A communication control method for controlling communication between a first node and a second node via a relay device, the method includes transmitting a control packet from the first node to the second node before transmitting a first packet which is a higher priority than another packet to be relayed, stopping a packet from being output from a packet storage device for the another packet by the relay device, for a period indicated by the control packet, the packet storage device being included in one of a plurality of output ports of the relay device from which the first packet is to be output, and transmitting the first packet from the first node to the second node or from the second node to the first node during the period.