Telekom Austria Interconnects with iBasis for International VoIP Services

Leading Carrier in Austria Expands iBasis European Presence

BURLINGTON, MASS. - January 6, 2002 - iBasis, Inc., (OTCBB: IBAS), the leader in Internet-based voice communications, today announced that Telekom Austria, the leading carrier of Austria, is interconnecting with The iBasis NetworkTM for global service. Interconnecting to iBasis will enable Telekom Austria to route international voice traffic over The iBasis Network, the world's largest Cisco Powered Network for Internet telephony, as well as complete calls for iBasis in markets served by Telekom Austria's network.

Telekom Austria joins the more than 160 carriers worldwide who have formed partnerships with iBasis. By providing Tier One quality international service to these carriers, iBasis has become one of the world's 10 largest carriers of international traffic¹ and was recently ranked by global service providers as the world's #1 international wholesale carrier².

"Telekom Austria has always been a leader in leveraging technological advances to provide beneficial services for our customers. Interconnecting with iBasis enables us to enhance our international service options very efficiently," said Josef Trimmel, Head of Wholesale for Telekom Austria. "iBasis shares our commitment to quality and enables us to expand our global communications footprint quickly and cost efficiently."

"While much of the telecommunications industry continues to struggle, iBasis and the international VoIP segment as a whole continues to experience significant growth in customer demand," said Ofer Gneezy, president and CEO of iBasis. "The high concentration of Tier One carriers like Telekom Austria among our customers is evidence of the quality of the service we provide and the compelling value proposition we deliver. Like many other large national carriers, Telekom Austria is able to leverage our many carrier relationships around the world to meet its international service requirements while focusing on its successful and growing domestic and regional businesses."

About Telekom Austria

The Telekom Austria Group is the largest telecommunications group in Austria, with total managed revenues of more than 3.9 billion Euros and headcount of more than 16,000 at the end of December 2001. The Group is the leading provider in Austria in four main strategic business segments: Fixed Line, Mobile Communications, Data Communications, and Internet services. Telekom Austria also has international operations in Liechtenstein, Croatia, Slovenia and the Czech Republic in the Internet and mobile communications business. With almost 3.2 million lines, Telekom Austria's fully digital network infrastructure provides blanket coverage for all of Austria. In addition, Telekom Austria is the leading provider of fixed line services for other operators in Austria. Additional products and services include value added services, call management, coin and prepaid card telephony, call centers, sales of equipment and the publication of telephone books through Herold Business Data AG.

About iBasis

Founded in 1996, iBasis (OTCBB: IBAS) is a leading provider of wholesale international telecommunications services. 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 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.

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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.