Research Of QoS Routing Algorithm Over IP Network

With the fast development of real-time and multimedia applications in high-speed Internet, the high-efficient quality-of-service(QoS)support is required in the communication network.But the traditional "best-effect" network mechanism can not guarantee the QoS communication. The research in these years shows that the algorithm of network routing plays an important part in providing quality-of-service guarantees, so the QoS-based routing algorithm becomes one of the nuclear network problems.This dissertation introduces the background of the QoS routing technology and it′s present research status quo and basic conception of QoS routing algorithm and relevant knowledge. Then summarize and classify the QoS routing algorithms. On the basis of in-depth analysis of the traditional Dijkstra algorithm, the idea of using the m-heap to improve the Dijkstra algorithm is consummated. It is proved again in this paper that when m equals to 4, the m-heap algorithm can gain the highest efficiency, and the time complexity of Dijkstra algorithm can be reduced to O ( n log 4n ).Under multiple QoS constraints analyze the advantages and disadvantages of Fallback algorithm based on the shortest path algorithm. Put forward the multiple constraints QoS routing algorithm based on the 4-heap and improved Fallback algorithm to solve the delay and bandwidth-constrained least-cost routing problem. Reduce the time of computing the shortest path and reduce double-counting time spent on the shortest path according to QoS constraints. Take an example to analyze the process of QoS routing algorithm based on the multiple QoS constraints routing model. In the simulation environment (NS-2), according to the topology map, doing simulation tests proves that there is a big upgrade of it′s performance. Simulation experiments show that, the algorithm meets user′s requirements of bandwidth and delay very well. Finally, summarize the paper and point out the hot issues of QoS routing which need to research.