Patent ID: 7680029

Claim:
A transmission apparatus for performing signal transmission based on label switching while performing failure circumvention control, the transmission apparatus comprising: a label distribution control block including: a recovery-path request message control block to generate, send, and receive, before any failure occurs on a working path of a network, a recovery-path request message containing failure location information specifying which node or link on the working path is to be protected from failure and recovery-path setup information for setting up a recovery-path for failure recovery; a label assignment message control block a label assignment message as a response to the recovery-path request message; and a setup label information generation block to generate setup label information for label switching, in accordance with the recovery-path request message and the label assignment message, the setup label information containing: input information including an input interface identifier indicating a path to which data is input, and an input label for the input data, output information including an output interface identifier indicating a path from which data should be output, and an output label for the output data, establishment priority indicating establishment precedence given to a plurality of recovery-paths, and maintenance priority indicating maintenance precedence given to a plurality of recovery-paths; a recovery-path label table management block to construct and manage a recovery-path label table containing failure location information and setup label information; a failure notification block including: a failure detection block to detect a location of a failure that has occurred; and a failure notification message transfer block to transfer a failure notification message containing the failure location information of the failure; and a recovery-path establishment block to establish a recovery-path by comparing the failure location information contained in the failure notification message and the failure location information contained in the recovery-path label table and by selecting a setup label information item having the highest establishment priority if a plurality of recovery-paths must be simultaneously established in a single link and if the recovery-path label table contains a plurality of information items matching the failure location information contained in the failure notification message.