The purpose of the present invention is to provide a method and a device for efficiently supporting multi-link transmission regardless of the type of RAT and the types of protocols. The present invention provides a method for aggregating links in an IP layer, and a method by which a multi-packet gateway transmits a packet comprises: confirming information on a link available for a terminal; scheduling a received data packet on the basis of the information on the available link; and transmitting the data packet, wherein the data packet is distributed so as to be transmitted by using the available link.