iBasis and Openwave Form Strategic Relationship;
iBasis To Become Openwave Global ASP Partner For Unified Messaging

Openwave's Advanced Wireless Capabilities To Extend iBasis VoCore Enhanced Services Solution

BURLINGTON, MA and REDWOOD CITY, CA - January 30, 2001 - iBasis, Inc., (Nasdaq: IBAS), the leader in advanced voice-based Internet communications, and Openwave Systems Inc., (Nasdaq: OPWV), the worldwide leader of open IP-based communications infrastructure software and applications, today announced a relationship that will enable iBasis to become an Openwave global ASP (Application Service Provider) partner offering enhanced communications services to wireless carriers and other service providers. The companies plan to engage in joint sales and marketing to promote iBasis' VoCore solution extended with Openwave unified messaging capabilities optimized for wireless carriers and other communications service providers. These new iBasis VoCore services will be based on Openwave's unified messaging offering and will provide a comprehensive package of hosted communications services, including email, voicemail, faxmail, mobile phone synchronization, and personal contact management.

"Wireless carriers like our customer China Mobile, China's largest mobile carrier and the world's largest single operator network, understand the need to seek partners like iBasis, who offer high service quality, speed to market, a range of enhanced services, and a global footprint that complements, rather than competes with, their own domestic mobile communications business," said Ofer Gneezy, president and CEO of iBasis. "This broader strategic relationship with Openwave will enable us to offer a compelling array of proven wireless services to the world's booming mobile communications markets. In addition, this integrated solution helps to bring our unified messaging services into strategic alignment with our planned roll-out of speech-enabled business services, which we believe will have an especially strong appeal for mobile users."

"In selecting iBasis as a global ASP partner for our unified messaging offering, we required a partner with proven service credentials," said Don Listwin, president and CEO of Openwave. "We found in iBasis a partner whose service is tested around the clock by many of the world's largest carriers and whose strategic focus on advanced communications solutions matches our own. We look forward to offering iBasis' ASP solution to our customers."

Industry analyst firm, Ovum Group, predicts that the total revenues from unified messaging services will increase from $1.2 billion in 2001 to $31 billion in 2006.

Extending VoCore With Openwave Unified Messaging

iBasis VoCore enhanced services platform offers a hosted solution for carriers who want to quickly provide compelling, new communications services that can increase customer loyalty and improve margins. iBasis VoCore's carrier-class unified messaging offerings leverage:

· Openwave's unified messaging offering, including email and directory services

· EMC's robust enterprise storage systems; and,

· Carrier-grade application servers from Sun Microsystems and Hewlett-Packard

iBasis expects that the extension of its VoCore solution with Openwave unified messaging will be cash neutral.

About Openwave
Openwave Systems Inc., (Nasdaq: OPWV), the combination of Phone.com and Software.com, is the worldwide leader of open Internet-based communication infrastructure software and applications. Openwave is a global company headquartered in Redwood City, California. For more information, please visit www.openwave.com .

About iBasis
Founded in 1996, iBasis (Nasdaq: IBAS) is the leader in advanced Internet-based communications. iBasis delivers toll quality voice and fax, as well as other advanced hosted communications solutions to service providers and enterprises. More than 100 international service providers, including 11 of the top 12 US-based international carriers and four of the five largest carriers in China, route traffic over the iBasis Network. iBasis customers include Worldcom, Cable & Wireless, NTT, Concert, China Unicom, China Mobile and Telstra. iBasis offers hosted, enhanced service solutions, including VoCore^SM and the IP CallCardTM pre- and post-paid calling card platform. In addition, the company is leveraging its global network and VoIP expertise to develop and deliver speech-driven web-based content, e-commerce and customer service applications. 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.net .

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 new 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' Preliminary Prospectus dated January 16, 2001, and the company's other SEC filings.

This release contains forward-looking statements relating to expectations, plans or prospects for Openwave Systems Inc. that are based upon the current expectations and beliefs of Openwave's management and are subject to certain risks and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. In particular, the following factors, among others, could cause actual results to differ materially from those described in the forward-looking statements: (a) risks associated with the development and licensing of software generally, including potential delays in software development and technical difficulties that may be encountered in the development or use of Openwave's software; (b) the ability to successfully partner with other companies; (c) competition and technological changes and developments; and (d) general risks of the Internet and wireless and wireline telecommunications sectors.

For a detailed discussion of these and other cautionary statements, please refer to the risk factors discussed in filings with the U.S. Securities and Exchange Commission ("SEC"), including but not limited to Phone.com's and Software.com's respective Quarterly Reports on Form 10-Q for the quarter ended September 30, 2000, Phone.com's and Software.com's most recently filed Annual Reports on Form 10-K, and Phone.com's registration statement on Form S-4 as filed on October 10, 2000. All documents also are available through the SEC's Electronic Data Gathering Analysis and Retrieval system (EDGAR) at www.sec.gov or from Openwave's Web site at www.openwave.com. The Company assumes no obligation to update the forward-looking statements included in this document.

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Assured Quality Routing and AQR are registered trademarks, VoCore is a service mark and iBasis, The iBasis Network, Internet Central Office and Internet Branch Office and IP CallCard are trademarks of iBasis, Inc. Cisco and Cisco Powered Network are registered trademarks of Cisco Systems, Inc. Openwave and the Openwave logo are trademarks of Openwave Systems Inc. All other trademarks are the property of their respective owners.