Sonus Networks Forms China Distribution Partnership with AsiaInfo

Sonus Taps AsiaInfo to Provide Packet Voice Solutions to Chinese Telecom Market; New Reseller Expands Sonus' Reach with Carriers in China

WESTFORD, Mass., March 11, 2002 - Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced that it has formed a distribution relationship with AsiaInfo Holdings, Inc. (Nasdaq: ASIA). Under this non-exclusive agreement, AsiaInfo will provide the full range of Sonus packet voice products to the Chinese carrier market, including Sonus' award-winning GSX9000 Open Services Switch, the Insignus Softswitch and the Sonus Insight Management System. Sonus also today announced that AsiaInfo has joined its Open Services Partner Alliance (OSPA) program.

AsiaInfo is a leading provider of telecom network integration and software solutions in China. The company provides high-quality software and solutions to China's telecom carriers, meeting the demanding needs of a fast-growing industry, through three strategic business units - Network Infrastructure, Operation Support Systems and Service Applications. AsiaInfo's products and services cover network infrastructure services including design, implementation, operation and optimization, customer management and billing solution; decision support system; and service applications encompassing messaging, broadband, wireless and other advanced applications.

AsiaInfo has significant experience in the deployment of carrier-class packet-based infrastructure in mainland China. AsiaInfo has been commissioned to build all of the national IP backbones in China, including ChinaNet for China Telecom, CNCNet for China Netcom, CMCCNet for China Mobile, UniNet for China Unicom and now RailNet for China Railcom.

"We're very pleased to be working with AsiaInfo, who is regarded as a pioneer in the development of IP-based infrastructure in China," said Gary Rogers, vice president, worldwide sales, Sonus Networks. "According to industry watchers, the penetration of voice over IP (VoIP) in China is expected to increase dramatically over the next decade, and our partnerships with companies such as AsiaInfo will help us to attain a leadership position in this market."

The addition of AsiaInfo as a distribution partner and member in the OSPA further strengthens Sonus' presence in China. In December 2001, Sonus launched the company's direct operations in China, establishing a regional office in Beijing. Sonus also recently notched its first customer win in China with China Netcom. China Netcom is building out its nationwide packet voice network on Sonus' voice infrastructure solutions, and plans to leverage the Sonus-based infrastructure to deliver a variety of IP based voice services to enterprise customers.

About AsiaInfo Holdings, Inc.

AsiaInfo Holdings, Inc. (Nasdaq: ASIA) is a leading provider of telecom network integration and software solutions in China. The company provides high-quality software and solutions to China's telecom carriers, meeting the demanding needs of a fast-growing industry.

The company's three strategic business units -- Network Infrastructure, Operation Support Systems and Service Applications -- offer a full-range of front- and back-end telecom software solutions. AsiaInfo's products and services cover network infrastructure services including design, implementation, operation and optimization, customer management and billing solution; decision support system; and service applications encompassing messaging, broadband, wireless and other advanced applications.

A Delaware-registered company, AsiaInfo has constructed national backbones and provincial access networks for all of China's major national telecom carriers since 1995, including China Telecom, China Mobile, China Unicom and China Netcom. Since 2000, the company has successfully shifted its focus from Internet infrastructure construction to the provision of a full suite of telecom software solutions. For more information about AsiaInfo, please visit http://www.asiainfo.com

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 Sonus' Quarterly Report on Form 10-Q, dated November 14, 2001, 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 Company's 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.

GSX9000, Insignus, Sonus Insight and Open Services Architecture are trademarks of Sonus Networks. Open Services Partner Alliance is a service mark of Sonus Networks. All other company and product names may be trademarks of the respective companies with which they are associated.