iBasis Carries Five Billionth Minute of VoIP Traffic over its International Cisco Powered Network

Completed "Next Generation" Switchless Architecture Deployment Delivers High Voice Quality, Low-cost Network Expansion

BURLINGTON, MASS. - February 18, 2003 - iBasis, Inc. (OTCBB: IBAS), the leader in Internet-based voice communications, today announced that it recently surpassed the five billionth minute of voice traffic carried over The iBasis NetworkTM, the world's largest international Cisco Powered NetworkTM for Internet telephony.

The iBasis Network has been carrying VoIP traffic for Tier One carriers and other international service providers since 1998. In 2002 the company completed the deployment of its next generation switchless architecture, leveraging its existing Cisco AS5000 gateways and SC 2200 SS7 technology, as well as new patent-pending iBasis technology for quality management and advanced routing.

The company's investment in its next generation network and proprietary systems helped iBasis achieve the ranking of #1 International Wholesale Carrier, with network voice quality and code coverage second only to AT&T, in the 2003 Wholesale Carrier Report Card study by industry research and advisory firm Atlantic-ACM. (For detail on the Atlantic-ACM study see separate iBasis announcement released today.)

"Now in our fourth year as a Cisco Powered Network, we have hundreds of staff-years of expertise in deploying and managing a global voice network based on those platforms and in developing and integrating the proprietary technology required to manage voice traffic over the public Internet and deliver very high quality service," said Ofer Gneezy, president and CEO of iBasis.

"Moreover, we have successfully integrated enhanced network services such as our IP CallCard hosted billing platform for pre-paid operators and ConnectPoint Global Access for audioconferencing, pre-paid and call center providers. These services leverage the same global network infrastructure as our core wholesale call completion service. Along with our core service and our interoperability with other key VoIP vendors such as VocalTec, they are enabling iBasis to make substantial progress towards profitability and the next five billion minutes."

The iBasis Network
The iBasis NetworkTM is the world's largest international Cisco Powered Network for Internet telephony, with more than 770 points of presence in approximately 90 countries. In 2002 the company completed the deployment of its next generation switchless architecture, leveraging its existing Cisco AS5000 gateways and SC 2200 SS7 technology, as well as new patent-pending iBasis technology for quality management and advanced routing. The company's Assured Quality Routing^® and PathEngineTM technology enable ongoing monitoring of network quality and automatic selection of best quality routes based on near real-time performance data. The result for iBasis customers is higher voice quality, call completion and call duration.

About iBasis
Founded in 1996, iBasis (OTCBB: IBAS) is a leading provider of wholesale international telecommunications services to large carriers and other service providers worldwide. Named by service providers as the #1 international wholesale carrier in Atlantic-ACM's 2002 International Wholesale Carrier Report Card, iBasis is a preferred provider of international voice services for many of the largest carriers in the world, including AT&T, Cable & Wireless, China Mobile, China Unicom, Sprint, Telefonica, Telenor, Telstra, and WorldCom. The company's global VoIP infrastructure, The iBasis Network, spans more than 90 on-net countries and is the world's largest international Cisco Powered NetworkTM for Internet Telephony. Based on its revenue growth from 1997 through 2001, iBasis was named the #8 fastest-growing technology company in North America and the #1 fastest-growing technology company in New England in the Technology Fast 500 national program sponsored by Deloitte & Touche. The company can be reached at its worldwide headquarters in Burlington, Massachusetts, USA at 781-505-7500 or on the Internet at www.ibasis.com.

###

Assured Quality Routing and iBasis are registered marks, The iBasis Network, Internet Central Office, Internet Branch Office, ConnectPoint Global Access, and IP CallCard are trademarks of iBasis, Inc. Cisco and Cisco Powered Network are registered trademarks of Cisco Systems, Inc. All other trademarks are the property of their respective owners.

Except for historical information, all of the expectations, projections and assumptions contained in the foregoing press release, including those relating to the company's current expectations regarding revenue growth, sources of revenue, margin improvement and future capital expenditures 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, (i) the extent of adoption of the company's services and the timing and amount of revenue generated by these services; (ii) fluctuations in the market for and pricing of these services; and (iii) the other considerations described as "Risk Factors" in iBasis' most recent Forms 10-K and 10-Q, and the company's other SEC filings. We have no current intention to update any forward-looking statements.