QoS Algorithm for Localised Routing Based on Bandwidth as the Dominant Metric for Candidate Path Selection

Most of the Quality of Service (QoS) routing mechanisms involve periodic exchange of global state information which causes communication overheads. Therefore, localised routing is the method to avoid this problem. The network in this technique is inferred by the source nodes using statistics which are collected locally. The main aim of this paper is to present new localised algorithm to avoid some problems associated with the existing localised QoS routing algorithms and so generate better performance. The new localised routing algorithm called Highest Minimum Bandwidth routing (HMB) is introduced in this paper. The new algorithm is compared under different traffic loads and network topologies to the existing localised Credit Based Routing (CBR) and the global Widest-Shortest-Path (WSP) routing algorithm, our algorithm shows better performance without undue increase in complexity. The selection of disjoint paths and recalculation of the set of candidate paths were used in our new algorithm and also applied on the existing algorithm CBR. There also was shown positive effect of dynamic path selection method on the performance of localised routing algorithm.