On the benefits of using a large IXP as an internet vantage point

In the context of measuring the Internet, a long-standing question has been whether there exist well-localized physical entities in today's network where traffic from a representative cross-section of the constituents of the Internet can be observed at a fine-enough granularity to paint an accurate and informative picture of how these constituents shape and impact much of the structure and evolution of today's Internet and the actual traffic it carries. In this paper, we first answer this question in the affirmative by mining 17 weeks of continuous sFlow data from one of the largest European IXPs. Examining these weekly snapshots, we discover a vantage point with excellent visibility into the Internet, seeing week-in and week-out traffic from all 42K+ routed ASes, almost all 450K+ routed prefixes, from close to 1.5M servers, and around a quarter billion IPs from all around the globe. Second, to show the potential of such vantage points, we analyze the server-related portion of the traffic at this IXP, identify the server IPs and cluster them according to the organizations responsible for delivering the content. In the process, we observe a clear trend among many of the critical Internet players towards network heterogenization; that is, either hosting servers of third-party networks in their own infrastructures or pursuing massive deployments of their own servers in strategically chosen third-party networks. While the latter is a well-known business strategy of companies such as Akamai, Google, and Netflix, we show in this paper the extent of network heterogenization in today's Internet and illustrate how it enriches the traditional, largely traffic-agnostic AS-level view of the Internet.