Exploring the Internet Routing Registries to Augment AS-Level Topology

Despite substantial research efforts over the past decade, it remains a challenge to develop a complete and accurate view of the Internet Autonomous System (AS) level topology. Recent studies highlight that the incompleteness of the AS-level topology is greater than previously recognized. To mitigate the issue, we highlight the usefulness of the Internet Routing Registries (IRR), a set of databases used by ASes to register and share their inter-domain routing policies. We first propose a methodology to extract AS-level links (e.g., bilateral and multilateral peering links) from the IRR, extracting 3.1 M AS-level links; 48.7% of which can be matched with BGP, traceroute, or the cliques of Internet eXchange points (IXPs). Next, we find the active usage of the IRR by the member ASes of the IXPs, which helps us infer the peering matrices of large and small IXPs. Non-matching IRR AS links (51.3%) can be attributed to the limited coverage of BGP route collectors, especially in regions where local interconnections are heavily regulated, and to regional IXP interconnection policy dynamics.