Abstract: This paper develops a live streaming service grid（LSSG） as an extensible overlay multicast middleware architecture for supporting live media applications in tele-cooperate environment over multiple domain.The LSSG service is provided by the service brokers nodes（SvB） which are strategically deployed by network service providers.This paper mainly presents a QoS-oriented inter-domain overlay multicast algorithm（QIOM），which is used to organize the SvB to build a QoS-aware multicast service tree.It is an overlay based the multicast connection solution for live media relay in different domains，which makes the inter-domains resource management turning to the dynamic cooperating service management.The simulation results show that the QIOM algorithms can effectively find and provide QoS-assured overlay services and balance the overlay traffic burden among the SvB.

Key words: Quality of Service（QoS）, live streaming, live media service grid, interdomain overlay multicast tree

摘要： 针对跨域远程协作中的实时流通信质量问题，构建了实时流服务网格（LSSG），这是一个可扩展的且面向用户QoS需求的覆盖组播通信中间件结构，LSSG服务由网络服务提供商策略部署的服务代理（SvB）提供。论文主要采用面向QoS的域间覆盖组播算法（QIOM）来组织SvB建立实时流组播服务树，根据用户服务质量请求提供跨自治系统的实时流组通信服务，将域间资源管理转变为流媒体应用的动态协同服务管理。仿真结果表明QIOM能有效地发现和提供QoS满意的覆盖服务及实现SvB间的覆盖流量负载平衡。

关键词: 服务质量, 实时流, 覆盖组播, 实时流服务网格, 域间覆盖组播树