Switching Time Measurement and Optimization Issues in GNU Quagga Routing Software

OSPF (Open Shortest Path First) is a widely used intra-domain routing protocol in IP networks. Processing delays in OSPF implementations impact the time needed for both intra-domain and inter-domain routing to reconverge after a topology change. In this paper we introduce a performance index, referred to as the switching time, allowing the router reconverge to be characterized when network topology changes occur. We propose a test methodology in order to measure the introduced performance index in router realized with the Personal Computer hardware and equipped with Quagga, the most used open routing software. An optimization of the Quagga routing software has been performed and better performance has been obtained in terms of switching time.