VOIP SERVICE SYSTEM AND A METHOD FOR PROCESSING A CALL USING THE SAME, PARTICULARLY REGARDING TO EASILY EXPANDING A USER AGENT BY FUNCTIONS AND REPLACING MODULES OF THE USER AGENT

摘要

PURPOSE: A VoIP service system and a method for processing a call using the same are provided to easily expand a user agent by functions and replace modules of the user agent by designing the user agent in a plurality of modules by functions and providing an interface of each step in a detail function or library form and to provide various VoIP services by calling an API provided from the user agent regardless of an inferior protocol. CONSTITUTION: A transportation protocol(300) communicates with a user agent(200) for transmitting and receiving an SIP(Session Initiation Protocol) message. The user agent(200) provides an SIP protocol and an API(Application Programming Interface) to a VoIP(Voice over IP Gateway) application service(100) and generates an SIP message according to an API call of the VoIP application service(100) to provide the generated SIP message to the transportation protocol(300). The user agent(200) processes the SIP message received from the transportation protocol(300) and calls a call back function of the VoIP application service(100) according to the SIP message. The VoIP application service(100) has the call back function, requests a VoIP service through the API call of the user agent(200), and receives the VoIP service by using the call back function called by the user agent(200).