ITXC Adds Clarent Products to Its Internet Telephony Network ITXC.net.

REDWOOD CITY, Calif. and PRINCETON, N.J.--(BUSINESS WIRE)--Dec. 16, 1999--

Clarent(TM) Corporation (Nasdaq:CLRN), a worldwide leader in providing carrier-grade, phone-to-phone Internet Protocol (IP) telephony solutions and ITXC Corp(R) (Nasdaq:ITXC), the tier one carrier of Internet telephony, announced today that ITXC has added a range of Clarent products to ITXC.net, ITXC's global Internet telephony network. These products include Clarent gateways, the Clarent Command Center and Clarent Gatekeeper.

ITXC is rolling out its initial support of Clarent equipment in Malaysia with Circle Communications, a pan-Asian carrier (Circle Com) and with PT Satelit Palapa of Indonesia (Satelindo). Satelindo is currently originating calls that will be routed over the ITXC infrastructure network. Circle Com's plans are to offer the service in Japan, Indonesia, Hong Kong, the USA, the Philippines, Australia and the UK by late January 2000. "Clarent and ITXC seem to be a good fit in our global expansion plans," said Michael Chan, deputy chief executive officer of Circle Communications. "With ITXC's vast global network, we expect that Circle Com will be able to penetrate the market at a rapid pace with minimum investments in our global network infrastructure."

"Clarent has achieved significant penetration of both the carrier and the Internet telephony service provider market," said Tom Evslin, ITXC chairman and CEO. "A number of these service provider organizations are interested in becoming affiliates of ITXC. We believe that these new affiliates should be able to get the immediate advantage of ITXC traffic and network size and ITXC.net should be able to grow even faster now that we support those who have chosen or are choosing Clarent equipment. We also believe that Clarent's international base of carrier customers will benefit both from the size of the ITXC network and from the unique BestValue(TM) routing technology developed by ITXC which delivers telephony quality of service with Internet transport economics."

"We believe that ITXC is a strong operator of a rapidly growing Internet telephony network. Clarent's international base of carrier customers will be able to benefit by having ITXC as a potential partner to share traffic. We are very happy to be working with ITXC," said Jerry Chang, CEO and president of Clarent Corporation. "Clarent's gateways provide the SS7 and C7 signaling support that we believe the major carriers need in order to take full advantage of ITXC.net. The Clarent Command Center and Clarent Gatekeeper currently provide ITXC with a common platform for administration, call routing and back end management for iNOW! interoperable Cisco and Clarent gateways."

Forward Looking Statements

This release may contain forward-looking statements regarding Clarent's and/or ITXC's products, business, customers or other factors that may affect future earnings or financial results. Such statements involve risks and uncertainties, including but not limited to potential issues relating to interoperability, inability to introduce new products, ability to retain key customers, changes in market conditions, government regulations, the international communications industry, technological changes and other factors, which could cause actual results to vary materially from those expressed in or indicated by the forward-looking statements. These risks and uncertainties are described further in the risk factors discussed in Clarent's recent Prospectus, filed with the Securities and Exchange Commission on November 23, 1999 and in the ITXC quarterly report filed on October 28, 1999.

About Clarent Corporation

Clarent Corporation is a premier provider of scalable, IP telephony products to carriers and Internet service providers around the world. Clarent's intelligent architecture and the Clarent Command Center enable Clarent products to route, manage, inter-connect and terminate high volumes of calls for service provider customers including the world's largest long distance telecommunication companies. According to an iLocus report published in 1999, more minutes travel across Clarent-enabled networks worldwide than those of any other equipment supplier.(a)

Founded in July 1996, Clarent is headquartered in Redwood City, California and has offices in major cities in Asia, Europe, Latin America and North America. Additional information about Clarent is available at www.clarent.com.

About ITXC

ITXC Corp is the tier one carrier of Internet telephony. ITXC.net is the infrastructure for voice on the Internet with over 145 IP PoPs in 91 cities and 42 countries. Network affiliates include international carriers, ISPs and newly formed Internet telephony service providers (ITSPs.) Key Affiliates include Ameritech, Bell Atlantic, China Telecom, GTS and Korea Telecom, among others.

ITXC sells international call completion and enhanced telephony services including international toll free calling to carriers, PTTs and resellers. These services are routed over ITXC.net using the public Internet and ITXC's patent pending BestValue Routing technologies to assure quality. For more information, please visit www.itxc.com

(a) "IP Telephony Clearinghouses -- A New Business Model." Published November 1999 by iLocus. iLocus, a division of Cape Saffron Ltd., is a UK-based research group focused on the IP telephony industry. http://www.ilocus.com

Note to Editors: Clarent is a registered trademark of Clarent Corporation in the United States and other jurisdictions. ITXC, ITXC.net and BestValue Routing are registered trademarks of ITXC Corp. All other company or product names mentioned may be trademarks or registered trademarks of the respective companies with which they are associated.