摘要： 在Overlay组播路由中既需要考虑确保数据流能获得它所需要的服务，还需要确保不同的服务按照合适的次序到达，这是一个新的值得研究的问题，称之为服务组合问题。该文研究了Overlay组播网络中的服务组合问题，建立了相应的优化模型，设计了求解该模型的启发式算法。大量的仿真表明了该模型和算法的有效性。

关键词: Overlay组播网络, 服务组合, 扩展最短路径算法

Abstract: This paper investigates the service combination problem in overlay multicasting network by taking both the service assuring and order of service into consideration. It presents an optimization model and designs a heuristic algorithm on the service combination problem. Large amount of simulations suggest the model and the algorithm are practical and effective.

Key words: Overlay multicast network, Service composition, Extend short path algorithm