Impact of Internet exchange points on Internet topology evolution

The recent uncovering of a high number of peering links at Internet eXchange Point (IXP) locations across the world has made these exchange switches a critical component of the Internet Autonomous System (AS) level ecosystem. Studies concentrating on the Internet topology evolution have surmised that numerous links hidden at these exchange points hold the key towards solving the missing links problem in studying the evolution of the AS-level topology of the Internet. In this work, we study the effect of this set of hitherto unseen peering links on the visible Internet topology. Starting from a simple visual analysis and continuing with a more advanced graph based metric analysis, we conclude that IXP links follow power law increase characteristics while exhibiting definitive clustering characteristics. Moreover, these additional links affect the joint degree distributions of nodes with higher degrees while leaving most other types of nodes unchanged. We conclude that the currently inferred AS-level maps of the Internet demonstrate considerable variations with the incorporation of these new links and could eventually provide us a better understanding of Internet topology evolution.