为了在一个通信网络中，找到多源点到多目的点的路由总代价最小的符合带宽-时延约束的路由集，根据服务质量组播路由的特点，结合遗传算法的寻优特性，采用一种求解带宽-时延约束的两层遗传算法的方法，进行了理论分析和实验验证，取得了多源点到多目的点组播路由集的代价数据。结果表明,所提出的算法可以有效找到多组播路由问题的优化解。

In order to find a route set from multi-source to multi-purpose nodes in a communication network in accordance with the bandwidth-delay constraints at minimum total cost according to the characteristics of quality of service multicast routing, combined with genetic algorithm optimization characteristics, solving the bandwidth-delay constraints with two-layer genetic algorithm, the cost data of the route set was obtained. The results show that the proposed algorithm can effectively find an optimal solution for multicast routing problem.