Patent ID: 8463120

Claim:
In an Automatically Switched Optical Network (ASON), in order to efficiently establish a restoration path to restore transmission of a service when a failure occurs in a working path for the service, a method for establishing a restoration path comprising: receiving, by an intermediate node, from a node B of the working path for the service, a second restoration path setup request comprising a second Label Switch Path Identification (LSP ID) and a bidirectional restoration flag bit indicating that a node A and the node B of the working path both initiate a signaling message to establish the restoration path for the working path; determining, by the intermediate node, that no connection has been established based on the restoration path setup request from the node B of the working path; based upon the determination, establishing, by the intermediate node, a second connection according to the restoration path setup request received from the node B of the working path; receiving, by the intermediate node, from the node A of the working path for the service, a first restoration path setup request comprising a first LSP ID indicating a same restoration path as the second LSP ID and the bidirectional restoration flag bit indicating that the node A and the node B of the working path both initiate the signaling message to establish the restoration path for the working path; determining, by the intermediate node, that the second restoration path setup request from the node B of the working path has been received; determining, by the intermediate node, that a second connection has been established based on the restoration path setup request from the node B of the working path; determining, by the intermediate node, that the first restoration path setup request from the node A of the working path is provided with a decision right; based upon the determinations, disconnecting, by the intermediate node, the connection which is established according to the second restoration path setup request received from the node B of the working path; establishing, by the intermediate node, a first connection according to the first restoration path setup request received from the node A of the working path; and sending, by the intermediate node, a setup request acknowledge message to the node A to notify the node A that the first connection has been established.