Abstract: The traditional initiative monitoring model cannot monitor P2P specific information.Initiative monitoring model to P2P specific information has been raised.Taking P2P specific information as the center，each module of this model monitors the P2P specific information transmission network，gets the peer list and peer status information related to P2P specific information，then applies Peer Exchange（PEX） extend message to initiative measurement model，which can not only gets the connection among the peers，but also improves the initiative monitoring efficiency.Finally，aiming at introducing of PEX extend message，each performance of the model is analyzed.As the test indicates，by introducing PEX extend message technique to initiative monitoring model，it can dramatically improve the efficiency and speed of obtaining the peer list，which can increase the overlay rate of gotten peers.

Key words: P2P specific information, initiative monitoring model, peer exchange technique, virtual client, audience information

摘要： 针对传统的主动监测模型不能对P2P特定信息进行监测的问题，提出了一种面向P2P特定信息的主动监测模型。该模型的各个模块都以P2P特定信息为中心，对P2P特定信息传播网络进行监测，收集与P2P特定信息相关的节点列表及节点状态信息;创新性地将Peer Exchange（PEX）扩展消息用于主动测量模型，不但可以得到节点之间的连接关系，而且提高了主动监测效率。针对PEX扩展消息的引入，分析模型的各项性能指标。实验结果表明，在主动监测模型中引入PEX扩展消息技术，能够大幅度提高节点列表获取的效率和速度，并能够增加获取节点的覆盖率。

关键词: P2P特定信息, 主动监测模型, 节点交换技术, 仿真客户端, 受众信息