REDUNDANT PACKET EXCHANGE SYSTEM AND SYSTEM SWITCHING METHOD FOR REDUNDANT PACKET EXCHANGE SYSTEM

摘要

An auxiliary unit (52) receives the same packet as that which the operational unit (51) transfers from interface sections (521-1 to 521-n) after the operation of the operational unit (51) is lastly confirmed until the operation is next confirmed. A transfer section (522) processes the packets, and storage sections (525-1 to 525-n) hold them. The operation state of the operational unit (51) is monitored by means of an advertisement which the operational unit (51) transmits. When the advertisement is received, the packets held in the storage sections (525-1 to 525-n) are discarded. On the basis of the fact that any advertisement is not received for a predetermined time, it is judged that the operational unit (51) has stopped. Then, the packets held in the storage sections (525-1 to 525-n) are sent out, and the auxiliary unit (52) switches the processing so that the auxiliary unit (52) itself operates as an operational unit.