Patent ID: 8441923

Claim:
A communication path providing method for providing a communication path in a ring network having a plurality of communication nodes, one of the plurality of communication nodes being specified as a master node that provides a blocking port and releases the blocking port when a fault occurs in the ring network, comprising: setting transfer information of data in each of the plurality of communication nodes by making the transfer information correspond to connection information for identifying a connection within the ring network to provide a first communication path; notifying the plurality of communication nodes of a position where a fault occurs when the fault occurs in the ring network; determining whether or not to update the transfer information in each of the communication nodes according to the position where the fault occurs; and updating the transfer information according to the position where the fault occurs in one or more of the plurality of communication nodes, and providing a second communication path having an originating node and a terminating node which are identical to the first communication path, wherein each of the plurality of communication nodes transfers input data by using the first or second communication path according to transfer information corresponding to connection information attached to the input data wherein: each of the plurality of communication nodes has a first port for connecting to an adjacent communication node on an upstream side in the ring network, and a second port for connecting to an adjacent communication node on a downstream side in the ring network; the connection information specifies an originating node and a terminating node of the ring network; transfer information set in a first communication node specified as the originating node includes an instruction to output data flowing into the ring network to the first port; transfer information set in a second communication node specified as the terminating node includes an instruction to guide data received via the second port to outside of the ring network; and when a fault occurs on the first communication path extending between the first communication node and the second communication node, the transfer information of the first communication node is updated to an instruction to output the data flowing into the ring network to the second port, and the transfer information of the second communication node is updated to an instruction to guide the data received via the first port flow to outside of the ring network.