

	Storm Telecommunications Selects iBasis For Internet Telephony Pan-European Carrier To Route Traffic Over iBasis' Global Network; Provide Termination For iBasis Traffic Across Europe Burlington, Mass.-March 27, 2000-iBasis, Inc., (Nasdaq: IBAS), the leader in advanced Internet-based communications, today announced that it has signed an agreement with UK-headquartered Storm Telecommunications Limited to exchange international voice and fax traffic. As part of this agreement, Storm Telecommunications will route international voice and fax traffic over the iBasis Network™, the world's largest Cisco Powered Network for Internet Telephony, and will terminate international traffic for iBasis into the major business centers of Europe over its high quality, pan-European network. The pan-European Storm Telecommunications voice network is based entirely on International ISDN signaling systems (C7 I-ISUP) and broadband transport systems and offers international, direct-dial termination services to multinational carriers and national and mobile operators. "Storm Telecommunications' technologically advanced infrastructure extends our reach into the important business centers of Europe and ensures the high quality of our international VoIP service," said Charles V. Giambalvo, senior vice president of Worldwide Sales, iBasis. "By linking our extensive European infrastructure to the global iBasis Network, we can provide our customers with high quality, high value international service," said Tom Carroll, Storm's Voice Services Director. 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 NetworkTM is the world's largest international Cisco Powered Network for Internet Telephony. iBasis customers include 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. About Storm Telecommunications Storm Telecommunications, an established voice carrier, is a substantial company with strong revenue growth and operations in 8 countries, and 11 international gateway voice switching hubs. In February 2000, Storm announced its intention to become the first OSP (Optical-switched Service Provider) after Storm's management completed an MBO backed by investment affiliates of Soros Private Equity Partners. This investment allows Storm to launch its new intelligent optical network and places it in prime position to meet the e-business challenges of the new Millennium. 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 8, 2000, and the company's other SEC filings. iBasis, The iBasis Network and Assured Quality Routing are registered trademarks of iBasis, Inc. Cisco and Cisco Powered Network are registered trademarks of Cisco Systems, Inc.