Romania's National Carrier Selects iBasis to Expand Global Service

Romtelecom Connects to The iBasis Network; Extends iBasis VoIP Leadership and Network Footprint in Fast-Growing Southeastern Europe

BURLINGTON, MA -April 29, 2002 -iBasis, Inc. (Nasdaq: IBAS), the leader in Internet-based voice communications, today announced that Romtelecom, the Romanian national carrier, is interconnecting with The iBasis NetworkTM. Romtelecom is connecting to iBasis to quickly expand the reach of its global service. Romtelecom's interconnection to iBasis will enable the national carrier to route its international voice traffic over The iBasis Network and allow iBasis expand its service to Romania using Romtelecom's extensive domestic network.

iBasis in Europe
The relationship highlights iBasis' significant market presence in southeastern Europe - a region predicted to post four-fold growth in VoIP traffic by 2006¹. iBasis has seen strong growth in the region with its voice traffic volumes to and from southeastern Europe increasing by 173% during 2001. Through its carrier relationships, iBasis is able to provide service to several countries in the region including Romania, Bulgaria, Greece, and Slovenia.

More than 44 European carriers are connected to iBasis for international service. These global carriers interconnect to The iBasis Network via the company's many Internet Branch Office facilities in the region, as well as at iBasis' larger, carrier-class Internet Central Office facilities in London, Paris, Frankfurt, and Amsterdam.

Global service providers recently ranked iBasis as the world's #1 international wholesale carrier².

"iBasis leadership as the wholesale provider of choice for many national carriers around the world was a central factor in our decision to connect to The iBasis Network," said Kostas Melitas, Commercial Executive Manager of Romtelecom. "As our nation's leading service provider, we are committed to offering our customers the best and most advanced communications services available. Our interconnection to iBasis will help us deliver Tier One quality and grow our international business - both inbound and outbound - more quickly and efficiently than we could on our own."

"Our relationship with Romtelecom brings the benefits of our high quality global service, which can include higher revenues for providers and better international service for customers, to the growing Romanian market," said Ofer Gneezy, president and CEO of iBasis. "With our traffic volumes now at an annual run rate of more than 2 billion minutes, we are now one the top 15 international carriers in the world³. Romtelecom's selection of iBasis for international service, reflects the trend evident in Europe and elsewhere, as large, national carriers connect to our network to leverage our reliable service and economies of scale."

About Romtelecom
Romtelecom is the leading provider of fixed and mobile telecommunications services in Romania, with the widest portfolio of basic and advanced services that achieve unmatched levels of quality and reliability. Romtelecom's mission is to provide the Romanian market with basic and new telecommunications services. Romtelecom can be found on the Internet at www.romtelecom.ro .

About iBasis
Founded in 1996, iBasis (Nasdaq: IBAS) is the leader in Internet-based voice communications. iBasis delivers toll quality international voice services and provides the infrastructure for hosted communications solutions, including 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, Telefonica, Telenor, Telstra, Sabre Group, Sprint, Western Union, and WorldCom. iBasis' hosted, enhanced service solutions include SpeechPortTM, a scalable, customizable ASP environment for speech-enabled business solutions. The iBasis Network is the world's largest international Cisco Powered Network for Internet Telephony. iBasis is listed in both the Russell 2000® and Russell 3000® Indexes. 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 .

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Assured Quality Routing and iBasis are registered marks, The iBasis Network, Internet Central Office, Internet Branch Office, IP CallCard and SpeechPort 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 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' Annual Report on Form 10-K for its fiscal year ended December 31, 2001, and the company's other SEC filings. We have no current intention to update any forward-looking statements.