PSINET NAMES CIENA STRATEGIC SUPPLIER OF INTELLIGENT OPTICAL NETWORKING SOLUTIONS FOR GLOBAL NETWORK EXPANSION

ISP Using CIENA's Long- and Short-Haul Systems For Network Upgrades

Linthicum, MD — 04/05/2000

Ciena Corporation (CIEN) today announced that PSINet (Nasdaq: PSIX), the Internet Super Carrier, has named Ciena a strategic supplier of intelligent optical networking solutions for expanding PSINet's global IP-optimized backbone network. PSINet and Ciena have signed a three-year supply agreement for Ciena's MultiWave CoreStream™ and MultiWave Metro™ intelligent optical transport systems.

Supporting PSINet's network upgrades announced last year, Ciena will supply the long-haul and short-haul systems for expanding backbone network capacity in Europe and North America for continued IP traffic growth.

"PSINet will use Ciena's technology to scale our backbone network up to two terabits per second over each fiber pair, enabling us to provide sufficient capacity for our customers' bandwidth-intensive applications," said Mark Fedor, vice president of engineering at PSINet. "The density of Ciena's products create significant cost savings on power and space in our points of presence, and their customer support services around the world are very nimble. Their ability to immediately deliver and support a carrier-class solution that meets growing capacity needs down the road were key criteria in our decision to name Ciena a strategic supplier of optical solutions."

"PSINet is recognized worldwide as a forerunner in the Internet data communications market - a carrier that has focused on building its network for the next generation of business applications," said Patrick Nettles, Ciena's president and chief executive officer. "We are pleased that PSINet has identified Ciena's optical networking solutions as a key element in the future of data networking and as a critical part of its network expansion."

Ciena's MultiWave CoreStream is the industry's first optical transport platform scalable to a capacity of approximately two terabits per second over a single fiber pair. MultiWave Metro is the industry's leading intelligent optical transport system for metropolitan area networks. MultiWave Metro's ability to support a variety of survivable network topologies simultaneously will provide PSINet ring, mesh and point-to-point logical connectivity for transporting IP traffic. In addition, MultiWave Metro's scalable architecture allows more easily managed network growth in frequently unpredictable metropolitan networks.

Ciena's optical transport solutions are a key element of Ciena LightWorks™, a comprehensive blueprint for building intelligent optical networks. With this next-generation architecture, Ciena enables carriers around the world to rapidly transition to dramatically simpler yet higher capacity networks while achieving greatly reduced equipment and operating costs. Ciena's recently unveiled LightWorks Toolkit™ provides a suite of silicon-, optics- and software-based technologies to help carriers build and deliver differentiating dynamic optical services.


About Ciena

Ciena Corporation's market-leading optical networking systems form the core for the new era of networks and services worldwide. Ciena's LightWorks™ architecture enables next-generation optical services and changes the fundamental economics of service-provider networks by simplifying the network and reducing the cost to operate it. Additional information about Ciena can be found at http://www.ciena.com.
About PSINet
Headquartered in Herndon, Va., PSINet is an Internet Super Carrier offering global eCommerce infrastructure and a full suite of retail and wholesale Internet services through wholly-owned PSINet subsidiaries. Services are provided on PSINet owned and operated fiber, satellite, Web hosting and switching facilities providing direct access in more than 800 metropolitan areas in 28 countries on five continents. PSINet information can be obtained by e-mail at info@psi.com, by accessing the Web site at www.psi.com or calling in the U.S., 800-799-0676.
Note to Investors
Forward-looking statements in this release, including, but not limited to, PSINet's estimated need for long- and short-haul systems over the next three years, and the cost savings, deployment timing, scalability and network management benefits of Ciena's (the Company's) products, are based on information available to the Company as of the date hereof. The Company's actual results could differ materially from those stated or implied in such forward-looking statements, due to risks and uncertainties associated with the Company's business, which include the risk factors disclosed in the Company's Report on Form 10-Q filed with the Securities and Exchange Commission on February 17, 2000.
Press Contacts:
Nicole Anderson
Ciena Corporation
(877) 857 -7377
pr@ciena.com
Investor Contacts:
Marie Downing
Ciena Corporation
(888) 243-6223
ir@ciena.com