SECURITY SYSTEM AND SECURING METHOD OF CALL SIGNALING MESSAGES FOR SESSION INITIATION PROTOCOL BASED VOICE OVER THE INTERNET PROTOCOL SERVICE

摘要

A security system of a call signaling message for an SIP(Session Initiation Protocol)-based VoIP(Voice over Internet Protocol) service and a method thereof are provided to block messages which are not suitable for message grammar or include blocking information registered in a blocking list or are not proper for message session states, thereby preventing an attack on a call signaling message. A message suitability verification module(10) receives call signaling messages transmitted between a terminal(1) and a server(2), blocks call signaling messages which do not comply with preset types, and delivers not-blocked call signaling messages. A filtering module(20) receives the call signaling messages, blocks call signaling messages including blocking information registered in a prestored blocking list, and delivers not-blocked call signaling messages. A message state verification module(30) receives the call signaling messages, blocks call signaling messages which do not correspond to session states, and transmits not-blocked messages to the terminal or the server.