Provided is a technique for eliminating buffer and transfer of a packet which is not required for an MN in a handover mechanism in which a packet to be sent to the MN performing handover is buffered and the buffered packet is supplied to the MN after the handover. Before handover, a mobile terminal (MN) notifies an access router (nAR) to be newly connected after the handover of information (buff_time/flow) indicating a correspondence between a flow label of a packet concerned with packet communication and a buffer time based on a delay allowance time of an application using the packet having the flow label. The nAR buffers the packet while the MN performs the handover. When performing packet transfer to the MN connected after the handover, the nAR does not transfer, to MN, the packet stored for a predetermined buffer time or more among the packets stored in the buffer.