Patent ID: 8339942

Claim:
A machine-implemented method performed within a network element to establish a HELLO session with a remote node that is not immediately adjacent to the network element to determine, based on HELLO messages exchanged during the HELLO session, whether the remote node restarts, in order to preserve and recover state information of one or more protected label switched paths (LSPs) between the network element and the remote node, for the purpose of performing a restart procedure within the network element in view of restarting of the remote node, the method comprising the steps of: establishing the HELLO session with the remote node, including exchanging HELLO messages with the remote node, wherein each HELLO message includes a time-to-live (TTL) value greater than one if the HELLO message is to be routed using an Internet protocol (IP) forwarding protocol, wherein each HELLO message includes a TTL value of one if the HELLO message is to be forwarded via a tunnel established between the local and remote nodes; in response to at least one of a link failure and a node failure of the protected LSP, switching network traffic onto a protection path according to a fast re-reroute (FRR) scheme; and in response to a restart of the remote node, based on the HELLO messages exchanged during the HELLO session, performing the restart procedure according to a resource reservation protocol (RSVP) traffic engineering (TE) graceful restart (RSVP-TE GR) mechanism for preservation and recovery of LSP state information of the protected LSPs.