A media data classification is provided. A Serving GPRS Supporting Node (SGSN) for indicating an IP Multimedia Subsystem (IMS) data flow in a mobile communication system includes a communication module for communicating with other nodes; and a media flow manager for communicating with the other nodes through the communication module, receiving a Packet Data Protocol (PDP) context activation message, and transmitting a PDP context generation message by including information indicative of IMS data when there is the information indicative of the IMS data.