Toronto Networking Seminar 2006

Fingerprinting Internet Paths using Packet Pair Dispersion

Christos Papadopoulos
University of Southern California

Date:  March 3,  3pm
Location: BA1210 (Bahen Center)


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.  We propose a new approach to Internet path fingerprinting based on the distribution of end-to-end 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 and simulation 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 distinct and persistent over periods of several months, making their collection and use for path selection feasible. 


Christos Papadopoulos is currently an assistant professor at the University of Southern California. He received his Ph.D. in Computer Science in 1999 from Washington University in St. Louis, MO. His interests include network security, router services, multimedia protocols and reliable multicast. Dr. Papadopoulos is a member of IMSC, where he conducts research in supporting immersive applications and a member of ISI, where he works on network security related projects.  In 2002, he received an NSF CAREER award to explore router services as a component of the next generation Internet architecture.