Providing End-to-End Connectivity to SIP User Agents Behind NATs

— The widespread diffusion of private networks in SOHO scenarios is fostering an increased deployment of Network Address Translators (NATs). The presence of NATs seriously limits end-to-end connectivity and prevents protocols like the Session Initiation Protocol (SIP) from working properly. This document shows how the Address List Extension (ALEX), which was originally developed to provide dual-stack and multi-homing support to SIP, can be used, with minor modifications, to ensure end-to-end connectivity for both media and signaling flows, without relying on intermediate relay nodes whenever it is possible.

• Type: Conference
• Year: 2008
• Where: ICC
• Authors: Mario Baldi, Luca De Marco, Fulvio Risso, Livio Torrero
• Keywords: Communications, End-to-end Connectivity, ICC 2008, Network Address Translators, Session Initiation Protocol