iBasis Names Richard Tennant Chief Financial Officer

Industry Veteran Brings Financial Expertise, Experience in High Technology to Voice Services Provider

BURLINGTON, MA - October 25, 2001 - iBasis, Inc., (Nasdaq:IBAS), the leader in advanced Internet-based communications, today announced the appointment of Richard Tennant as vice president, Finance and Administration and Chief Financial Officer. Tennant is assuming the responsibilities of managing the company's Finance organization from interim Chief Financial Officer D.J. Long, who continues to serve as vice president of Corporate Development.

"At a time when we are totally focused on moving aggressively toward profitability, Dick Tennant, with his depth of experience in corporate finance, is a powerful addition to our senior management team," said Ofer Gneezy, president and CEO of iBasis. "Dick has a proven track record of delivering strong results and efficiently managing growth for large public companies, such as LTX and Netrix. We are delighted to have him aboard."

Tennant's responsibilities include helping to shape and drive the company's business strategy, and overseeing the financial management of the company. Tennant reports directly to iBasis President and CEO Ofer Gneezy.

Tennant has more than 20 years of experience in corporate finance and administration. Prior to joining iBasis, he was vice president, CFO and treasurer for ScoreBoard, a software start-up company targeting the wireless carrier market. Previously, Tennant served as CFO of several private and public companies, including LTX Corporation, a semiconductor testing solutions vendor with annual revenues of more than $200 million. Tennant also served as CFO for Netrix Corporation, a telecom equipment and software manufacturer.

"iBasis is a dynamic company in a huge and growing market," said Richard Tennant. "I am looking forward to helping iBasis reach the next great milestone in its development - profitability."

About iBasis
Founded in 1996, iBasis (Nasdaq: IBAS) is the leader in advanced Internet-based voice communications. iBasis delivers toll quality international voice services and provides the infrastructure for hosted communications solutions, including messaging and speech-enabled content, e-commerce and customer service applications. The company's customers include many of the largest enterprises and carriers in the world, including AT&T, Cable & Wireless, China Mobile, China Unicom, Concert, ExxonMobil, Gannett, H&R Block, Home Shopping Network, Morgan Stanley, NTT, Telstra, Sabre Group, Sprint, Western Union, WorldCom, and Verizon. iBasis' hosted, enhanced service solutions include SpeechPortTM, a scalable, customizable ASP environment for speech-enabled business solutions, VoCore^SM messaging and the IP CallCardTM pre- and post-paid calling card platform. The iBasis NetworkTM is the world's largest international Cisco Powered Network for Internet Telephony and the first to receive the Unified Communications-Cisco Powered Network (UC-CPN) designation. iBasis is listed in both the Russell 2000® and Russell 3000® Indexes. The company can be reached at its worldwide headquarters in Burlington, Mass., USA at 781-505-7500 or on the Internet at http://www.ibasis.com .

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Assured Quality Routing and iBasis are registered marks, VoCore is a service mark, The iBasis Network, Internet Central Office, Internet Branch Office, IP CallCard, SpeechPort, IPort, and PriceInteractive are trademarks of iBasis, Inc. or its subsidiaries. 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 new voice-based Internet services and the timing and amount of revenue generated by these services; (ii) fluctuations in the market for and pricing of VoIP services; and (iii) the other considerations described as "Risk Factors" in iBasis' Annual Report on Form 10-K for its fiscal year ended December 31, 2000, and the company's other SEC filings.