The Effect of Routing-Update Time on Network´s Performability

By occurring failures in computer networks, routing protocols are triggered to update routing and forwarding tables. Because of invalid tables during update-time, transient loop may occur and packet-drop rate and end- to-end delay increase which means that the quality of service decreases. This paper studies the effect of routing- tables update-time on networks´ performability, i.e. the ability of network to deliver services at predefined level. A sample network is studied and the simulation results show that faster updates of routing table, improve network´s performability in the presence of failures. Since it may not worth or even be practical to accelerate all routers in the network, this paper suggests finding bottleneck routers and accelerating them in order to improve the performability of the network. The simulation results show that by speeding-up the bottleneck routers of the network, instead of all routers, the desired performability could be achieved.