应用层组播动态调整问题的研究

Research on dynamic adjust of application-layer multicast

通过分析影响应用层组播性能的因素及这些因素的变化对组播性能的影响,指出了在组播过程中随着成员的加入退出、网络波动和结点处理能力的变化,组播的结构和性能都会发生变化。在组播开始时构建的组播树无法适应这些变化,导致了组播性能的下降。针对该问题提出了在组播过程中根据变化调整组播树的结构,并给出了一种改善组播性能的动态调整算法。实验结果表明,动态调整算法能够有效的反映组播的结构、网络状况和结点情况,改善组播的性能。

After analyzing the factors that influence the performance of application-layer multicast, a problem that may reduce the performance of multicast is proposed. The multicast structure and performance has changed as the members＇ join and quite, the chum of network and the variable ofmulticast members＇ process ability during the application layer multicast. The tree constructed initially cannot adapt to these changes, which leads to reduce the performance of multicast. To improve the multicast tree＇ s performance, a method called dynamic adjust of application-layer multicast, which adjust the multicast tree＇ s structure according to the changes of factors that influence multicast, is proposed. An algorithm of improving multicast tree is also pointed out. Finally, the feasibility of the method and algorithm is validated by experiment.