P2P网络中利用UDP穿越NAT的研究

Research on Using UDP to Traverse NAT in Peer-to-Peer Networks

近年来,P2P技术所蕴涵的巨大创造力和应用前景正在逐步地被人们所认可,美国著名的《财富》杂志把P2P技术誉为将改变Internet未来的四大新技术之一。但是,为缓解IPv4地址紧缺的问题,互联网上部署了大量的NAT设备,它们的存在对P2P技术的实施造成了一定的阻碍。本文分析了几种主流NAT的工作方式,指出了NAT对P2P网络的影响,给出了一种使用UDP进行NAT穿越的方法。使用该方法可以让位于不同私网内的计算机进行直连通信,从而为P2P技术的实施提供了有益参考。

In recent years, P2P technology＇s the enormous creativity and application prospects are gradually being recognized by people. Well-known U.S. ＂Fortune＂ magazine describe P2P technology is one of the four new technologies that will change the future Of Internet. However, there are a large number of NAT devices were deployed on Internet in order to alleviate the shortage of IPv4 addresses, hindering the implementation of P2P technology. In this paper, the function of several mainstream NAT is analyzed, the negative ：impact on P2P networks caused by NAT is pointed, And a method of using UDP to traverse NAT is presented. This method allows computers in different private networks communicating directly, thereby, a useful reference for the implementation of P2P technology is provided.