Characterization of the Internet at the AS Level

Modeling the Internet topology is an important open problem that has attracted researchers attention in the past few years. This report presents an overview of the different research activities related to Internet characterization at the AS level. It describes the different methods used to measure the Internet AS topology, as well as some of the recent visualization and modeling techniques. It then outlines the different topological properties inferred from AS graphs, and their significance. In particular, it focuses on the AS degree distribution demonstrating its high variability using snapshots of AS topology, and attempts to explain its causes. Finally, it presents a software tool specially developed to facilitate manipulation and analysis of AS topology data.