CIENA and Juniper Networks Demonstrate Interoperability.

LINTHICUM, Md./MOUNTAIN VIEW, Calif.--(BUSINESS WIRE)-- Feb. 23, 1999--

Next Generation Network Architecture Exhibited

at OFC, Booth No. 901

CIENA Corporation (Nasdaq: CIEN) and Juniper Networks, provider of the industry-leading M40 Internet backbone router, today announced successful interoperability testing between Juniper Networks' M40 router and CIENA's MultiWave Sentry(tm) dense wavelength division multiplexing (DWDM) optical networking system.

The announcement demonstrates the direct connectivity of Juniper Networks' and CIENA's equipment and showcases the availability of an integrated Internet Protocol (IP)-to-DWDM solution that dramatically simplifies IP packet transmission via a MultiWave(R) optical core.

"Competitive carriers and Internet Service Providers (ISPs) searching for better alternatives to legacy network architectures will find the results of our interoperability testing with Juniper compelling," said Steve Chaddick, CIENA's senior vice president, strategy and corporate development. "The capacity, reliability and flexibility of a network built with Juniper's M40 routers on a CIENA MultiWave optical core offers significant bandwidth and service flexibility."

Testing between CIENA and Juniper Networks utilized cross- continent IP to DWDM network topologies. The evaluation also demonstrated the M40's ability to meet the stringent jitter measurements required by the Bellcore GR 253 standard by successfully passing jitter-free packets continuously using the MultiWave Sentry system.

"The phenomenal growth of Internet traffperability testing between Juniper Networks and simplify and cost-reduce their networks while mabsolutely error free through 12,000 Km of fibeon systems to handle the link, thus proving thagrowth and provide simple IP-over-glass connectivity," said Joe Furgerson, vice president of marketing for Juniper Networks. "We designed the M40 Router to provide both finteroperable with a leading optical networking uting system designed specifically to meet the Fiber Communications (OFC) Conference in San Diecommunications networks worldwide. CIENA's netwagement software, the MultiWave Optical Add/Droiary, CIENA provides a range of engineering, furnishing and installation (EF&I) services for telecommunications service providers in the areas of transport, switching and wireless communications.

Additional information about CIENA can be found on its World Wide Website: http://www.ciena.com.

ABOUT Juniper Networks

Juniper Networks is the leading provider of the new generation of high-speed IP infrastructure platforms that meet the scalability, performance, density and compatibility requirements of rapidly evolving optically-enabled IP based networks. Using the breakthrough JUNOS software, ASICs, and wire-rate performance of the company's flagship M40 router, Juniper Networks enables new IP, content and broadband access service providers to maintain a competitive advantage by growing their businesses rapidly through new IP service delivery. The M40 is deployed in the world's largest and fastest Internet networks.

The M40 router is supported by Juniper Networks world-class service, support and manufacturing teams and Internet experts. The company is headquartered in Mountain View, California. For more information on Juniper Networks, please contact the company at 650/526-8000 or visit their Web site at http://www.juniper.net.

NOTE TO INVESTORS:

Forward-looking statements in this release, 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, and 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 Annual Report on Form 10-K, as filed with the Securities and Exchange Commission on February 18, 1999.