ONI Systems Selected By Dynegy/Telseon to Deploy All-Optical Networks in Metro Markets; ONI to Provide Telecommunications Equipment for 18 City Rollout.

Business Editors/High-Tech Writers

SAN JOSE, Calif.--(BUSINESS WIRE)--May 31, 2001

ONI Systems Corp. (Nasdaq:ONIS), a leading provider of optical telecommunications systems for the metropolitan and regional markets, today announced a multi-million dollar contract with Dynegy Global Communications, a subsidiary of Dynegy Inc. (NYSE:DYN), a Fortune 100 company providing energy and communications solutions. Dynegy and Telseon, a leading metropolitan optical networking provider, have entered into a network service agreement to develop an 18 city all-optical network capable of providing high-bandwidth solutions between multiple points-of-presence in select metropolitan markets.

The two companies will use ONI's ONLINE(TM) transport platform for 2001 deployments in Atlanta, Chicago, Dallas, Denver, Detroit, Los Angeles, Miami, New Jersey, New York, Orlando, Phoenix, San Diego, San Jose, San Francisco, Seattle, St. Louis, Tampa, and Washington D.C. Under a separate agreement with ONI, Telseon began deploying ONI equipment in their networks in Q1 2001.

"We are pleased that Dynegy and Telseon selected ONI Systems to expand into the metropolitan area markets," said Hugh Martin, president, chairman and chief executive officer, ONI Systems. "ONI continues to be the choice for carriers and service providers because our metro solutions are designed with the flexibility, service transparency and dynamic provisioning needed to yield considerable competitive advantages."

"The ONI ONLINE transport platform offers Dynegy a leading edge product in the metropolitan market for optical networking solutions," said Larry McLernon, chairman and chief executive officer, Dynegy Global Communications. "We can now offer high bandwidth services providing flexibility to match our customers needs at cost levels materially below comparable technology now available. This directly benefits our customers and allows Dynegy to link the metropolitan networks to our existing long-haul network, as well as third party networks, to provide an end-to-end, scaleable optical solution utilizing the latest generation of optical components."

"Telseon is driving technology standards in the metropolitan networking market and has a history of partnering with leading vendors to catapult innovation and deliver customer-centric solutions," said John Kane, chief executive office at Telseon. "ONI Systems ONLINE platform passed our rigorous qualification process testing more than 20+ criteria and offers the highest wavelength density per rack unit, enabling us to increase the utilization of our existing fiber assets while reducing total network cost of ownership."

The ONLINE transport platform is a highly manageable and flexible platform for delivery of high bandwidth optical services. The ONLINE platform maximizes the fiber capacity using DWDM technology, which is capable of simultaneously transporting up to 33 protected or 66 unprotected wavelengths per node and enable true optical service delivery by providing dynamic control of the optical layer. It is the only platform that supports both shared optical protection (O-BLSR) and dedicated optical protection (O-UPSR) with a failure recovery rate of 50 milliseconds or less. The ONLINE platform includes the ONWAVE(TM) family of products that efficiently groom lower speed services, such as Fibre Channel, Gigabit Ethernet (GbE) and OC-3/12/48, into a wavelength to increase wavelength efficiency and system capacity. The ONLINE platform leverages the OPTX operating system for wavelength and services management.

About Dynegy Inc.

Dynegy Inc. is a leading provider of energy and communications solutions to customers in North America, the United Kingdom and Continental Europe. Dynegy's newly established communications segment, Dynegy Global Communications (DGC), is engaged in pursuing and capturing opportunities in the converging energy and communications marketplace. DGC is focused on becoming a leader in the broadband marketing and trading arena by replicating Dynegy's wholesale energy convergence strategy through the implementation of a low-cost, global physical presence.

About Telseon

Telseon offers instantly scalable optical network services to enable companies to break the bandwidth bottleneck in the metropolitan area. With support from industry giants in key markets such as long-haul, storage and content services, Telseon is changing the way metropolitan bandwidth is acquired and delivered. Its customer and partner network serves more than 100 companies including 360networks, Epoch Internet, Everest Broadband, Incyte Genomics, Level 3, Riverstone and StorageLink.

The company is co-headquartered in Denver, Colorado and Mountain View, California and can be reached at 866-TELSEON or on the web at http://www.telseon.com. It has established operations in 20 U.S. metropolitan markets including Atlanta, Chicago, Cincinnati, Dallas, Denver, Detroit, Houston, Los Angeles, Miami, New York, Northern Virginia, Orlando, Philadelphia, Phoenix, San Diego, San Francisco Bay Area, Seattle, Silicon Valley, St. Louis and Tampa.

About ONI Systems

ONI Systems (Nasdaq:ONIS) develops, markets and sells optical networking equipment specifically designed to address bandwidth and service limitations of regional and metropolitan networks. Our products allow communication service providers to rapidly build high-capacity metro networks that are flexible, scalable and able to support multiple services on a single platform. Our products include the ONLINE11000, ONLINE9000, ONLINE7000, and ONLINE2500 transport platforms; the ONWAVE(TM) OC-48 SONET/SDH Add/Drop Multiplexer and the ONWAVE Data Multiplexer; and OC-192/STM-64 (10 gigabits per second) interface. The ONLINE(TM) transport platforms are complemented by our OPTX(TM) Software Suite for end-to-end wavelength and service management capabilities. The OPTX Software Suite includes the OPTX Network Designer, OPTX Management Portal, OPTX CORBA Gateway, OPTX Network Operating System (NOS) and more, as well as the OLMP(TM) optical link management protocol suite for standards-based internetworking. For additional information about ONI and its products, visit the company Web site at www.oni.com.

Note to Editors: ONI Systems, ONI, the ONI logo, ONLINE, OPTX, OLMP and ONWAVE are trademarks or registered trademarks of ONI Systems Corp. All other trademarks are the property of their respective owners.

This press release contains forward-looking information within the meaning of Section 21E of the Securities Exchange Act of 1934, and is subject to the safe harbor created by this section. Except for historical information, the matters discussed in this press release are forward-looking statements that are subject to risks and uncertainties that could cause actual results to differ materially from those projected. Such risks and uncertainties include, but are not limited to, our limited operating history which makes forecasting our future revenue and operating results difficult, our ability to develop and to achieve market acceptance of new products, our dependence on a small number of customers, our ability to add additional customers and our dependence on sole or limited source suppliers for several key components. These and other risks and uncertainties are described from time-to-time in ONI Systems' filings with the Securities and Exchange Commission, including ONI Systems' quarterly report on Form 10-Q for the quarter ended March 31, 2001, ONI Systems' annual report on Form 10-K for the year ended December 31, 2000 and other documents on file with the SEC.