Complexity of Internet Interconnections: Technology, Incentives and Implications for Policy

Abstract

End-to-End (E2E) packet delivery in the Internet is achieved through a system of interconnections between heterogeneous entities called Autonomous Systems (ASes). As of March 2007, there were over 26,000 in use [ASN07]. Most ASes are ISPs, but they also include enterprises, governmental or educational institutions, and increasingly large content providers with mostly outbound traffic such as Google, Yahoo, and YouTube as well as overlay content distribution networks such as Akamai and Limelight [CLA05]. Each AS controls or administers its own domain of addresses but ASes must physically interconnect to provide end-to-end connectivity across the Internet. Interconnection is not only important from a reachability perspective but also quality and performance perspective, because how ASes interconnect, both physically and contractually, determines how packets are routed and impacts the quality and choice of services that may be supported. The initial pattern of AS interconnection in the Internet was relatively simple, involving mainly ISPs with a balanced mixture of inbound and outbound traffic. One goal of this paper is to demonstrate how changing market conditions and industrial organization of the Internet have