Method and apparatus for establishing and modifying traffic path on basis of service data flow in mobile communication system

An apparatus for establishing a traffic path and transmitting the established traffic path in a mobile communication system, the apparatus comprising:

• a memory for storing at least one program;
• a transmitting and receiving unit for transmitting and receiving at least one signal;
• and
• a processor for executing the at least one program stored in the memory,
• wherein the processor receives an SM policy association establishment request message or an SM policy association modification request message on the basis of protocol data unit (PDU) session establishment, obtains policy-related information from a unified data repository (UDR) on the basis of an SM policy association establishment request or an SM policy association modification request, and performs a policy decision on the basis of whether a previously stored policy and charging control (PCC) rule related to the PDU session establishment exists in the policy-related information, and
• the policy decision comprises traffic routing for each service data flow (SDF), and transmits an SM policy association establishment response message or an SM policy association modification response message, which comprises policy decision information, to a session management function (SMF).