iBasis Global VoIP Service Wins Internet Telephony Magazine's Product of the Year

The iBasis NetworkTM Called Instrumental in the Growth of IP Telephony

BURLINGTON, MA - December 6, 2001 - iBasis, Inc., (Nasdaq: IBAS), the leader in advanced Internet-based voice communications, today announced that The iBasis Network^TM has been awarded 2001 Product of the Year honors by INTERNET TELEPHONY^® Magazine. Selected based on iBasis' vision, leadership and technological innovation, The iBasis Network is the global VoIP infrastructure for more than 140 carriers, including many of the world's largest Tier 1 carriers - the largest and most demanding carriers in the world.

The iBasis Network has nearly 600 points of presence in over 80 countries. iBasis carries millions of minutes of traditional telecommunications carriers' international voice traffic every day on its global VoIP network. On many of its routes, including its US to China, and US to Russia routes, iBasis has achieved significant market share and carries over 15% of all voice traffic¹.

"We are delighted that INTERNET TELEPHONY chose The iBasis Network for this prestigious award," said Ofer Gneezy, president and CEO of iBasis. "This award recognizes the role of our voice service infrastructure, one of the most advanced Internet telephony networks in the world, in helping to drive the growth of global VoIP traffic, which has doubled in volume over the past year². The shift in global voice traffic from traditional phone networks to the Internet is being driven not only by the inherently superior economics of VoIP transport, but also by the desire of large carriers to outsource international service to more efficient specialist carriers like iBasis who are becoming the `go-to' providers for Tier 1 quality global service."

According to INTERNET TELEPHONY editorial director Greg Galitzine, The iBasis Network was selected because it demonstrates true innovation which is the hallmark of Product of the Year winners. "The Product of the Year award is meant not only to honor the outstanding teams who developed and manufactured the products and services on our winning list, but also to educate our readers on the vast array of offerings in this market. Choosing the winners was a difficult process, and the editorial team spent many hours studying the applications we received from vendors, as well as looking through materials we collected on our own over the past year," said Galitzine.

iBasis and the Move to VoIP
Industry research firm Frost & Sullivan recently predicted that 75% of global voice traffic will be Voice-over-Internet-Protocol (VoIP) by 2007. And while the international voice services market is expected to be worth more than $70 billion, for most large carriers, international service is not a core business, and in many cases represents only about 5% of revenues³. At the same time, the cost of maintaining global service operations is disproportionately high. This is why large carriers continue to outsource increasing amounts of international traffic to efficient, Tier 1 quality VoIP carriers like iBasis.

Outsourcing international traffic to iBasis offers service providers a powerful competitive advantage by lowering the cost of transport and reducing overall global infrastructure requirements. According to industry analyst firm TeleGeography, VoIP transport is expected to account for approximately 6% of all international voice traffic in 2001, double the approximately 3% it represented in 2000. As international voice traffic continues to grow, decreasing sales of traditional circuit-switching equipment, and a predicted tripling of VoIP gateway equipment sales⁴ over the next five years, offers further evidence that the fundamental shift to VoIP is well underway.

iBasis VoIP Service Quality
iBasis guarantees its service quality, offering the industry's first Service Level Agreement (SLA) for VoIP. The key to maintaining the high level of quality required by the world's largest carriers is the company's proven, proprietary Assured Quality RoutingTM (AQRTM) technology. At the company's 24 x 7 Network Operations Centers (NOC) in Burlington, Mass., USA and Hong Kong, the nerve centers of The iBasis Network, engineers continuously monitor the global circuit-switched (PSTN) and packet-switched (IP) networks to ensure the highest quality of service to customers worldwide.

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, Telefonica, Telecom Argentina, Telstra, Sabre Group, Sprint, Western Union, WorldCom, and Verizon. iBasis' hosted, enhanced service solutions include SpeechPort^TM, 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. 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 www.ibasis.com .

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Assured Quality Routing and iBasis are registered trademarks, VoCore is a service mark and iBasis, 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 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.