An Innovative SIP Security Mechanism with Seamless Mobility Support

With the evolution and proliferation of the All-IP core network and the mobile access network, more and more legacy services are being transferred to the converged and unified IP-based platform. For this transfer, SIP (Session Initial Protocol) has been adopted by IETF, ETSI, and 3GPP for creating, modifying, and terminating multimedia sessions. SIP with application-level mobility support can replace MIP (mobile IP) since it provides a FMC (fixed mobile convergence) solution. Taking the important role of SIP into consideration, it is critical to fully resolve the security issues including service authentication, confidentiality, and integrity protection on both SIP signaling and data transmission. IPSec (IP security) and the combination of TLS (transport layer security) and SRTP (secure real-time transport protocol) are two representative SIP security solutions that can protect SIP signaling and data transmission from various security attacks. However, these security solutions don´t consider the issue of mobility support during the handover of mobile nodes among different access networks. This paper, therefore, proposes an innovative SIP security mechanism that realizes SIP security with seamless mobility support in heterogeneous network environments. We compare the proposal to existing approaches and show that it better satisfies the SIP security requirements in terms of security strength, mobility support, and performance.