Security of connecting SIP trunk via SBC on IMS network

In this paper, we have studied and described the security of SIP Trunk on IMS network (IP Multimedia Subsystem) via SBC (Session Border Controller), introduced a model by installing SBC to connect between IMS Network and IP-PBX in concept of SIP Trunk and present new method to increase performance of SIP Trunk by specified concurrent call, setting the caller discrimination to filter subscriber number that are not specified in the system cannot call via SIP Trunk (To prevent Hijacked subscriber illegally) and limit minimum and maximum digit of subscriber in the system to protect the security from inside and outside attacker that can effected the performance of network. Furthermore, we have set the experiment with the live network by installing the system follow by system model consists of PBX server connected to IMS network (IP Multimedia Subsystem) via SBC (SBC is installed between IMS network and IP PBX, using wireshark to monitor and analyze signaling flow of each equipment. Finally, the result from experiment are show the system model can secure and protect system from inside and outside attacker including prevent Hijacked subscriber illegally and can be used to increase the performance of SIP Trunk security in live network efficiently.