

	NTT-ME Selects iBasis As First Internet Telephony Carrier iBasis to Carry International Voice and Fax Traffic For NTT-ME Customers Burlington, Mass.-March 13, 2000-iBasis, Inc., (Nasdaq: IBAS), a leading Internet-based communications service provider today announced that NTT-ME (Nippon Telephone and Telegraph-Multimedia and Engineering), a strategic subsidiary of NTT, Japan's largest international telecommunications carrier, has selected iBasis as its first Internet telephony service provider. Under the terms of the agreement, NTT-ME will be able to route international voice and fax traffic from its 29 million customers over iBasis' global IP network and provide termination services for iBasis traffic into Japan. This Internet telephony service agreement with iBasis enables NTT-ME to more efficiently route its international traffic and extend its global footprint. The agreement will significantly enhance iBasis' termination footprint in the major metropolitan centers of Japan and increase traffic over the iBasis Network. Initially, NTT-ME will exchange traffic with iBasis in the Tokyo metropolitan area and in other major cities in Japan. "NTT's selection of iBasis as its first Internet telephony carrier is further recognition of our unique ability to reliably provide toll quality service to tier one global carriers," said Ofer Gneezy, president and CEO of iBasis. "In NTT-ME, we have a partner that extends our global footprint into one of the largest communications markets in the world." "iBasis was an easy choice as our first partner for entering Internet telephony," said Kiyotaka Saito, senior manager, NTT-ME. "With their global reach and quality of service for VoIP, iBasis will enable us to more efficiently extend our global reach and expand our service." The Keys to Tier One Quality: The iBasis Network™ and Assured Quality Routing™ The iBasis Network™ is the world's largest international Cisco Powered Network™ (CPN™) for Internet telephony. Combining advanced technology with world-class IP and telephony engineering expertise, iBasis has built the world's first global network that guarantees toll quality voice and fax service. Toll quality is the telecommunications industry term for the highest level of service quality obtainable. The ability to deliver toll quality is a pre-requisite for carrying tier one carrier voice and fax traffic. The iBasis Network is optimized to deliver low latency and packet loss, high voice quality, no echo, high call completion and low post-dial delay-resulting in call quality equal to or better than that achievable over traditional PSTN lines. The key to maintaining the high level of quality required by the world's largest carriers is the company's proven, proprietary Assured Quality Routing (AQR) technology. About NTT-ME NTT-ME, (NTT Multimedia and Engineering), a strategic subsidiary of NTT, Japan's largest international carrier, employs world-class multimedia expertise to create a new generation of advanced IP, telecommunications and multimedia products and services. About iBasis Founded in 1996, iBasis (Nasdaq: IBAS) is the leader in advanced Internet-based communications. iBasis has built the world's first global IP network that delivers toll quality voice and fax service and other advanced hosted communications solutions, including VoCore, to global tier one carriers and other service providers. The iBasis Network™ is the world's largest international Cisco Powered Network™ for Internet Telephony. iBasis customers include 11 of the top 12 US international carriers. The company can be reached at its worldwide headquarters in Burlington, Mass., USA at 781-505-7500 or on the Internet at www.ibasis.net. iBasis has a long-standing strategic relationship with Cisco, as an Alliance Partner, an Ecosystem Partner, and one of only 21 Cisco Service Provider Global Accounts. Except for historical information, all of the expectations, projections and assumptions contained in the foregoing press release 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, the considerations described as "Risk Factors" in iBasis' prospectus dated March 8, 2000, and the company's other SEC filings. ### iBasis, The iBasis Network and Assured Quality Routing are registered trademarks of iBasis, Inc. Cisco and Cisco Powered Network are registered trademarks of Cisco Systems, Inc.