Renesys Corporation Measures Impact of North American ISP Consolidation Using Market Intelligence Solution; Latest Customer Base Index Report Indicates Significant Shifts in Competitive Service Provider Landscape.

MANCHESTER, N.H. -- Renesys Corporation, a leading provider of next-generation Internet Routing and Market Intelligence solutions, today released the third in a series of reports comparing carriers worldwide. The latest Customer Base Index report examines the pivotal role that recent consolidation activity has played in reshaping the North American Internet service provider market.

Specifically, Renesys tracked two recent developments: Level 3 Communications Inc. losing Verizon Internet Services as a customer due to their purchase of MCI, and Sprint Nextel Corp. losing SBC as a customer due to its integration with AT&T. The effects of these events are measured by the Renesys Internet Index.

The Renesys Internet Index tracks observed trends in Internet structure, using information from the global routing tables to determine which network service providers are most critically important for reaching customer networks in each of the geographic markets that make up the global Internet. The Renesys Customer Base Index objectively measures the number and size of networks observed to be reachable on any given day via each provider's transit services, in each of three categories: Retail, Wholesale, and Backbone transit.

The following are the top 10 service providers in each category for the month leading up to July 26,2006:

North American Retail Customer Base
(retail customers are defined as those networks directly originated by
a service provider, or by their enterprise customers who have no
further autonomous systems downstream)

1.    AT&T WorldNet Services (AS 7018)
2.    Sprint (AS 1239)
3.    UUNET Technologies, Inc. (AS 701)
4.    Level 3 Communications, LLC (AS 3356)
5.    Qwest (AS 209)
6.    Savvis (AS 3561)
7.(+1)Cogent Communications (AS 174)
8.(-1)SBC Internet Services (AS 7132)
9.    Verizon Internet Services Inc. (AS 19262)
10.   Time Warner Telecom, Inc. (AS 4323)

North American Wholesale Customer Base
(wholesale customers are defined as those service providers that
resell IP transit services to retail service providers in a selected
market)

1.    Level 3 Communications, LLC (AS 3356)
2.    UUNET Technologies, Inc. (AS 701)
3.    AT&T WorldNet Services (AS 7018)
4.    Sprint (AS 1239)
5.(+1)Qwest (AS 209)
6.(-1)Cogent Communications (AS 174)
7.    Savvis (AS 3561)
8.    AOL Transit Data Network (AS 1668)
9.    BellSouth.net IP Backbone (AS 6389)
10.   Global Crossing (AS 3549)

Note: AOL Transit Data Network at #8 is effectively a wholesale
provider for the two thousand or so networks represented by the
extended AOL network family (primarily Road Runner, but also Netscape,
CompuServe, Time Warner, Turner Broadcasting, etc)

North American Backbone Customer Base
(backbone customers are defined as service providers that resell IP
transit services to wholesale service providers, or to other backbone
service providers, in a selected market)

1.    Level 3 Communications, LLC (AS 3356)
2.(+1)UUNET Technologies, Inc. (AS 701)
3.(-1)Sprint (AS 1239)
4.    AT&T WorldNet Services (AS 7018)
5.(+1)Savvis (AS 3561)
6.(-1)NTT America, Inc. (AS 2914)
7.    Qwest (AS 209)
8.    Global Crossing (AS 3549)
9.    Level 3 Communications, Inc. (AS 7911)
10.   Cogent Communications (AS 174)

Renesys Market Intelligence (RMI) is the first and only continuously updated information resource of its kind. Based on the evolution of the global service provider marketplace, it includes live data from global routing tables, which is therefore used to include real-time maps of more than 180,000 networks and 30,000 organizations worldwide. RMI showcases relative strengths and weaknesses of competing service providers, and includes global, national and regional rankings of customer growth based on the changing number and quality of networks to which the competitor is linked.

Renesys' Market Intelligence provides an objective, reliable view into the following metrics:

--Which service providers have the most customer networks?

--Which service providers are acquiring customer networks at the fastest rate?

--Which service providers are experiencing the least customer churn?

--Which service providers have the most customers with only one link to the Internet?

--Which service providers connect to the most customer networks, both directly and through peering relationships?

About Renesys Corporation

Renesys offers the industry's first Internet performance monitoring and analysis solution that provides Internet intelligence for competitive advantage. The company gives service providers, government agencies and Global 2000 organizations a real-time view into the Global Internet as it affects their business. Only with Renesys can customers have a new level of speed and agility in managing the Internet climate outside the four walls of the organization, resulting in minimal downtime between customers, partners and other stakeholders. Renesys was founded in 2000 and is based in Manchester, NH. For more information, visit www.renesys.com.