Clarent Corp. Triples Carrier Gateway Port Density; New Clarent Carrier Gateway 1200 Increases Port Density From 4 T1/E1s to 12 T1/E1s in the Same Footprint.

Business Editors &High-Tech Writers

REDWOOD CITY, Calif.--(BUSINESS WIRE)--Jan. 24, 2000

Clarent(TM) Corp. (Nasdaq:CLRN), a worldwide leader in providing carrier-grade, phone-to-phone Internet Protocol (IP) telephony solutions, announced today a new higher density gateway.

The Clarent Carrier Gateway 1200 is a high capacity Internet telephony gateway for connecting telephone voice calls, fax calls and modem data calls over the Internet or a TCP/IP Intranet. The new gateway interacts with the billing, call routing and network administration in the Clarent Command Center(TM) software package.

Scheduled for availability in February, the higher density gateway will support 8, 10 or 12 spans (24 ports per T1 span/30 ports per E1 span) in a single 5U chassis, allowing each new gateway to control up to 360 simultaneous calls all in the same 5U chassis. Large networks built using the new Clarent Carrier Gateway 1200 will be able to scale rapidly with one-third the footprint previously required.

The Clarent Gateway 1200 is the latest in the family of Clarent ONE (Open Network Environment) products, which also include the Clarent Gatekeeper and Clarent ClearView network management suite.

Clarent ONE, a product and technology architecture which was announced in September 1999, is intended to provide a standards-based, multiprotocol service management and delivery platform for large-scale carrier VoIP networks and to serve as the basis for the development and deployment of advanced communications applications, solutions and services.

&uot;Clarent plans to offer our customers a variety of port density alternatives,&uot; said Mike Vargo, chief technology officer, Clarent Corp. &uot;Our goal is to provide state of the art IP telephony products that support new or incumbent carriers, with differing levels of call volumes, terminating different access pipes. Our family of gateways will continue to be administered and driven by the intelligent back-end that is the Clarent Command Center.&uot;

More About the Clarent Carrier Gateway 1200

Clarent uses a combination of DSP and host-based voice processing for toll-quality voice transmission and also uses patent-pending Clarent ThroughPacket technology to reduce the chances of packets being dropped or lost in the network and to increase the efficiency of routers.

All ports on Clarent Carrier Gateway 1200s are &uot;universal&uot; -- they can simultaneously handle voice, real-time fax and data traffic, transparently giving service providers maximum flexibility. The Clarent Gateway 1200 is standards-based, supporting G.711, G.723.1 and G.729a codes as well as Q.931 signaling. Gateway signaling includes support for SS7/C7, PRI-ISDN, T1, E1 and PBX connections.

The gateway uses industry-standard G.165 echo cancellation. A single span T1 or E1 Clarent Carrier Gateway 1200 can grow to 10 or 12 spans within the same housing to achieve the desired density at a given point of presence. Up to 360 ports can be active simultaneously in one gateway. Clarent's Service Editor, an IVR toolbox, allows comprehensive customization of the voice interface.

There is optional PSTN fall back if the IP network is unavailable. Redundant power supplies provide a high level of reliability.

Forward Looking Statements

This release may contain forward-looking statements regarding Clarent'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 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 Nov. 23, 1999.

About Clarent Corp.

Clarent Corp. 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 and has offices in major cities in Asia, Europe, Latin America and North America. Additional information about Clarent is available at www.clarent.com.

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

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