Automating Geography-Based Redirection

Reliability and performance considerations have led to widespread use of mirror sites for content delivery. Based on measurements, redirection to a geographically closer replica is indeed valuable. Given an IP address, a mapping tool has to return the geographic location of the host to which the IP address has been assigned. This is a difficult problem because an IP address does not inherently possess any indication of geographic location. GeoTrack is a traceroute-based tool that tries to infer location based on the DNS names of the target host or other nearby network nodes. An IP to location mapping tool, like GeoTrack, would allow various location-aware applications on the Internet. For instance, web browser would be able to automatically select the closest mirror servers by running GeoTrack on multiple IP addresses. This introduces the problem of generating high overhead and additional Internet traffic since traceroute sends a packet to each hop on a network path. Using distribution based on several traceroute logs, we develop an algorithm that reduces the number of packets transmitted per traceroute from the average of 15-20 packets per traceroute to 3-5 packets per traceroute.