P2MP - Re-Merge with single-abr

In a P2MP MPLS LSP network, the term re-merge refers to the case of an ingress (headend) or transit node (re-merge node) that creates a re-merge branch intersecting the P2MP LSP at another node down the tree. This may occur due to events such as an error in path calculation, an error in manual configuration, or network topology changes during the establishment of the P2MP LSP. In case P2MP LSP re-merge is needed, the re-merge node initiates the pruning of the re-merge sub-LSPs through signaling. When single-abr is enabled, it reduces the re-merge condition beyond the interarea, or interdomain, or inter-AS RSVP P2MP LSPs.