Avici Demonstrates Carrier Class System Scalability and Reliability of its Routing Platform.

N. BILLERICA, Mass. -- Isocore Evaluates Avici Capabilities Against Next-Generation Carrier Requirements for Core Routers

Avici Systems today announced that Isocore Internetworking Lab, as part of its ongoing testing program for Avici has completed a set of tests of Avici's carrier-class system scalability, reliability, and operational performance. Isocore Internetworking Lab, a leading independent technology validation entity, conducted a series of tests using Avici's unique capabilities fundamental for carriers seeking to converge high margin services over a next-generation IP/MPLS core network.

"Avici continues to be the only proven solution tested by Isocore to offer carrier class reliability, high performance and multi-chassis scalability", said Avici CEO Steve Kaufman, "Our ongoing work with Isocore shows our commitment to rigorous testing to exceed the requirements of our carrier customers."

The testing conducted by Isocore was designed to encompass the operational conditions existing in real-world carrier networks today and expected in future years. By using large network topologies, forwarding high packet volumes and enabling multiple protocols simultaneously, Avici routers demonstrated the key attributes required to achieve carrier-class 99.999% availability.

Highlights of the testing included:

1. Multi-chassis System Scalability - Avici's routing platforms scaled seamlessly, demonstrating in-service scaling from a single chassis to a four-chassis system, without affecting the operational functionality and forwarding. Each of the four interconnected Avici TSR chassis is designed to support up to 40 10 Gigabit linecards, for a total system capacity of 1.6 Terabits.

2. High Reliability- Avici's NSR(TM) non-stop routing technology successfully enabled in-service software upgrades and provided complete protection against a comprehensive set of hardware and software failure conditions.

3. Link Scalability- Isocore successfully tested Avici's ability to scale links from 2.5 Gbps to 60 Gbps (Full Duplex Operation), using Avici's Composite Link(TM) technology.

About Avici Systems

Avici Systems Inc., headquartered in North Billerica, Mass., is a leading provider of purpose-built carrier-class routing solutions for the Internet. Avici's family of routers is designed to meet carrier requirements for the highest scalability, reliability and network availability, while lowering the total cost of building and operating their networks. The company's routing systems provide new IP solutions to some of the world's leading service providers. For more information, please visit us at www.avici.com.

Avici, TSR, SSR, QSR, IPriori, Velociti, NSR, MSC, ASAP, and RAPID are trademarks of Avici Systems Inc.

This release contains information about Avici's future expectations, plans, and prospects that constitute forward-looking statements for purposes of the safe harbor provisions under the Private Securities Litigation Reform Act of 1995. Such forward-looking statements are subject to risks and uncertainties, which could cause actual results to differ materially from those anticipated. When used in this press release, the word "will", "expected" and other similar expressions are intended to identify such forward looking statements. Such risks and uncertainties include, but are not limited to, market acceptance of Avici products, services and enhancements, customer purchasing patterns and commitments, development of the market place, product development and enhancement, intensity of competition of other vendors, technological changes and other risks set forth in Avici's filings with the Securities and Exchange Commission.