Business Editors/High-Tech Writers

CUPERTINO, Calif.--(BUSINESS WIRE)--Aug. 21, 2001

Portal Software, Inc. (Nasdaq:PRSF) today announced that Infranet(R), Portal's real-time, convergent software platform, has been selected by Airtel-Vodafone, a leading provider of wireless communications in Spain. The Infranet platform will enable Airtel-Vodafone to rate GPRS and value-added wireless services.

Faced with the challenge of offering next-generation services and supporting rapidly changing business models, Airtel-Vodafone recognized the tremendous flexibility of Infranet. Airtel-Vodafone selected the scalable, off-the-shelf Infranet platform because of its capability of supporting transactional real-time GPRS as well as next generation services. "Portal is delighted to be working with Airtel-Vodafone, further extending the company's involvement with the Vodafone Group," commented Ian Perry, vice president, Portal Software EMEA.

About Airtel

Airtel-Vodafone is the second mobile wireless operator in Spain, belonging to Vodafone Group, world leader in mobile wireless with more than 83 million customers in 30 countries.

About Portal Software, Inc.

Portal Software develops customer management and billing software for communications and content service providers. Portal's real-time, convergent platform enables its customers to rapidly create, deploy, and bill for services with flexible business models. Portal's software is licensed by a majority of the world's largest communications providers to deliver voice, data, video, and content services across wireless, wireline, cable, and satellite networks. Customers include Vodafone, AOL Time Warner, Deutsche Telekom, NTT, WorldCom, China Telecom, Reuters, Telstra, Sprint, China Mobile, Telenor Mobil, and France Telecom.

Note to Editors: Infranet is a U.S. registered trademark, and Portal and the Portal logo are trademarks of Portal Software, Inc. All statements made in this press release are made only as of the date set forth at the beginning of this release. Portal undertakes no obligation to update the information in the event facts or circumstances subsequently change.