The present disclosure provides a method whereby a mobility management entity (MME) in a cellular communication system transmits uplink data, the method comprising: receiving uplink data from a terminal; determining if the received uplink data is an Internet Protocol (IP) packet by examining the uplink data; transmitting the uplink data to a destination node via a packet data network (PDN) if the uplink data is an IP packet; and transmitting the uplink data to the destination node via a service capability exposure function (SCEF) if the uplink data is not an IP packet, wherein the uplink data comprises an indicator for indicating whether the uplink data is an IP packet.