TELIA AB OF SWEDEN DEPLOYS CIENA's DWDM EQUIPMENT

Linthicum, MD — 06/09/1998

Ciena Corporation (Nasdaq: CIEN) today announced that Telia AB of Sweden has deployed the MultiWave Sentry™ 1600 dense wavelength division multiplexing (DWDM) system in its backbone network. While actual installation in Telia's network began in late 1997, the MultiWave Sentry has completed evaluation and now is carrying live traffic.

"We are pleased to add Telia to our growing list of customers in Europe," said Gary Smith, Ciena's vice president of international sales. "This deployment is further evidence of the increasing demand for bandwidth worldwide as data services continue to grow."

"Telia's decision to deploy the MultiWave Sentry 1600 will give them the transport platform required to build a next-generation data-centric network," continued Smith. "Ciena's open architecture and DirectConnect feature enable Telia to natively access ATM switches and IP routers at the optical layer, thereby eliminating the need for SONET/SDH multiplexers in data-centric applications."

Telia represents the third European customer won by Ciena in the last year since entering this market. Ciena's new European support center located near London's Heathrow International Airport will provide technical and post sales support for Telia.


About Ciena

Ciena specializes in network transition. We provide the flexible platforms, intelligent software and professional services to build converged networks for enhanced services and applications. With a growing global presence, Ciena leverages its heritage of practical innovation to deliver maximum performance and economic value in communications networks worldwide. For more information, visit www.ciena.com.
ABOUT TELIA

Telia competes in one of the world´s most competitive telecommunications markets which places huge demands on service levels, technological excellence and flexibility. Telia is currently developing new markets and services while expanding its geographic base outside Sweden´s borders.

Telia is the leading supplier of telecom-based information services in the Nordic/Baltic region. At the same time, "seamless" pan-European and global services are being provided through powerful alliances and partnerships in Europe and around the world. Annual turnover in 1997 reached 46,444 MSEK and the number of employees amounted to approx. 34,000.

Note to Investors
Forward-looking statements in this release, including statements regarding the increasing demand for bandwidth worldwide, 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 the Company's dependence on its major customers and their spending patterns, including specifically the impact on the Company's near term operating results of WorldCom's recently announced change in purchasing practices, the challenge of transitioning to the manufacture of multiple product lines in fiscal 1998, and the overall management of its expansion. The risks associated with the recently announced merger with Tellabs may also affect actual results. The forward-looking statements should be considered in the context of these and other risk factors disclosed in the Company's Form 10-Q, filed with the Securities and Exchange Commission on May 21, 1998.
Press Contacts:
Nicole Anderson
Ciena Corporation
(877) 857 -7377
pr@ciena.com
Investor Contacts:
Marie Downing
Ciena Corporation
(888) 243-6223
ir@ciena.com