An Experimental Analysis of BGP Convergence Time

The Border Gateway Protocol (BGP) is the routing protocol used to maintain connectivity between autonomous systems in the Internet. Empirical measurements have shown that there can be considerable delay in BGP convergence after routing changes. One contributing factor in this delay is a BGP-specific timer used to limit the rate at which routing messages are transmitted. We use the SSFNet simulator to explore the relationship between convergence time and the configuration of this timer. For each simple network topology simulated, we observe that there is an optimal value for the rate-limiting timer that minimizes convergence time.