LOS ANGELES, Calif. -- March 10, 1998 -- TCG CERFnet, the data and Internet service business unit of Teleport Communications Group, Inc. (NASDAQ: TCGI) announced today TCG CERFnet's participation in the Cisco Powered Network (CPN) Program. To qualify for the program, participants must have the equipment, staff, and quality processes in place to meet Cisco Systems, Inc.'s rigorous criteria for reliable, high-quality network services. The CPN program provides businesses with the assurance that participants are committed to developing and maintaining the highest degree of service quality for their customers.

TCG CERFnet, one of the country's leading data, Internet and Web hosting service providers, and Cisco, the worldwide leader in networking for the Internet, have both been involved in advancing Internet and networking technology for nearly a decade and have a long-standing relationship.

Fault-tolerant Backbone

TCG CERFnet has been using Cisco routers throughout its network since it was founded in 1988. To ensure that there are no single points of failure, TCG CERFnet 's OC3 national backbone is fully redundant. Housed in telco-grade "hardened" facilities that have 7x24 secured access, each backbone node is equipped with reliable, high-performance Cisco 7513 or 7000 routers with silicon switch engines. Each backbone node is also served by at least two DS3- or OC3-speed circuits which are delivered on protected, self-healing SONET rings to ensure complete physical diversity. The circuits are then connected to two other TCG CERFnet backbone nodes outside the local area for optimum redundancy and routing efficiency.

Cisco-Powered Network

TCG CERFnet includes Cisco routers with its bundled Internet services. Cisco 2524 routers are included with its T1 tiered and metered leased line services as well as its 56Kbps and 128Kbps Frame Relay services. Cisco 4700 routers are included with TCG CERFnet's bundled T3 tiered and metered leased-line services. TCG CERFnet also uses the Cisco Catalyst. 5500 switch with Route Switch Modules (RSM) for its OmniLANsm transparent LAN connectivity solutions, as well as its OmniStreamsm native ATM transport data services, and OmniRingsm private line services. Chosen for its media-independent architecture, the Catalyst 5500 supports all legacy LAN and Asynchronous Transfer Mode (ATM) switching technologies through a wide range of Ethernet, Fast Ethernet, Fiber Distributed Data Interface (FDDI), Token Ring, and ATM switch modules.

Early this year, TCG CERFnet also collaborated with Cisco in deploying Web Chorussm, a new SuperSite architecture that incorporates Cisco's Distributed Director and Local Director load-balancing products. These products enable TCG CERFnet to match server capacity with demand; requests are transparently routed to the nearest, most responsive servers at TCG CERFnet's fully redundant SuperSites which are strategically located across the country.

Expansion Nationwide

TCG CERFnet also embarked on a vigorous expansion program early this year, leveraging TCG's more than 8,600 miles of fiber network backbone to bring its data, Internet and Web hosting services to major markets from coast to coast. Today, TCG CERFnet offers businesses in 32 key cities with cost-effective solutions for their current requirements while ensuring the scalability options they need to accommodate future requirements.

"We're rolling out a complete, one-stop solution for a wide range of Internet, Intranet and Extranet services as well as Web, voice, data and video services in cities across the nation," said Pushpendra Mohta, executive vice president of TCG CERFnet. "Our participation in the Cisco Powered Network program will be a definite asset, because prospective customers will have the confidence of knowing that we meet the industry's most rigorous requirements for reliable, high-performance services."

"TCG CERFnet is an industry innovator at the forefront of a new emerging business model that will provide true end-to-end corporate support," said Don Listwin, senior vice president of Cisco System's Service Provider Line of business. "Combined, TCG CERFnet and Cisco offer a proven solution to accommodating high-volume traffic while ensuring superior reliability and quality of service."

About TCG CERFnet

TCG CERFnet is the data and Internet service business unit of Teleport Communications Group Inc. (NASDAQ: TCGI). TCG is the nation's first and largest provider of localtelecommunications services using both fiber-optic and broadband wireless services including an array of advanced voice, data, video and Internet services. TCG operates in 58 major markets and, with the completion of the development of eight new networks, will expand to 66 markets. For complete information on TCG CERFnet's data, Internet and Web hosting services, contact TCG CERFnet at (888) CERFNET; (619) 812-5000; e-mail info@cerf.net or visit TCG CERFnet's Web site at URL: http://www.cerf.net/.

Cisco Systems

Cisco Systems, Inc. (NASDAQ:CSCO) is theworldwide leader in networking for the Internet. News and information areavailable athttp://www.cisco.com.

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