ALLTEL Awards Three-year Exclusive Contract to CIENA; CIENA's MultiWave Sentry Enables Network Scalability and Protocol Flexibility.

LINTHICUM, Md.--(BUSINESS WIRE)--July 7, 1999--

CIENA Corporation (Nasdaq:CIEN) today announced that ALLTEL has selected and deployed its dense wavelength division multiplexing (DWDM) optical transport equipment along a 2,500 mile fiber optic route in ALLTEL's multi-state network.

In addition, CIENA has been awarded a three-year exclusive contract with ALLTEL for optical network business in the network.

ALLTEL's total fiber optic cable network is expected to exceed 12,000 miles by the end of 1999, giving ALLTEL a presence in most major cities in the Southeast United States, along the Eastern Seaboard and in the Great Lakes Region. The facilities-based network will stretch across 12 states and the District of Columbia. ALLTEL's communications operations include local telephone, wireless, long-distance, Internet and paging services.

"DWDM technology gives us the ability to expand our fiber network rapidly to meet the growing demands of our customers," said Mike Flynn, group president for ALLTEL's communications operations. "DWDM, coupled with the recent deployment of Asynchronous Transfer Mode (ATM) switches, will allow us to simplify the network, reduce network costs and continue to offer new services."

ALLTEL deployed ATM switches throughout its network in 1998. The company will use CIENA's MultiWave Sentry(TM) to carry traffic along three routes, from Raleigh to Charlotte in North Carolina, Philadelphia to Pittsburgh in Pennsylvania, and Jasper to Live Oak in Florida.

"Alltel is clearly in touch with the bandwidth demands that its customers are facing at the moment as well as the potential constraints that networks will face even one year from now," said Patrick Nettles, chief executive officer and president at CIENA Corporation. "New trends in running pure data networks over DWDM exploit the best features of CIENA's MultiWave products."

ABOUT CIENA

CIENA Corporation's market leading optical networking systems form the core of telecommunications networks worldwide. CIENA's LightWorks(TM) architecture changes the fundamental economics of service provider networks by simplifying the network architecture and reducing the cost to operate it. CIENA's networking solutions utilize bandwidth expanding dense wavelength division multiplexing (DWDM) technology and include the MultiWave(R) family of products for long-haul, short-haul, metropolitan and access applications. CIENA's CoreDirector(TM), an intelligent optical core switch, delivers dynamic provisioning, grooming, flexible capacity management and survivability. CIENA's most recent addition to its family of products is the AXR 500, a next generation multi-service transport platform that enables public network operators to efficiently transport existing voice and digital private line services along with new high bandwidth frame-based data services over a single integrated fiber optic access and interoffice network. Through its CIENA Services subsidiary, 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 and its LightWorks architecture can be found on its worldwide Website: http://www.ciena.com.

ABOUT ALLTEL

ALLTEL provides wireline and wireless communications services to more than 7 million customers in 24 states and has information services clients in more than 50 countries and territories.

ALLTEL is a customer-focused, information technology company that provides wireline and wireless communications and information services. -- ALLTEL, NYSE: AT -- www.alltel.com

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 in such forward-looking statements, due to risks and uncertainties associated with the Company's business, which include difficulty in anticipating core demand for bandwidth as well as other risk factors disclosed in the Company's Annual Report on Form 10-K, as filed with the Securities and Exchange Commission on December 9, 1998, as updated and restated into "plain English" format in a Form 8K filed April 5, 1999, and as further updated by the Company's Quarterly Report on Form 10-Q as filed with the Commission on May 21, 1999.