Fast and efficient routing algorithms for delay-bounded and dependable channels

Quality of Service (QoS) path computation techniques have assumed a lot of importance in recent years. The goal of QoS based routing is to find a path that meets the requested QoS requirements optimizing network utilization. Real-time and multimedia applications require QoS guarantees on timeliness of message delivery and failure-recovery delay. With these goals in mind we present two new routing algorithms. The first one is an efficient routing algorithm that finds a single path given an end-to-end delay. The second algorithm uses the first one in order to obtain the primary and backup paths for dependable channels guaranteeing the required end-to-end delay. Both algorithms maximize the admission of channels in a network and have low polynomial computational cost. We evaluated these algorithms using Differentiated Services Expedited Forwarding (EF) class of service. The experiments show that these algorithms are very efficient: the admission rate (the number of channels that a network can accept) is practically the same as using the optimal routing algorithm and the computational cost is very low.