The Optimal Rate-Limiting Timer of BGP for Routing Convergence

Abstract

BGP might experience a lengthy path exploration process to reach the convergence after the routing changes [1]. [2] found that the BGP rate-limiting timer-MinRouteAdvertisementInterval (MRAI) has an optimal value M o that achieves the best trade-off between the stability and the convergence speed. In this paper, with the aid of a timed BGP model, we investigate the effects of MRAI and its optimal value M o for the BGP convergence process. We find that an adequately long MRAI timer can batch-remove candidate paths and ensure the routing stability in the convergence process. There exists a minimal MRAI M s that achieves the effect, which is also the upper bound of M o and provides an approximation of M o . We calculate the approximations of M s for different settings and estimate the optimal MRAI for the Internet. According to the results, the optimal MRAI for the Internet might be 5-10 times less than the current default value used in the Internet. The simulations taken with SSFNet and the experiments conducted over the Planet-Lab demonstrate the correctness of our analysis.