Improving BGP Convergence Time via MRAI Timer

The Border Gateway Protocol (BGP) is the path vector protocol that routes inter-domain traffic, connecting Autonomous Systems (AS’s) together to form the decentralized backbone of the Internet. In the event of a network failure, BGP can take minutes to converge under default settings. With the route withdrawal rate limit (WRATE) change in the new BGP specification, the effect of the Minimum Route Advertisement Interval (MRAI) timer on convergence time needs to be re-evaluated. This paper shows that the reduction of the MRAI timer remains critical to the improvement of BGP convergence time. This paper also shows that while WRATE is not effective in improving convergence time, it reduces the number of transient loops and messages on the network at the optimal MRAI value.