China Netcom Agreement Extends iBasis Leadership in Asia

Enables Major Chinese Carrier to Route Worldwide Voice and Fax Traffic over the iBasis Network; Links iBasis to CNC's Rapidly Growing, Next Generation Services

BURLINGTON, Mass., July 10, 2000-iBasis, Inc, (Nasdaq: IBAS), the leader in advanced Internet-based communications, today announced that China Netcom Corporation Ltd., (China Netcom or CNC,) is the fourth major Chinese carrier to have selected the iBasis Network™ for global Internet Telephony. Under the terms of the agreement, China Netcom will be able to route international voice and fax calls over the global iBasis Network, the world's largest international Cisco Powered Network for Internet Telephony. The agreement also further extends iBasis' already significant footprint in China by enabling termination of iBasis traffic onto China Netcom's network.

China Netcom, China's third fully licensed telecommunications carrier, was established in 1999 with investments from the Chinese Academy of Science, the Ministry of Railways, the State Administration at Radio, Film and Television and the Shanghai Municipal Government. China Netcom is a rapidly growing, next generation carrier that provides open, IP-based communications services that integrate voice, video, fax and data. China Netcom has recently deployed CNCnet - a fiber-optic, IP over DWDM (Dense Wave Division Multiplexing) backbone network, which covers 17 cities in Southeast China.

"In the new information economy, it is essential that China build a world-class telecommunications infrastructure based on the latest communications innovations," said Edward S. Tian, China Netcom's chief executive officer. "China Netcom's choice of iBasis for Internet telephony was driven by their unmatched expertise in international VoIP, extensive global footprint and proven, carrier-grade quality of service."

The China Netcom/iBasis partnership adds to the growing list of leading Asian carriers already routing traffic over the iBasis Network, including China Mobile, the world's largest wireless provider, China Unicom, China's second largest carrier, JITONG Communications, China's third largest carrier, NTT, Japan's national carrier, Telstra, the national carrier in Australia and The Communications Authority of Thailand, that country's national carrier. Frost & Sullivan predicts that the Asian IP voice market will be worth $48 billion by 2006.

"With four of the largest Chinese carriers as customers, China is an important and fast-growing market for iBasis. Our continued success in China enabled us to increase our overall China traffic during the second quarter by more than 65 percent over first quarter volume," said Ofer Gneezy, president and CEO of iBasis. "Our partnership with China Netcom aligns us with a rapidly-growing regional and global communications leader and highlights the central role of IP-based services in China's communications growth strategy.

The iBasis Network 
The iBasis Network is the world's largest international Cisco Powered Network (CPN) for Internet telephony. iBasis is the only Internet telephony carrier that guarantees service quality by offering the industry's first Service Level Agreement (SLA) for VoIP (Voice-over-Internet-Protocol). The key to maintaining the high level of quality required by the world's largest carriers is the company's proven, proprietary Assured Quality Routing™ (AQR™) technology. At the company's 24 x 7 Network Operations Center (NOC), the nerve center of The iBasis Network, located at iBasis' global headquarters in Burlington, Massachusetts, USA, engineers continuously monitor the global circuit-switched (PSTN) and packet-switched (IP) networks to ensure the highest quality of service to customers worldwide.

iBasis has a long-standing strategic relationship with Cisco, as an alliance partner, an ecosystem partner, and one of only 21 Cisco service provider global accounts.

About China Netcom Corporation Ltd. 
China Netcom Corporation Ltd. (CNC) was established in August 1999 with investments from the Chinese Academy of Science, the Ministry of Railways, the State Administration at Radio, Film and Television and the Shanghai Municipal Government. CNC has been created to build a new generation of telecommunications infrastructure. It will provide a full range of telecommunications services through CNCnet, which will initially cover l7 cities in China, including Beijing, Tianjin, Jinan, Ningbo, Hefei, Nanchang, Naniing, Shanghai, Hangzhou, Fuzhbou, Xiamen, Cuangzhou, Shenzhen, Changsha, Wuhan, Zhengzhou and Shijiazhuang.

CNC represents a new generation of state-owned telecommunications enterprise in China. The Company has a high standard of corporate governance, with a clear delineation made between ownership and operation. CNC's management and employees share a common determination to achieve the Company's vision of building a telecommunications network for the next generation.

About iBasis 
Founded in 1996, iBasis (Nasdaq: IBAS) is the leader in advanced Internet-based communications. iBasis has built the world's first global IP network that delivers toll quality voice and fax service and other advanced hosted communications solutions, including VoCore, to global tier one carriers and other service providers. The iBasis Network is the world's largest international Cisco Powered Network for Internet telephony. More than 70 international carriers are iBasis customers, including 11 of the top 12 US international carriers. The company can be reached at its worldwide headquarters in Burlington, Mass., USA at 781-505-7500 or on the Internet at www.ibasis.net.

Except for historical information, all of the expectations, projections and assumptions contained in the foregoing press release constitute forward-looking statements under the Private Securities Litigation Reform Act of 1995 and involve risks and uncertainties. Important factors that could cause actual results to differ materially from such forward-looking statements include, but are not limited to, the considerations described as "Risk Factors" in iBasis' prospectus dated March 9, 2000, and the company's other SEC filings.

Assured Quality Routing is a registered trademark and iBasis and The iBasis Network are trademarks of iBasis, Inc. Cisco and Cisco Powered Network are registered trademarks of Cisco Systems, Inc.