Inferring Internet AS Relationships Based on BGP Routing Policies

TL;DR

This paper introduces a novel method for inferring Internet AS relationships by analyzing BGP routing policies, revealing complex relationship types and improving understanding of Internet routing dynamics.

Contribution

It presents a new approach using BGP attributes Communities and Locpref to infer AS relationships, including special types like hybrid and backup links, based on extensive BGP data analysis.

Findings

Inferred AS relationships for 39% of links in the dataset.

Identified all Tier-1 links and most Tier-1 to Tier-2 links.

Discovered various special relationships such as hybrid and backup links.

Abstract

The type of business relationships between the Internet autonomous systems (AS) determines the BGP inter-domain routing. Previous works on inferring AS relationships relied on the connectivity information between ASes. In this paper we infer AS relationships by analysing the routing polices of ASes encoded in the BGP attributes Communities and the Locpref. We accumulate BGP data from RouteViews, RIPE RIS and the public Route Servers in August 2010 and February 2011. Based on the routing policies extracted from data of the two BGP attributes, we obtain AS relationships for 39% links in our data, which include all links among the Tier-1 ASes and most links between Tier-1 and Tier-2 ASes. We also reveal a number of special AS relationships, namely the hybrid relationship, the partial-transit relationship, the indirect peering relationship and the backup links. These special relationships are relevant to a better understanding of the Internet routing. Our work provides a profound methodological progress for inferring the AS relationships.