The user valence of VoIP services with SIP protocol is increasing rapidly because of cheap communication cost and its conveniency. But attacker can easily modify the packet contents of SIP protocol as SIP header is transmitted by using UDP methods in text form. The reason is that SIP protocols does not provide an authentication function on the transmission session. Therefore, existing SIP protocol is very weak on SIP Packet Flooding attack etc. In order to solve like this kinds of SIP vulnerabilities, we used SIP status codes under the monitoring module for detecting SIP Flooding attacks and additionally proposed an advanced protocol where the authentication and security function is strengthened about SIP packet. We managed SIP session spontaneously in order to strengthen security with SIP authentication function and to solve the vulnerability of SIP protocol. The proposed mechanism can securely send SIP packet to solves the security vulnerability with minimum traffic transmission. Also service delay in SIP proxy servers will be minimized to solve the overload problem on SIP proxy server.