An Efficient NAT Traversal for SIP and Its Associated Media sessions

Abstract

Session Initiation Protocol (SIP) standardized by IETF provides a way to establish the sessions between Internet telephony devices, but this protocol can’t work with Network Address Translator (NAT). Therefore how to make SIP NATfriendly becomes a worthy topic. This paper proposes an efficient approach TAB (Triggering Address Bindings on NAT), which helps SIP devices establish the shortest paths for the media sessions without modifying the existing NAT products. The approach is validated, and the results show that the traffic delay time between devices with TAB is reduced substantially than that with other solutions.