PURPOSE: To eliminate the setting of paths different from each other in the up and down directions by handling a virtual path as a bi-directional transmission line and setting only the node on one side of the faulty part of P faulty path as the transmitter of a message at the time of generating a fault to reduce the generation volume of the message.
CONSTITUTION: A communication network is composed of seven nodes A to E, X, Y and AB to DE, CX, CY, which connect them. Paths 1 to 4 as the bi- directional transmission lines are set. Information of one frame is composed of a section overhead 10, bus information 12-1 to 12-n and the areas of bus overheads 14-1 to 14-n which are fitted to respective pieces of information 12-1 to 12-n. For example, when a fault is generated only at a transmission line from a node 3 toward a node 1 in a link L1, the node 1 can detect it. But, as the node 1 is a chooser concerning a path P1 housed in the link L1, it can not send the message. In order to avoid this situation, when a node on a user side detects the fault, it can send the message reporting the generation of the fault in the direction.
ISEDA HIDEHIRA
SATO YASUYUKI
NAKAJO TAKAFUMI
