Label distribution protocol graceful restart on existing sessions
AssigneeCiena Corporation
InventorsSagar Sikri, Gaurav Agarwal, Pawan Sharma, Jayant Kumar Bhardwaj
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Abstract
Systems and methods include operating a label distribution protocol (LDP) session with a peer node in a network; responsive to a change in graceful restart of the LDP session, sending a notification message to the peer node with a graceful restart capability change indication; responsive to receiving a second notification message from the peer node with graceful restart capability change indication, updating the graceful restart capability for the LDP session; and, responsive to failing to receive the second notification message, leaving the graceful restart capability as it was prior to the change.
Claims20
A node in a network comprising:
- one or more modules and a plurality of ports;
- and
- circuitry configured to
- operate a label distribution protocol (LDP) session with a peer node in a network;
- responsive to a change in graceful restart of the LDP session, send a notification message to the peer node with a graceful restart capability change indication;
- responsive to receiving a second notification message from the peer node with graceful restart capability change indication, update the graceful restart capability for the LDP session, wherein the notification message and second notification messages each include a fault tolerant (FT) type-length-value (TLV) that signals a runtime change in graceful restart capability and a status TLV carrying a status code, distinct from existing LDP status codes, to indicate that capability change, wherein the runtime change occurs during the LDP session after session establishment without tearing down the LDP session, and wherein the ET TLV includes a FT flags field comprising a graceful restart enable/disable bit that indicates whether graceful restart is enabled or disabled for the LDP session;
- and
- responsive to failing to receive the second notification message, leave the graceful restart capability as it was prior to the change.
A method comprising steps of:
- operating a label distribution protocol (LDP) session with a peer node in a network;
- responsive to a change in graceful restart of the LDP session, sending a notification message to the peer node with a graceful restart capability change indication;
- responsive to receiving a second notification message from the peer node with graceful restart capability change indication, update the graceful restart capability for the LDP session, wherein the notification message and second notification messages each include a fault tolerant (FT) type-length-value (TLV) that signals a runtime change in graceful restart capability and a status TLV carrying a status code, distinct from existing LDP status codes, to indicate that capability change, wherein the runtime change occurs during the LDP session after session establishment without tearing down the LDP session, and wherein the FTV TLV includes a FT flags field comprising a graceful restart enable/disable bit that indicates whether graceful restart is enabled or disabled for the LDP session;
- and
- responsive to failing to receive the second notification message, leaving the graceful restart capability as it was prior to the change.
A non-transitory computer-readable medium comprising instructions that, when executed, cause a node in a network to perform steps of:
- operating a label distribution protocol (LDP) session with a peer node in a network;
- responsive to a change in graceful restart of the LDP session, sending a notification message to the peer node with a graceful restart capability change indication;
- responsive to receiving a second notification message from the peer node with graceful restart capability change indication, update the graceful restart capability for the LDP session, wherein the notification message and second notification messages each include a fault tolerant (FT) type-length-value (TLV) that signals a runtime change in graceful restart capability and a status TLV carrying a status code, distinct from existing LDP status codes, to indicate that capability change, wherein the runtime change occurs during the LDP session after session establishment without tearing down the LDP session, and wherein the FTV TLV includes an FT flags field comprising a graceful restart enable/disable bit that indicates whether graceful restart is enabled or disabled for the LDP session;
- and
- responsive to failing to receive the second notification message, leaving the graceful restart capability as it was prior to the change.
Dependencies are inferred from the claim text.