Avici Systems Demonstrates Interoperability with Leading Optical Networking Vendors at OFC 2003; Validates IP-Optical Interworking Open Standards.

Business Editors/High-Tech Writers

OFC 2003

N. BILLERICA, Mass.--(BUSINESS WIRE)--March 25, 2003

Avici Systems, Inc. (NASDAQ: AVCI), the specialist in high reliability routing solutions for the Internet, today announced successful multi-vendor interoperability using the Optical Internetworking Forum's (OIF) User-to-Network Interface (UNI) specification. Avici will be participating in a live demonstration at the Optical Fiber Communications (OFC) Conference in Atlanta from March 25 - 27, 2003 in Booth # 7620. This demonstration will highlight dynamic, IP connection establishment between network client devices, such as IP routers, and optical network switches. The integrated UNI/NNI (Network to Network) solution enables service providers to signal and route traffic dynamically across a multi-domain, multi-node optical core network. Avici is committed to supporting open standards such as UNI to enable intelligent optical control plane solutions for carriers.

Avici routers successfully demonstrated UNI signaling interoperability with 12 optical networking vendors including optical cross connects, metro and long haul optical transport equipment, add/drop multiplexers, protocol test equipment and network software providers. Standards-based initiatives, such as the OIF's UNI signaling, simplify operational procedures, provide significant cost reductions, and accelerate the introduction of new differentiated services for service providers.

"The participants in the OIF's Interoperability Demonstration at OFC 2003 are genuinely committed to interoperable solutions," said Joe Berthold, CIENA Corporation, president of the OIF. "Each company in the demo has passed a rigorous pre-event test based on real-world conditions. The demonstration will highlight equipment and solutions that will meet the interoperability demands of the optical networking industry in the near-future."

"Avici and Sycamore worked closely together to demonstrate interoperability between Sycamore's Intelligent Optical Switches and Avici's carrier-class routing products using the UNI specification, " said Kevin Oye, Vice President of Systems and Technology at Sycamore. "Both companies share a common commitment to open standards and interoperability to help service providers reduce costs, improve operations, and accelerate the introduction of new services."

"Network operators consider interoperability between the IP and transmission networks critical to reducing costs, improving reliability and better integrating IP and transmission networks," said Chris Gunner, Sr. Vice President of Research and Development at Avici. "Successfully demonstrating interoperability with leading optical vendors is a strong statement of Avici's commitment to support service provider initiatives to reduce capital and operational costs, streamline operations, and drive profitable services."

OIF's NNI/UNI Interoperability Demo

The Optical Internetworking Forum (OIF) will sponsor the broadest demonstration of optical networking capabilities at OFC 2003 in booth #7620, Hall B. The event will be the first-ever demonstration of the OIF's integrated UNI/NNI solution. The goal of the event is to achieve dynamic, end-to-end connection establishment between client devices and optical network elements in the Control Plane. OIF is a rapidly growing non-profit organization with 250+ member companies to date, including many of the world's leading carriers, component and system vendors. The purpose of the OIF is to accelerate the deployment of interoperable, cost effective, and robust optical internetworks and their associated technologies. More information on the OIF and the interoperability demo can be found at www.oiforum.com.

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's TSR, SSR, QSR, NSR, and IPriori 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 words "will be" 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.