Ciena's CoreStream Agility to Support Efficient Delivery of High-Growth Broadband Services for TELMEX; Long-Haul WDM Solution Added to Ciena Suite of Products Deployed in Telefonos de Mexico's Nationwide Long-Distance Network.

LINTHICUM, Md. -- Ciena(R) Corporation (Nasdaq:CIEN), the network specialist, today announced that CoreStream(R) Agility Optical Transmission System has been selected for deployment in Telefonos de Mexico S.A. de C.V.'s (TELMEX) (NYSE:TMX) nationwide long-distance network. As a strategic vendor to TELMEX, Mexico's leading telecommunications service provider, Ciena is providing the value of its FlexSelect(TM) architecture, which includes CoreStream Agility, for scalable capacity, design flexibility and network automation across the TELMEX network.

Designed with an open architecture that supports efficient transport of voice, video, and data, CoreStream Agility adds to Ciena's existing presence in the TELMEX long-distance network by delivering agile WDM (wavelength division multiplexing) for new levels of network flexibility and efficiency for the routing of signals and reconfiguration of network traffic via software.

"We are very pleased to expand our work with TELMEX and demonstrate in another large-scale deployment the innovative market value of our CoreStream platform and, more recently, our FlexSelect architecture," said Gary Smith, president and CEO, Ciena. "Our strategic relationship and success with TELMEX is a solid illustration of our commitment to global growth and serving the technology and economic needs of top-tier carrier customers."

For several years, Ciena's CoreDirector(R) multiservice switch has been deployed in TELMEX's premier next-generation Mexico City network, one of the largest metropolitan area networks in the world. CoreDirector is also deployed in additional TELMEX metro networks as well as its long-distance network to enable a single, fully-automated nationwide infrastructure.

CoreStream Agility is part of Ciena's FlexSelect Architecture, a standards-based network architectural solution that enables unprecedented flexibility, adaptability and manageability in automating delivery and management of any mix of services including SONET/SDH, OTN, Ethernet, storage and video. Capable of routing wavelengths up to speeds of 40G for long-haul and ultra long-haul (ULH) network routes, Ciena's CoreStream Agility implements an all-optical bypass to eliminate optical-electrical-optical (OEO) signal conversions and transceivers, allowing capital-cost savings that grow as the network scales. Additionally, the platform lowers ongoing operational costs by automating end-to-end service provisioning and management, inventory and resource tracking, and dynamic power management.

About Ciena's FlexSelect Architecture

FlexSelect is the only migration approach available today that blends the flexibility of software with high-performance programmable hardware for the delivery of any end-user service to any point on the network at any time. This mitigates the risks associated with convergence while maximizing all service opportunities and reducing costs. FlexSelect has been shown to reduce the overall total cost of ownership by more than 60 percent in actual service provider network analyses.

ABOUT CIENA

Ciena Corporation is the network specialist, focused on expanding the possibilities for its customers' networks while reducing their cost of ownership. The company's systems, software and services target and cure specific network pain points so that telcos, cable operators, governments and enterprises can best exploit the new applications that are driving their businesses forward. For more information, visit www.ciena.com.

NOTE TO INVESTORS

This press release contains certain forward-looking statements based on current expectations, forecasts and assumptions that involve risks and uncertainties. These statements are based on information available to the Company as of the date hereof; and Ciena's actual results could differ materially from those stated or implied, due to risks and uncertainties associated with its business, which include the risk factors disclosed in its Report on Form 10-K, which Ciena filed with the Securities and Exchange Commission on January 12, 2006. Forward-looking statements include statements regarding Ciena'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. Ciena assumes no obligation to update the information included in this press release, whether as a result of new information, future events or otherwise.