An Effective SIP Security Solution for Heterogeneous Mobile Networks

With the evolution and penetration of the IP-based core network and the mobile access networks, more and more legacy services are being transferred to the converged and unified IP-based platform. For realizing this transfer, SIP (Session Initiation Protocol) has been adopted by standards bodies for creating, modifying, and terminating multimedia sessions. SIP with application-level mobility support can replace MIP (Mobile IP) to provide a FMC (Fixed Mobile Convergence) solution. Taking the important role of SIP into account, it is critical to fully resolve the SIP security issues including service authentication, confidentiality, and integrity protection on both signaling and data transmission. IPSec (IP Security) and the combination of TLS (Transport Layer Security) and SRTP (Secure Real-time Transport Protocol) are two typical SIP security solutions that can protect 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 effective SIP security solution that realizes SIP security with seamless mobility support across heterogeneous mobile networks. We compare the proposal to existing approaches and show that it better satisfies the SIP security requirements in terms of security, mobility support, and performance.