AboveNet Announces CAT Technology as First Reseller to Deliver Leading E-commerce Solutions in 'Sun Pavilion;' Announcement Made in Support of Sun's ServiceProvider.com Initiative.

NEW YORK--(BUSINESS WIRE)--May 5, 1999--

AboveNet Communications Inc. (Nasdaq: ABOV), the architect of a global one-hop network that brings together high-bandwidth content sites and ISPs in centralized co-location facilities, and CAT Technology, Inc., a leading systems integrator for Sun Microsystems, Inc., today announced a reseller relationship that provides comprehensive e-commerce Internet solutions to businesses wishing to expand their online presence quickly and efficiently.

The two companies made the announcement in support of Sun's ServiceProvider.com launch, held today at New York's Millennium Broadway Hotel. Sun's ServiceProvider.com Initiative is a new set of products, services and business practices designed to promote the service provider business model. Sun's established network computing leadership makes it an ideal company to provide the necessary infrastructure, which enables service providers to focus on capturing new customers and developing the value-added services its customers require.

In the "Sun Pavilion" area of AboveNet's San Jose Internet Service Exchange, CAT Technology will offer a package that combines its software and integration services with Sun Enterprise(TM) servers and AboveNet's co-location and connectivity services.

AboveNet's Internet connectivity services are designed to deliver a fast, reliable and scalable Internet solution for business-critical and high bandwidth applications. Its ISX facilities co-locate content providers and ISPs together to deliver connectivity and access to the AboveNet Global One-Hop Network(TM).

"This relationship offers businesses a highly integrated and convenient solution for getting online -- it is an ideal combination of high-performance computing, scalable bandwidth and integration services," said Richard Crouch, president and chief executive officer of CAT Technology. "We chose Sun systems and the Solaris(TM) operating environment because they are a leader in their industry and only AboveNet has shown to have the Internet connectivity and network performance to match Sun's equipment and services. AboveNet also has the technical expertise and responsive support team to compliment our own service offering which allows us to offer a superior solution."

"We are pleased to welcome CAT Technology to our growing number of industry leading technology providers working with us to offer superior Internet connectivity," said David Dembitz, senior vice president of sales and marketing at AboveNet. "Our ISX network architecture is designed to deliver the clean bandwidth and minimal latency critical to business success on the Internet."

About CAT Technology, Inc.

CAT Technology, Inc. is a leading solution provider of highly scalable, highly available, web-based systems utilizing Java technology. One of the largest Elite certified Sun Microsystems Value Added Resellers, CAT is also a Sun Authorized Java Center, Premier Cisco Systems Reseller, and Oracle/Informix/Veritas Reseller. CAT's "Total Solution" approach spans a spectrum of value added services. Java based web design, diagnostic, security, and traffic solutions, as well as integration, system relocation, co-hosting, and multi-service network services such as voice over IP and voice enabled web, are CAT Technology core competencies now available to AboveNet customers.

About AboveNet Communications Inc.

AboveNet Communications, Inc. is a leading provider of Internet connectivity and co-location solutions for high bandwidth and business-critical Internet applications. 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 and ISPs. The AboveNet Global One-Hop Network is designed to deliver fast, scalable and reliable connections to the Internet and improve the Internet experience for end-users. 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 and its service offerings visit the company's Web site at www.above.net or 1-800-475-2733.

Note to Editors: 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.

Sun, the Sun logo, Sun Microsystems, Solaris, and Enterprise are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and in other countries.

The statements contained in this press release that are not purely historical are forward looking statements within the meaning of section 21E of the Securities Exchange Act of 1934, as amended, including statements regarding the company's expectations, beliefs, hopes, intention or strategies regarding the future. Factors that could cause or contribute to such differences include risks related to intense competition, the emerging market for co-location and connectivity services, risks related to International expansion, the uncertainty of the acceptance of the Company's services, network scalability and other factors and risks discussed in the company's registration statement on form S-1, filed with the Securities and Exchange Commission on April 7, 1999 and other reports filed from time to time with the Securities Exchange Commission.