A method for transmitting and receiving a packet performed by a first network node in a wireless communication system according to the present disclosure includes receiving a first message in relation to a connection configuration of a specific flow from a user equipment (UE); receiving a second message in relation to a response to the first message from a second network node (e.g., MME/GW); checking whether the first flow ID and the second flow ID are identical; transmitting a UL grant to the UE by considering a processing time of the UE; and receiving a third message from the UE through the UL grant.