基于STUNT的SymmetricNAT穿越

The NAT Traversal Based on STUNT

基于TCP的NAT穿越技术-STUNT能穿越大多数类型的NAT,解决了NAT后对等点之间TCP通信不可达的问题,使对等点之间通信得以实现。但由于SymmetricNAT的映射规则不同,使得STUNT穿越不可行。本文在STUNT的基础上,提出一个可行SymmetricNAT穿越方案,利用端口预测技术来预测通信端口地址,复用TCP的连接序号来伪造一个TCP连接,网域的设计解决了不支持环回地址的NAT通信问题。通过分析和实验测试,验证了本方案能很好地达到设计要求。

The NAT traversal technology-STUNT based on TCP can pass through most types of the NAT,which solves the problem of the inaccessible TCP communications between peers after operating NAT,and makes the communications between peers possible. This paper presents afeasible solution through SymmetricNAT based on the STUNT. It uses the port prediction techniques to predict the communication port address,and forges a TCP connection by reusing the TCP connection numbers. Also the design of the domain settles the problem that NAT communications cannot support loopback address. Finally through analysis and experiments,the solution is verified to well meet the design requirements.