An IP converged system includes a VoIP ALG module and a policer module. The VoIP ALG module acquires dynamically changing RTP IP/port information of a packet by parsing a VoIP SIP message, and transmits the RTP IP/port information to the policer module. The policer module sets IP/port, which provides a real-time data service, by referring to the information from the VoIP ALG module, and discriminatively sets a packet processing condition for a non-real-time data service and a packet processing condition for the real-time data service. The VoIP ALG module and the policer module share RTP IP/port information, dynamically determined by the negotiation between VoIP gateways or VoIP terminals, in call setup/release, so that the policer can discriminately drop or mark VoIP packets by referring to the RTP IP/port information.