Abstract: A method and system to rout a Voice over Internet Protocol (VoIP) call based on a service class of a subscriber enables efficient utilization of bandwidth by providing service corresponding to the subscriber service class, while enabling use of a Virtual Private Network (VPN) which provides security to a VoIP service.

Abstract: An apparatus and method for performing dynamic security in an Internet Protocol (IP) system. The apparatus includes: a resource pool for storing information on resources related to IP services, and authentication information; and a security module for receiving a request to use resources for the IP services, requesting address translation according to the corresponding resource information stored in the resource pool, or resource reservation for the address translation or operation of a firewall, and requesting interruption of the resource use when the use of the corresponding resources is terminated.

Abstract: A method and system to rout a Voice over Internet Protocol (VoIP) call based on a service class of a subscriber enables efficient utilization of bandwidth by providing service corresponding to the subscriber service class, while enabling use of a Virtual Private Network (VPN) which provides security to a VoIP service.