Jazztel Connects to iBasis for Global VoIP Services

Leading Competitive Communications Service Provider in Western Europe's Fastest-Growing Telecommunications Markets Selects iBasis for International VoIP

BURLINGTON, MA-January 7, 2002-iBasis, Inc., (Nasdaq: IBAS), the leader in Internet-based voice communications, today announced that Jazztel (Nasdaq, Nasdaq Europe: JAZZ and the Nuevo Mercado in Spain: JAZ), a rapidly growing communications service provider based in Spain and Portugal, has interconnected its service infrastructure to The iBasis NetworkÔ. The interconnection between the two companies enables Jazztel to route its international voice traffic over The iBasis Network - the global VoIP infrastructure for the world's largest carriers. The agreement also allows iBasis to extend its global footprint by terminating its international voice traffic onto Jazztel's extensive network. Spain and Portugal comprise Western Europe's fastest-growing regional market for international voice traffic, with annual growth of 33% and 35% respectively .

Jazztel is a leading communications service provider in Spain and Portugal. Jazztel provides a complete range of voice, data and Internet services through its high-bandwidth network to business customers in Spain and Portugal. Jazztel is the only provider serving the entire Iberian Peninsula that has its own high-capacity fiber optic network offering broadband services.

"Connecting to the fast-growing markets of Spain and Portugal will help us build on our European business, whose revenues and traffic have nearly quadrupled over the past year," said Ofer Gneezy, president and CEO of iBasis. "In response to demand, we are continuing to turn up capacity in our European service facilities, and are well positioned to handle the increasing volumes of international traffic that large carriers in Europe and around the world are outsourcing to efficient global carriers like iBasis."

"As a competitive provider in fast-growing markets, quality is paramount to our success. iBasis offers us great efficiencies in international service with Tier 1 quality service, a combination that helps us preserve our position as the leading competitive carrier in the Spanish and Portuguese markets," said Antonio Carro, CEO at Jazztel.

iBasis in Europe

Today's announcement caps a year of impressive growth for iBasis in Europe. With more than 17 major European carrier customers, iBasis revenues from European voice traffic nearly quadrupled from Q3 2000 to Q3 2001. According to industry analyst publication TeleGeography 2002, Europe has experienced the strongest international traffic growth of any region outside North America, and represented about 43% of all international traffic in 2000, (the latest year for which statistics are available).

Much of the growing demand for iBasis international VoIP services in Europe, as in other regions, has come from Tier 1 carriers, the world's largest and most demanding service providers. More than 50% of all voice traffic carried by The iBasis Network is generated by Tier 1 carriers.

iBasis and the Move to VoIP

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 revenues . At the same time, the cost of maintaining global service operations is disproportionately high. Outsourcing international traffic to iBasis offers service providers a powerful competitive advantage by lowering the cost of transport and reducing overall global infrastructure and service support 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 comprised in 2000. As international voice traffic continues to grow, decreasing sales of traditional circuit-switching equipment and a predicted tripling of VoIP gateway equipment sales over the next five years offers further evidence that the fundamental shift to VoIP is well underway.

About Jazztel

Jazztel p.l.c., (Nasdaq, Nasdaq Europe: JAZZ and the Nuevo Mercado in Spain: JAZ) is a rapidly expanding data and telecommunications operator with activities in Spain and Portugal. The company provides broadband solutions for data, Internet and voice services to small and medium sized businesses in the Iberian Peninsula. Jazztel is currently the only pan Iberian data and telecommunications operator investing in local fiber access networks with broadband capacity. The company is constructing networks in over 150 metropolitan areas and business parks in Spain and Portugal. The access networks, linked by a long-distance network, will constitute one of Europe's fastest data and Internet telecommunication networks with transmission capacity of up to 720 gigabits. The company was founded in 1997 and has over 800 employees. Jazztel also holds nationwide fixed wireless access licenses in Portugal and Spain, in the last case through Banda 26, a subsidiary of the Group. In the first nine months of 2001, Jazztel had total revenues of Euro 164.6 million, 87% more than in the same period in 2000. www.jazztel.com.

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, Telecom Argentina, Telefonica, Telenor, 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. 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 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

1 Based on growth statistics for outbound international voice traffic from Spain and Portugal as published in industry analyst publication TeleGeography 2002.

2 According to Probe Research, 2001

3 According to Wintergreen Research "IP vs. Circuit Switching" August, 2001; and IDC "Standalone VoIP Gateways: Market Analysis" August, 2000.