RELAY APPARATUS WHICH RELAYS MESSAGES, AND PROGRAM OF SAME

摘要

A relay apparatus provided with: an I/O port (110a) provided with a reception unit which receives a first synchronization message from a first communication apparatus, said first synchronization message addressed to a second communication apparatus and including the time of transmission; a calculation unit (103) which calculates a holding time until transmission of the first synchronization message to the second communication apparatus; a transmission control unit inside the I/O port (110a) which transmits the first synchronization message to the second communication apparatus after the holding time has passed since receipt of the first synchronization message; I/O ports (110b to d) which are each provided with a reception unit which receives a second synchronization message from the second communication apparatus, said second synchronization message transmitted addressed to the first communication apparatus in response to the first synchronization message and including the time of transmission; and a transmission control unit inside each of the I/O ports (110b to d) which transmits the second synchronization message to the first communication apparatus after the holding time which had been calculated with respect to the corresponding first synchronization message has passed since receipt of the second synchronization message.