P2P网络的NAT穿越技术研究

P2P网络基于互联网，在网络电话、在线游戏、多媒体通信、即时消息、文件和工作空间共享等领域有重要的应用，这促进了健壮、可靠的网络地址转换（NAT）穿越技术的需求。讨论当前P2P网络中NAT穿越技术及面临的挑战；对检测NAT进行分类并讨论UDP和TCP穿越技术；分析中继、反向连接和打洞等方法；最后简单介绍测试平台的开发，用来评估NAT穿越技术，并且在P2P网构建时给出适合的配置。

The Research of NAT Traversal Techniques in Peer-to-Peer Networks

Peer to peer (P2P) networking has important applications in Internet telephony, online gaming, multimedia communication,instant messaging,file and workspace sharing which raises the need for robust and reliable NAT traversal techniques. This paper discusses current and developing techniques and challenges posed by NAT traversal in P2P networks. Initially Network Address Translation (NAT) detection is categorised and both UDP and TCP traversal techniques are discussed. Methodologies such as Relaying, Connection Reversal, and Hole Punching are then analysed. Finally the development of a testbed is described which can be used to evaluate NAT traversal techniques and to determine appropriate configurations in order to achieve P2P networking.