An analysis of network reachability using BGP data

Though there have been extensive studies on AS and ISP level topologies, BGP path stability and overall path variations and churn, there is comparatively little data on the behavior of overall reachability in the Internet. We can explain reachability as a measure of path robustness over time, and thus as a significant measure of the general quality of the infrastructure. Our results show that BGP views across different collector route servers, through our period of study, are very homogeneous, and that variations in overall reachability are relatively small. We interpret these observations as indications that overall reachability is robust, and found it to be particularly good in G7 countries, perhaps due to a better communications infrastructure.