Point of local Repair (PLR) & Merge Point

The router providing the failure protection is called the point of local repair (PLR).

During the failure the PLR sends the path err message to the HE router. The PLR should also notify the HE router that the FRR is in use.

When a PLR reroutes the traffic across the failure it sets the local protection in use flag in the RESV message which is sent back to the HE router.

The merge point (MP) is the router where the rerouted traffic merges back to the original path.

Every router along the LSP path should consider itself as a potential PLR except the Tail end router, also every router should consider itself as the merge point except the HE router.