SIP mobility and IPv4/IPv6 dual-stack supports in 3G IP multimedia subsystem

Abstract

In the Universal Mobile Telecommunications System (UNITS), session initiation protocol (SIP) and IPv6 are the default protocols for IP multimedia core network subsystem (IMS). However, a user equipment (UE) may not be allowed to roam or hand off from UNITS to a private-lPv4 GPRS network. In this paper, we utilize SIP mobility and an automatic IPv6 tunneling mechanism, called Teredo, to support roaming/handoff of a UE between different networks. We have developed the first non-commercial Linux-based Teredo mechanism, and compared our solution with other Teredo implementations in the public domain. Our study indicates that our solution can reduce the tunneling overhead and transmission delay over two other implementations by 44-74%. Copyright (C) 2006 John Wiley & Sons, Ltd.