 Open Services Switch, the Insignus Softswitch and the Sonus Insight Management System. With the Sonus infrastructure in place, AIH will offer wholesale VoIP services to service providers and carriers in the region. Customers using the new A-Bone VoIP service will be able to provide cost-effective, high-quality voice services to enterprise and consumer users. Additionally, AIH is planning to leverage the Sonus systems to offer VoIP services directly to enterprise customers in Japan.  

About AIH

Asia Internet Holding Co., Ltd. (AIH) was established in 1995 to construct and operate "A-Bone", the Internet backbone network covering the Asia Pacific region. A-Bone directly links countries in the region with high-speed and large-capacity circuits, which enables intra-Asian information traffic to be routed effectively. AIH is supported by shareholders in the region such as Internet Initiative Japan (IIJ, Nasdaq: IIJI; shareholding ratio: 26.69%), Sumitomo Corporation (31.61%) NTT Communications, Itochu Corporation, Telekom Malaysia and Communications Authority of Thailand.

About Sonus Networks

Sonus Networks, Inc., is a leading provider of packet voice infrastructure products for the new public network. With its Open Services Architecture (OSA), Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking, residential access and Centrex, tandem switching, and IP voice termination, as well as enhanced services. Sonus' award-winning voice infrastructure solutions, including media gateways, softswitches and network management systems, are deployed in service provider networks worldwide. Sonus, founded in 1997, is headquartered in Westford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

This release may contain projections or other forward-looking statements regarding future events or the future financial performance of Sonus 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 19, 2003 and filed with the SEC, which identifies important risk factors that could cause actual results to differ from those contained in the forward-looking statements. These risk factors include, among others, the adverse effect of recent developments in the telecommunications industry, the weakened financial position of many service providers, Sonus' ability to grow its customer base, dependence on new product offerings, market acceptance of its products, rapid technological and market change and manufacturing and sourcing risks. In addition, 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. Open Services Architecture, GSX9000, Insignus and Sonus Insight are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.