Point of Local Repair

When FRR is configured all the routers along the path assumes the role of the PLR

The label used by the PLR when there is a failure ie for the detour path depends upon the type of FRR which is being used. In the case of one to one the label used for the detour path is the label which is being assigned by the immediate downstream router on the detour path.

In the case of facility backup the data from the protected LSP is tunneled across a bypass tunnel, hence the outer label is the label which is assigned by the immediate downstream router of the detour path the PLR also has to know the label which is being expected by the Merge point, the record label option makes this possible for the RRO. Hence the PLR adds two labels one which is being received from the immediate downstream router of the detour path, the second label is the label which the Merge point expects.

Two messages are sent by PLR towards the HE router notifying the failure

Path Error message:- RSVP notify error and the value is tunnel locally repaired

It also sends the FRR in use flag set in the RRO object of the RESV message.