Transmission apparatus with mechanism for reserving resources for recovery paths in label-switched network
A recovery-path request message control block generates, sends, and receives a recovery-path request message containing failure location information and recovery-path setup information. A label assignment message control block generates, sends, and receives a label assignment message. A setup label information generation block generates setup label information. A recovery-path label table management block constructs and manages a recovery-path label table. A failure detection block detects the location of a failure. A failure notification message transfer block transfers a failure notification message containing failure location information. A recovery-path establishment block establishes a recovery-path by comparing failure location information contained in a failure notification message and failure location information contained in a recovery-path label table and by selecting setup label information corresponding to matching failure location information.
1. 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.
2. The transmission apparatus according to claim 1 , wherein the recovery-path request message control block includes a share flag indicating whether a resource is shared in a recovery-path request message when a recovery-path is set up.
3. 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.
4. The transmission apparatus according to claim 3 , wherein the recovery-path request message control block includes a share flag indicating whether a resource is shared in a recovery-path request message when a recovery-path is set up.
5. 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.
6. The transmission apparatus according to claim 5 , wherein the recovery-path request message control block includes a share flag indicating whether a resource is shared in a recovery-path request message when a recovery-path is set up.
7. 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.
8. The failure circumvention method according to claim 7 , wherein a recovery-path request message includes a share flag indicating whether a resource is shared when a recovery-path is set up.
9. 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.
10. The failure circumvention method according to claim 9 , wherein a recovery-path request message includes a share flag indicating whether a resource is shared when a recovery-path is set up.
11. 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.
12. The failure circumvention method according to claim 11 , wherein a recovery-path request message includes a share flag indicating whether a resource is shared when a recovery-path is set up.