Revealing Utilization at Internet Interconnection Points

Abstract

The rapidly evolving nature of interconnection has sparked an increased interest in developing methods for gathering and collecting data about utilization at interconnection points. One mechanism, developed by DeepField Networks, allows Internet service providers (ISPs) to gather and aggregate utilization information using network flow statistics, standardized in the Internet Engineering Task Force as IPFIX. This report (1) provides an overview of the method that DeepField Networks is using to measure the utilization of various interconnection links between content providers and ISPs or links over which traffic between content and ISPs flow; and (2) surveys the findings from five months of Internet utilization data provided by seven participating ISPs—Bright House Networks, Comcast, Cox, Mediacom, Midco, Suddenlink, and Time Warner Cable—whose access networks represent about 50% of all U.S. broadband subscribers. We first discuss the problem of interconnection and utilization at interconnection points. We then discuss the basic operation of the measurement capabilities, including the collection and aggregation of traffic flow statistics (i.e., IPFIX records), providing an assessment of the scenarios where these aggregate measurements can yield accurate conclusions, as well as caveats associated with their collection. We assess the capabilities of flow statistics for measuring utilization, and we discuss the capabilities and limitations of the approach the aggregation techniques that the ISPs use both in providing data to us, and that we apply before making the data public. The dataset includes about 97% of the paid peering, settlement-free peering, and ISP-paid transit links of each of the participating ISPs. Initial analysis of the data—which comprises more than 1,000 link groups, representing the diverse and substitutable available routes—suggests that many interconnects have significant spare capacity, that this spare capacity exists both across ISPs in each region and in aggregate for any individual ISP, and that the aggregate utilization across interconnects is roughly 50% during peak periods.