An Improved Distributed QoS Routing Algorithm

In recent years, with the development of the streaming media technology, the quality of service is needed much higher than before. There are several metrics of QoS (quality of service), such as bandwidth, delay, delay jitter and cost. Therefore, how to choose a path to satisfy the QoS requirements and how to combine QoS routing with resource reservation become an essential part of network researches. Around the world, researchers and experts proposed many creative and practicable QoS routing algorithms. Though having some defects, these algorithms contribute a lot to network researches, and will be very efficient if they are used correctly.How to increase bandwidth admission ratio, namely is how to take in more connection request in a heavy network, and decrease waste of resources, that is an important performance of a distributed QoS routing. Aiming at solving these defects of the existing algorithms, in this paper, distributed QoS routing for multimedia traffic is researched. On the basis of increasing bandwidth admission ratio, the improved algorithm is extended to solve the metrics of delay and cost. Meanwhile, the link capacity, accumulated delay and traffic cost are analyzed in detail. In accordance to take link capacity as the condition of delay forwarding, the improved algorithm not only increases the bandwidth admission ratio, but also decreases the connection delay. And more, the improved algorithm decreases traffic cost because of taking the accumulated delay to decrease probe packet.To verify the improved algorithm, we run computer simulation through using bandwidth admission ratio, connecting delay and traffic cost. The results reveal that this improved algorithm has high call admission rates, low delay and low traffic cost in the heavy network.