Optimizing post-failure network performance for IP fast reroute using tunnels

Abstract

IP Fast ReRoute (FRR) mechanisms have been proposed to achieve fast failover for supporting Quality of Services (QoS) assurance. However, these mechanisms do not consider network performance after affected traffic is rerouted onto repair paths. As a result, QoS deterioration may still happen due to post-failure traffic congestion in the network, which nullifies the effectiveness of IP FRR. In this paper, by considering IP tunneling as the underlying IP FRR mechanism, we proposed an efficient algorithm to judiciously select tunnel endpoints such that the network performance is optimized after the repair paths are activated for rerouting. According to the simulation results using real operational network topologies and traffic matrices, the algorithm achieves significant improvement on post-failure load balancing compared to the traditional IGP re-convergence and plain tunnel endpoint selection without such consideration.