Transmission apparatus with mechanism for reserving resources for recovery paths in label-switched network

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 maintenance priority if a recovery-path must be established in a link of an already-established recovery-path and if the recovery-path label table contains a plurality of information items matching the failure location information contained in the failure notification message.

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 setup label information corresponding to any matching failure location information;
• wherein the setup label information generation block included in a node where a working path and a recovery-path meet generates setup label information by associating the output interface identifier of the working path and the output label with the input interface identifier of the recovery-path and the input label or by associating the input interface identifier of the working path and the input label with the output interface identifier of the recovery-path and the output label.

A failure circumvention method for circumventing a failure on a generalized multi-protocol label switching (GMPLS) network, the failure circumvention method comprising:

• generating, in a node in the network, failure location information specifying which node or link on a working path of the network is to be protected from failure;
• sending and receiving, before any failure occurs on the working path of the network, a recovery-path request message containing failure location information and recovery-path setup information used to set up a recovery-path for failure recovery, between nodes;
• sending and receiving a label assignment message as a response to the recovery-path request message, between nodes;
• generating 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;
• constructing and managing a recovery-path label table containing failure location information and setup label information;
• detecting the location of a failure that has occurred using a node close to the failure;
• transferring a failure notification message containing the failure location information of the failure, between nodes;
• and
• establishing 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.

A failure circumvention method for circumventing a failure on a generalized multi-protocol label switching (GMPLS) network, the failure circumvention method comprising:

• generating, in a node in the network, failure location information specifying which node or link on a working path of the network is to be protected from failure;
• sending and receiving, before any failure occurs on the working path of the network, a recovery-path request message containing the failure location information and recovery-path setup information used to set up a recovery-path for failure recovery, between nodes;
• sending and receiving a label assignment message as a response to the recovery-path request message, between nodes;
• generating 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;
• constructing and managing a recovery-path label table containing failure location information and setup label information;
• detecting the location of a failure that has occurred using a node close to the failure;
• transferring a failure notification message containing the failure location information of the failure, between nodes;
• and
• establishing 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 maintenance priority, if a recovery-path must be established in a link of an already-established recovery-path and if the recovery-path label table contains a plurality of information items matching the failure location information contained in the failure notification message.

A failure circumvention method for circumventing a failure on a generalized multi-protocol label switching (GMPLS) network, the failure circumvention method comprising:

• generating, in a node in the network, failure location information specifying which node or link on a working path of the network is to be protected from failure;
• sending and receiving, before any failure occurs on the working path of the network, a recovery-path request message containing the failure location information and recovery-path setup information used to set up a recovery-path for failure recovery, between nodes;
• sending and receiving a label assignment message as a response to the recovery-path request message, between nodes;
• generating 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;
• constructing and managing a recovery-path label table containing failure location information and setup label information;
• detecting the location of a failure that has occurred using a node close to the failure;
• transferring a failure notification message containing the failure location information of the failure, between nodes;
• establishing 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 setup label information corresponding to any matching failure location information using a node receiving the failure notification message;
• and
• generating, in a node where a working path and a recovery-path meet, setup label information by associating the output interface identifier of the working path and the output label with the input interface identifier of the recovery-path and the input label or by associating the input interface identifier of the working path and the input label with the output interface identifier of the recovery-path and the output label.