In a communication system having multiple nodes communicably connected via a ring network, at least two of the nodes each includes: a packet distributor that receives an ordinary packet and an interrupt packet from another node and distributes the received packets; and an output switching unit that outputs the ordinary packet and the interrupt packet that are not addressed to the own node such that the interrupt packet is output more preferentially than the ordinary packet. When the output switching unit receives the interrupt packet while outputting the ordinary packet, the output switching unit outputs the interrupt packet by embedding it into the ordinary packet that is being output at a position between the header and trailer of the ordinary packet. When the ordinary packet transmitted from the other node contains an interrupt packet embedded therein, the packet distributor extracts the interrupt packet and distributes the extracted interrupt packet.