iBasis Reaches Agreement to Sell Messaging Business to Call Sciences

Sale Enhances Drive to Profitability and Focus on Core Business

BURLINGTON, MA - February 14, 2002 - iBasis, Inc., (Nasdaq: IBAS), the leader in Internet-based voice communications, today announced that it has signed a definitive agreement to sell its Messaging line of business to Call Sciences, an enhanced communications service provider.

Financial terms of the transaction were not disclosed. The transaction is expected to close within thirty days subject to certain conditions.

Under the agreement, iBasis will sell to Call Sciences, an international corporation that develops and markets unified communications solutions, all of its Messaging service business, including its Santa Clara, California data center, its customers, revenue streams, and customer prospects related to the Messaging line of business. The sale includes the company's VoCore^SM hosted messaging solution for wireless and wireline carriers. VoCore is a comprehensive portfolio of hosted, communications services, including phone-based access to email, voicemail, and faxmail, PIM (integrated personal scheduling and contact management), and personalized communications portal services.

"Our employees did a fantastic job over the past year in enhancing the VoCore platform," said Ofer Gneezy, president and CEO of iBasis. "Ultimately, we decided that our drive to profitability will be better served by focusing our resources on our rapidly growing Internet Telephony line of business and our Speech Solutions business. Call Sciences is an established leader in the messaging services field and a natural fit for this business."

"We are very pleased to have reached agreement with iBasis to acquire their Messaging line of business. This is an outstanding service with a blue chip customer base that enhances our existing unified communications services business," said Call Sciences President and CEO Mike McCoy. "The addition of more than 700,000 users will enhance our ability to continue our market leading position in unified communications."

About Call Sciences
Founded in 1993, Call Sciences is an international corporation that develops and markets unified communications solutions, making it easy for service providers and corporate enterprises to deliver enhanced personal communications services. As a leader in the unified communications market, Call Sciences remains true to the unique idea that advances in communications technology should make life easier. With its headquarters in Edison, N.J., Call Sciences is a privately held company and maintains offices in Glencoe, Illinois; and Slough, the United Kingdom. For more information, visit the company's Web site, www.callsciences.com , or call 800-669-5400.

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 carriers and enterprises 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, 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^TM 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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