CIENA Multiservice Solutions Achieve Rural Utilities Service Acceptance.

Business Editors/High-Tech Writers

LINTHICUM, Md.--(BUSINESS WIRE)--May 18, 2004

Provides Access to Federal Funding for Purchase of ONLINE Edge, 7000 Series and Other Platforms from CIENA's Portfolio of Regional and

Access Network Solutions

CIENA(R) Corporation (NASDAQ:CIEN), a leading global provider of innovative network solutions, today announced that the Rural Utilities Service (RUS) of the U.S. Department of Agriculture (USDA) has granted RUS Acceptance to CIENA's ONLINE Edge(TM) multiservice platform and its DN 7000 series of multiservice edge switching solutions, which includes the DN 7000, DN 7050, DN 7100 and DN 7200 products.

RUS Acceptance for ONLINE Edge and the DN 7000 series augments previously announced RUS Acceptance for CIENA's ONLINE Metro(TM) and MetroDirector K2(TM) multiservice platforms, as well as its CN 1000 broadband loop carrier (BLC). Together, these platforms form a cost-effective, end-to-end solution for the delivery of advanced voice, video and data services on a converged broadband network.

With the approval of these products, CIENA offers a full suite of optical, data and access solutions that are available to independent operating companies (IOCs) for purchase using RUS program funding. RUS Acceptance indicates that these products meet strict requirements for field performance, compliance to standards, and US manufacturing.

"In addition to bringing broadband services and Internet access to rural areas of the country, RUS Acceptance for our service-delivery solutions also helps open new market opportunities for CIENA and our reseller partners," said Francois Locoh-Donou, CIENA's vice president of marketing. "With these RUS-approved solutions, CIENA is in an even stronger position to help rural network operators and utilities increase the profitability of their broadband offerings."

CIENA's DN 7000 series multiservice edge switching platform enables service providers to deliver customized services based on customer demand and service area density at lower price points than any product on the market today. On a single platform, the 7000 series delivers native Frame Relay, ATM, Ethernet, Circuit Emulation Services (CES), and Multiprotocol Label Switching (MPLS) functionality. The DN 7000 series allows service providers to protect and expand their current Layer 2 investments and migrate their existing and new services to IP/MPLS-based converged backbones.

CIENA's ONLINE Edge multiservice platform delivers service transparency through intelligent coarse wavelength division multiplexing (CWDM) technology combined with industry-leading service aggregation. The compact and modular ONLINE Edge is designed for enterprises and service providers who require a mix of traditional TDM and a broad range of carrier-class, high-bandwidth native data and storage services over a single optical infrastructure.

ABOUT CIENA

CIENA Corporation delivers innovative network solutions to the world's largest service providers and enterprises, increasing the cost-efficiency of current services while enabling the creation of new carrier-class data services built upon the existing network infrastructure. Additional information about CIENA can be found at www.ciena.com.

NOTE TO INVESTORS

This press release contains certain forward-looking statements based on current expectations, forecasts and assumptions of CIENA (the Company) that involve risks and uncertainties. Forward-looking statements in this release, including but not limited to the features and benefits of CIENA'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 19, 2004. Forward looking statements include statements regarding the Company's expectations, beliefs, intentions or strategies regarding the future and can be identified by forward looking words such as "anticipate," "believe," "could," "estimate," "expect," "intend," "may," "should," "will," and "would" or similar words. The Company assumes no obligation to update the information included in this press release, whether as a result of new information, future events or otherwise.