The Internet AS-Level Topology: Three Data Sources and One Definitive Metric

TL;DR

This paper compares Internet AS topologies derived from traceroutes, BGP, and WHOIS data, identifying the joint degree distribution as a key metric and providing datasets for future research validation.

Contribution

It systematically analyzes three major data sources for Internet AS topologies and highlights the joint degree distribution as a fundamental characteristic.

Findings

Traceroute and BGP topologies are similar, WHOIS differs significantly.

Joint degree distribution characterizes AS topologies effectively.

Data collection methods influence topology metrics.

Abstract

We calculate an extensive set of characteristics for Internet AS topologies extracted from the three data sources most frequently used by the research community: traceroutes, BGP, and WHOIS. We discover that traceroute and BGP topologies are similar to one another but differ substantially from the WHOIS topology. Among the widely considered metrics, we find that the joint degree distribution appears to fundamentally characterize Internet AS topologies as well as narrowly define values for other important metrics. We discuss the interplay between the specifics of the three data collection mechanisms and the resulting topology views. In particular, we show how the data collection peculiarities explain differences in the resulting joint degree distributions of the respective topologies. Finally, we release to the community the input topology datasets, along with the scripts and output of our calculations. This supplement should enable researchers to validate their models against real data and to make more informed selection of topology data sources for their specific needs.