iBasis Adds Former IBM, Lotus Senior Executive
to Board of Directors

W. Frank King, Brings Substantial Tech Industry Experience to iBasis Board

BURLINGTON, Mass.- June 26, 2001 - iBasis, Inc., (Nasdaq: IBAS) today announced that W. Frank King will join its Board of Directors.

Dr. King, 61, has held senior executive positions at industry-leading technology companies, including IBM, where his last position was Vice President of the Entry Systems Division, and Lotus Development Corp., where as Senior Vice President of Development he was responsible for the company's suite of PC-based software applications. From 1992 to 1998 Dr. King was CEO and a Director of Concero, Inc., formerly PSW Technologies, Inc., an e-business services firm. Dr. King currently serves on the Board of Directors of aleri inc., eOn Communications Corp., Concero, NMS Communications Corp. (formerly Natural MicroSystems), and Perficient, Inc. King earned his Ph.D. in electrical engineering from Princeton University and holds a master's degree in electrical engineering from Stanford University and a bachelor's degree in electrical engineering from the University of Florida.

"Dr. King is a highly respected, experienced leader in the technology industry," said Ofer Gneezy, president and CEO of iBasis. "His extensive and impressive record of achievement combined with his deep technological expertise makes him an outstanding addition to our Board of Directors."

With the appointment of Dr. King as a Class II Director, the iBasis Board of Directors continues to have seven members, including five outside directors and the company's two co-founders.

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 Network 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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