延时受限的覆盖多播路由协议及优化策略

研究了有度和延时约束的覆盖多播路由问题,提出了一个新的覆盖多播路由协议--度、延时约束树协议(DDCTP).该协议采用分布式和树优先的策略,使多播组成员之间能自组织地构建一棵基于源的覆盖多播树.DDCTP遵循协议机制和优化策略相分离的设计原则,可独立地采用不同的优化策略而无需修改协议框架.在此基础上,提出并比较了多种优化策略.仿真实验表明,综合考虑空闲度、延时距离和树上延时的优化策略能获得最高的节点接纳率,但也使多播树占用较多的网络资源.实际应用可根据具体情况,选择不同的优化策略,在节点接纳率和网络资源占用量之间进行折衷.

Delay constrained overlay multicast routing protocol and its optimization strategies

The degree and delay constrained routing problem in overlay multicast is studied,and a new overlay multicast routing protocol called degree and delay constrained tree protocol(DDCTP) is proposed.Adopting distributed and treefirst strategies,the protocol enables members of a multicast group to self-organize into a source-based overlay multicast tree.With the separation principle of protocol mechanism and optimization strategy,DDCTP can use different optimization strategies independently without changing the framework of the protocol.Further more,several optimization strategies are proposed and compared.The simulation results show that the strategy,which takes the free degree,delay distance and tree delay synthetically into account,can achieve the highest admission rate of member,however the network resource usage of the multicast tree will be higher.In practice,application can make a trade-off between admission rate and resource usage by choosing different optimization strategies.