Considering Packet Loss Probability in Fault-Tolerant OSPF Routing

Interior gateway protocols such as OSPF associate a weight with each network link and then compute shortest paths. The weights optimization is done by solving the Weight Setting Problem (WSP). One drawback of current approaches is that they disregard factors like packet loss probability. Most approaches also ignore network dynamics. When a router or link fails, there is a redistribution of traffic to alternate paths, increasing the network load and thus resulting in congestion. This paper presents a strategy for solving the WSP considering link congestion, packet loss and fault tolerance. Two meta-heuristics (simulated annealing and harmony search) are applied to yield good quality and high performance solutions. Applications under different scenarios show the effectiveness of the proposed approach.