ABSTRACT

Path fingerprinting is an essential component of applications that distinguish among different network paths, including path selection in overlay networks, multi-path routing, monitoring and diagnosis of network problems, and developing a deeper understanding of network behavior. This paper proposes a new approach to Internet path fingerprinting based on the distribution of end-toend packet-pair measurements. This approach allows detection of busy link sharing between two paths, even when those segments have low utilization and are not the paths ’ bottlenecks. While our fingerprints do not assure physically disjoint paths (since that requires information external to the network), they reflect the traffic and link characteristics of intermediate links. This methodology is therefore tolerant of opaque clouds such as VPNs, VLANs, or MPLS (unlike traceroute). Using analysis, simulation and investigation of ground truth about live paths and equipment, we explore the network factors that affect the fingerprints, and we introduce a simple method to compare them. Through measurements of up to a year over 15 Internet paths, we show that our fingerprints are both path-specific and persistent over periods of several months, making their collection and use for path selection feasible. 1