目前因特网协议（ＩＰ）组播路由协议在结构上可分为基于源和基于组的两类转发树结构．把这两种组播路由结构在扩展性能、对单播路由算法的依赖性、业务量拥塞特性、网络的额外开支量以及对源ＩＰ地址的依赖性等方面进行分析比较，指出它们在不同应用场合的优缺点，为两种结构的路由协议相互结合、取长补短奠定了基础 At present, the Internet Protocol (IP) multicast routing protocol is structurally divided into two types of forwarding tree structure based on source and group. The two multicast routing structures are analyzed and compared in terms of scalability, dependency on unicast routing algorithms, traffic congestion, network overhead, and reliance on source IP addresses. The advantages and disadvantages of the occasion for the two structure of the routing protocols combined with each other, learn from each other to lay the foundation