Metromedia Fiber Network, Inc., (MFN) (Nasdaq: MFNX) a provider of optical IP Internet infrastructure within key metropolitan areas domestically and internationally, and provider of data centers and Internet connectivity through its AboveNet Communications subsidiary, now offers a service level agreement (SLA) guaranteeing 100% IP network availability to all customers co-located in an AboveNet Internet Service Exchange (ISX) facility.

MFN's extensive fiber-optic network, combined with AboveNet's co-location facilities, enables the company to provide network performance to back up the 100% SLA guarantee. The layered and regionalized network allows for isolation and seamless redundancy in case of network problems, as well as phasing of software and hardware upgrades to ensure continuous up-time. The ISX facilities provide the most advanced, fail-safe data center environment available, as well as superior Internet connectivity.

For customers, the SLA agreements will provide an additional sense of security and peace of mind when moving mission-critical applications to the Internet.

About Metromedia Fiber Network, Inc.:

Metromedia Fiber Network, Inc., a provider of end-to-end optical network solutions, offers virtually unlimited, unmetered bandwidth at a fixed cost. For more information, please visit www.mmfn.com.

About AboveNet:

AboveNet is the architect of the Internet Service Exchange (ISX), a network that provides co-location services and Internet connectivity for content providers, ISPs and application service providers. For more information on AboveNet, visit www.above.net.