1. 3GPP. 3rd Generation Partnership Project, Technical Specification Group Services and Systems Aspects, IP Multimedia Subsystem, Stage 2. Technical Specification 3G TS 23.228 version 8.3.0 (2007-12), 2007.
2. IETF. SIP: Session Initiation Protocol. IETF RFC 3261, June 2002.
3. IETF. RTP: a transport protocol for real-time applications. IETF RFC 3550, July 2003.
4. An IPv4-IPv6 translation mechanism for SIP overlay network in UMTS All-IP environment;Chen;IEEE Journal on Selected Areas in Communications,2005
5. IETF. Network Address Translation-Protocol Translation (NAT-PT). IETF RFC 2766, February 2000.