Abstract: Due to the mismatch between P2P overlay network and physical network,the routing latency is inefficient.This paper shows the idea that a topology-aware routing approach which uses groups and caches---GcChord（Group Cache based Chord）.Experiment results demonstrate that GcChord improves the routing performance effectively,especially when nodes are apt to send some query more than others,both of the average logical hops and physical hop are improved observably.

Key words: pear-to-pear network, group, topology-aware, cache, chord

摘要： 在基于DHT技术的对等网络中,一个重要的研究内容是减少逻辑网络和物理网络不匹配所带来的寻路时延过长的问题。文章提出一种利用组来匹配物理网络,利用超级节点缓存查询和地址信息,并且在普通节点收到查询请求时缓存查询源节点地址信息的路由算法GcChord（Group Cache based Chord）。仿真结果表明,GcChord的路由性能优于Chord系统,并且节点重复（有一定倾向）查询越多,其平均物理、逻辑跳数越少。

关键词: 对等网络, 组, 拓扑匹配, 缓存, Chord系统