The Research of Network Address Translation Traverse in Soft Switch System

VoIP technology is becoming more and more popular. Because of the pinch of IP addresses in IPv4 environment, NAT is a popular way to solve this problem. But one of the is how to traverse NAT. This paper has made an exposition of the basic concept of NAT, listed some core problems that NAT has to face in VoIP technology, introduced two mainstream traverse plans: ALG and STUN and analyzed their principle and network topology, and their shortcomings. On the basis of ALG and STUN, the authors have worked out a revolutionary plan: SBC+MP, analyzed in detail its principle, network topology, its work flow and advantages compared with ALG and STUN. In the end, we have made a conclusion about NA T technology.