Metromedia Fiber Network Deploys Largest and Most Advanced Continuous Power Supply System in North America

Business Wire, May 23, 2000

Business Editors/High-Tech Writers

NEW YORK--(BUSINESS WIRE)--May 23, 2000

MFN's Customers Benefit from Maximum Power Reliability,

Reinforcing Network Availability and Performance

Metromedia Fiber Network, Inc.'s (MFN) (Nasdaq: MFNX) subsidiary AboveNet Communications, Inc. continues to set the pace as an Internet technology leader by deploying the largest installation of advanced continuous power supply (CPS) systems in North America throughout the company's Internet Service Exchange (ISX) data centers. The installation of these state-of-the-art CPS systems reflect MFN's commitment to provide the most robust and reliable network environment for its customers.

MFN first deployed the CPS system at its second Virginia ISX facility in Q1 of this year. The company's new San Jose II facility is equipped with multiple CPS units and has been engineered to provide N 2 redundancy. As part of Metromedia Fiber Network's $1.4 billion infrastructure expansion, all MFN ISX facilities will be designed around the CPS system, including the first-ever CPS installation in the greater New York City area.

"After an extensive evaluation, we concluded that the CPS system is the superior solution to our mission-critical power needs," said Jeff Monroe, vice president of real estate, design & construction for MFN. "The best network connection available demands nothing less than the best power system available. By deploying the CPS, we solidify our commitment to our customers and set a new industry standard which others are sure to follow."

The unique, sophisticated design of the CPS uses no batteries and delivers power through a combination of active on-line generators, flywheels, motor generators, and diesel engines. The system is easy to maintain and seamlessly reliable. In the event of a utility outage, the load is maintained via the inertial energy contained within the flywheel. Concurrently the diesel generator is activated and engaged to assume support of the critical and essential power loads. This process takes place in less than two seconds. The system can deliver a minimum of 40 hours of full-load backup power from the basic fuel capacity that is stored on site. To ensure additional fuel in the event of a major emergency, MFN has contracts with multiple fuel vendors.

MFN's ISX facilities are an integral part of its planned deployment of an all-optical IP architecture over a dedicated fiber-optic network that reaches throughout the local loop in 67 cities in North America and Europe. This expansive network will provide MFN customers with exceptionally fast and reliable connectivity to the Internet. The network will reach up to multi-terabit-per-second capacity and when combined with MFN's world-class co-location facilities, will provide an ideal IP infrastructure for a variety of Internet focused companies.

About Metromedia Fiber Network, Inc.

Metromedia Fiber Network, Inc., the leading provider of end-to-end optical network solutions, is revolutionizing the fiber optic industry. By offering virtually unlimited, unmetered bandwidth at a fixed cost, Metromedia Fiber Network is eliminating the bandwidth barrier and redefining the way broadband capacity is sold. Metromedia Fiber Network is extending metropolitan fiber optic infrastructure to the end user in strategic top-tier markets, enabling its customers to implement the latest data, video, Internet and multimedia applications. In addition to its current expansion in 51 cities in North America, Metromedia Fiber Network is establishing an international presence with planned fiber optic network builds in 16 cities throughout Europe. For more information about Metromedia Fiber Network, please visit the company's Web site at www.mmfn.com.

Together with its subsidiaries, AboveNet Communications, Inc., a leading provider of Internet connectivity and co-location solutions for high bandwidth and business-critical applications and Paix.net, Inc., the leading neutral Internet Exchange, Metromedia Fiber Network is unleashing the full potential of the Internet. The combined company facilitates the explosive growth of e-commerce and advanced Internet applications by delivering secure, reliable and scalable optical networks and IP services to Internet content and service providers, carriers and enterprise users worldwide. AboveNet is the architect of the Internet Service Exchange (ISX) -- a world class network that provides co-location services and Internet connectivity for content providers, ISPs and application service providers. With its Tier 1 status and ISO 9002 certification, AboveNet is seeking to serve the global community of the Internet. For more information on AboveNet's service offering call 800/475-2733 or visit the company's Web site at www.above.net.

AboveNet, Internet Service Exchange, ISX, and AboveNet Global One-Hop Network are trademarks of AboveNet Communications, Inc. All other company or brand names may be trademarks of the respective companies with which they are associated.

This news release contains certain forward-looking statements that involve risks and uncertainties. Factors that could cause or contribute to such risks and uncertainties include, but are not limited to, general economic and business conditions, competition, changes in technology and methods of marketing, and various other factors beyond the Company's control. This also includes such factors as described from time to time in the SEC filings by Metromedia Fiber Network, including the most recently filed Forms S-3, 10-K and 10-Q