Access Security Solution Of IMS Network

Nowadays, Telecommunication Network is evolving to the IP based Next Generation Network which can provide all kinds of services. The IMS is based on SIP protocol and is access-agnostic and has standard interface to service platform, so it has been accepted as the core control platform by many organizations. All of these standard organizations are researching on the network organization of IMS based NGN.IMS is a SIP based All-IP architecture; because of the inherent limitation of IP protocol, the IMS network isn't secure at all. Additionally, the IMS support multi-access (such as WLAN/WiMax, fixed etc.), and the UE is more and more open and transfering to intelligent Endpoint, thus the security threaten of IMS may be more serious. The security of IMS network is very important, only having better network security solution and access security solution can assure the reliable IMS deployment, then the IMS can come to commercial.This paper is on this background, analysing the access security solution of IMS Network. Firstly, it introduces the environment of IMS origin, the IMS based NGN, the secure problem IMS may meet, IMS security architecture and secure mechanism. Then, it discusses the security solution for UMTS access and WLAN access. For UMTS access, it analyses the AKA authentication progress and the SA build procedure between the UE and P-CSCF. For WLAN access, it introduces 3GPP UMTS-WLAN security solution and bring forward an easy deployment security solution .At last, It introduces Early IMS and analyses the scenario of early IMS and give the related security solution for different scenarios.