FRR LSP switch to backup path on bypass LSP

Facility-protected FRR LSP uses a bypass LSP to carry its traffic whenever there is a failure in its protected path. Multiple events can lead to switching traffic from a protected LSP to a backup path. Some primary reasons for switching the protected LSP traffic to its corresponding backup paths over a bypass LSP include a protected or excluded interface going down, or a NHOP node going down.

At every PLR node of a facility-protected LSP, whenever a backup path is associated with a bypass LSP, the following actions take place:

The facility-protected FRR LSP initiates the FRR switch based on the FRR switch trigger event. Upon FRR protection switch trigger, the following actions take place:

At any time, it is possible that there can be Active, switched, or up, as well as non-switched backup paths on the bypass LSP.