CIENA Corporation Announces Deal with Japan Telecom.

LINTHICUM, Md.--(BUSINESS WIRE)--Sept. 17, 1997--CIENA Corp. (NASDAQ:CIEN) announced today that its MultiWave Sentry(TM) dense wavelength division multiplexing (DWDM) system has been selected by Japan Telecom Co. Ltd. for deployment along several portions of its national fiber optic network.

The installation of CIENA's MultiWave Sentry(TM) system will enable Japan Telecom to immediately expand Japan's busiest telecommunications route, the Tokyo-Osaka-Hiroshima corridor, by a factor of four without requiring the costly installation of new optical fibers or SDH regenerators. The system will operate with CIENA's WaveWatcher(TM) network management system, and will be scaleable up to 16 channels, providing Japan Telecom with the flexibility to further increase capacity as demand requires. Deployment of Sentry is expected to begin in early 1998.

"The CIENA WDM system will provide an immediate increase in our network capacity, allowing us to continue our aggressive addition of new services such as frame relay, Internet and mobile communications," said Yoshihisa Osada, managing director of Japan Telecom.

"Japan Telecom's selection of MultiWave Sentry represents an important step toward CIENA's goal of a broader customer base and an enhanced international presence," said Patrick Nettles, CIENA's president and chief executive officer. "We are excited about beginning a relationship with Japan Telecom and look forward to helping them achieve their goal of providing customers with flexible, reliable and cost-competitive services."

Japan Telecom is one of the most successful and aggressive of the new common carriers (NCCs), which have been approved by the Japanese government to compete against Japan's predominant terrestrial carrier, NTT. Founded and controlled by Japan's National Railway (JNR), Japan Telecom has installed its fiber optics base along the railway's right of way. Publicly held since 1996, they recently received regulatory approval to merge with ITJ, Japan's second largest international carrier.

Nissho Electronics Corp. continues to act as CIENA's exclusive distributor in Japan. "Nissho is very pleased to announce this contract with Japan Telecom for the supply of CIENA's DWDM systems," said Norio Saitoh, executive vice president at Nissho Electronics Corp. "This is yet another example of the acceptance of CIENA's technology as the standard for DWDM in Japan."

Nissho also supplies equipment to CIENA's other Japanese customer, Teleway Japan. Nissho's role has expanded in recent months to provide the logistics required for turnkey installation, as well as 24 hour technical support. -0-

ABOUT CIENA: CIENA Corp. is a worldwide market leader of open architecture, dense wavelength division multiplexing (DWDM) systems for long-distance and local exchange carriers. CIENA'S DWDM solutions include the MultiWave(TM) 1600 long-haul transport system, WaveWatcher(R) network management software, the MultiWave Optical Add/Drop Multiplexer, the MultiWave Sentry(TM) enhanced long-distance transport system and the new MultiWave Firefly(TM) and MultiWave Metro(TM) short-haul systems. An optical fiber without DWDM technology carries a single color of laser light, or a single wavelength, on which travels approximately 32,000 voice or data transmissions. DWDM technology divides the single color into multiple colors or channels, thereby multiplying the capacity of the fiber by the number of channels. This enables service providers to expand bandwidth without the expensive process of adding more fibers. With CIENA's new MultiWave Firefly, existing capacity of a fiber will increase by 24 times, which equates to 768,000 voice or data transmissions.

NOTE TO INVESTORS: Forward-looking statements in this news release, including statements regarding the timing of expected MultiWave Sentry installations at Japan Telecom, 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 by such forward-looking statements, due to risks and uncertainties associated with new product development in the DWDM field, the Company's dependence on its major customers and their spending patterns, the recent introduction of its products, and the overall management of the Company's expansion. The forward-looking statements should be considered in the context of these and other risk factors disclosed in the Company's report on Form 8-K, as filed with the Securities and Exchange Commission (SEC) on Feb. 19, 1997, and as further amended and restated by Amendment No. 1 to the Form 8-K, as filed with the SEC on Aug. 6, 1997, and as supplemented by the discussion of risk considerations in the Company's Quarterly Report on Form 10-Q as filed with the SEC on Aug. 20, 1997.

CONTACT: CIENA Corp.

Denny Bilter, 410/865-8500

or

Hill & Knowlton

Glenn Jasper, 212/885-0486

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Investor: CIENA Corp.

Suzanne DuLong, 410/865-8500