【摘要】 由于Internet采用尽力而为的服务,VoIP系统存在QoS问题。为改善QoS,多数系统采用"应用层路由"方案,该方案关键是如何查找拓扑最优中继节点。结合P2P技术,提出一种拓扑感知的P2P中继查找机制。首先构建一个Cluster Overlay网络来模拟真实的Internet拓扑;在Cluster Overlay网络上设计一种拓扑感知的中继查找算法;最后在SIP终端中实现这种方案。在NS2平台上对Cluster Overlay网络和中继查找机制进行了仿真实验。结果表明:Cluster Overlay网络和真实的Internet拓扑相似度很高,中继查找算法能查找到最优中继结点,从而改进了路径质量。更多还原

【Abstract】 Because of the best-effort service of the Internet,the VoIP system has QoS problem.In order to improve QoS,most systems use application-layer routing mechanism.One of the key issues of the mechanism is how to search for relay node.Combining the P2P technology,this paper proposes a topology-aware based P2P relay search mechanism.First,in order to simulate the real Internet topology,a Cluster Overlay network was built.In the Cluster Overlay network,a topology-aware relay search algorithm was designed.Finally,this program was achieved in the SIP terminal.A simulation on the Cluster Overlay network and relay search mechanism was carried out on the NS2 platform.The results show that the similarity between the Cluster Overlay network and the real Internet topology is very high.The relay search algorithm can find the optimal relay node,thus to improve the quality of the path.更多还原