PACKET SWITCHED NETWORK, FAULT CONTROL APPARATUS AND PACKET-SWITCHING DEVICE

PROBLEM TO BE SOLVED: To provide a packet switched network capable of selecting an optimal route for a packet according to the state of the network. SOLUTION: A fault-monitoring packet is transmitted/received between packet-switching devices which are in opposing positional relation in a specific network zone; the packet-switching device that serves as a destination node of the fault-monitoring packet, notifies a fault control apparatus of the receiving state of the fault-monitoring packet and the fault control apparatus determines a fault occurrence zone; a fault recovery zone and communication quality from the receiving state of the fault-monitoring packet, generates optimal network route information, as needed, and transmits a route change notification packet to the packet-switching device, where a routing table thereof has to be updated. COPYRIGHT: (C)2009,JPO&INPIT