earticle

영어

Open Shortest Path First (OSPF) is a popular link state routing protocol widely used in Internet infrastructure. OSPF implements several timers to limit the protocol overhead. With these timers, it usually takes several tens of seconds for OSPF network to recover from a failure. The convergence time is delayed mainly by the timers of failure detection and routing calculation scheduling. In this paper we analyze OSPF convergence behavior in presence of multiple failures, where the interactions between failure detection and routing calculation scheduling could generate complicated dynamics during convergence process. We also present experimental study to understand the impact of multiple failures on convergence. The results demonstrate that multiple failures have a greater chance to delay the convergence. This suggests that operators should take it into account while configuring OSPF network.