Reoptimization of Point-to-Multipoint Traffic Engineering Loosely Routed LSPs

For a Traffic Engineered (TE) point-to-multipoint (P2MP) Label Switched Path (LSP), it is preferable in some cases to re-evaluate and re-optimize the entire P2MP-TE LSP by re-signaling all its S2L sub- LSP(s). Existing mechanisms allow the path re-evaluation and the signaling of a the notification of preferred path exists for a single S2L sub-LSP only. This document defines RSVP-TE signaling extensions to allow an ingress Label Switching Router (LSR) of a P2MP-TE LSP to trigger the re-evaluation of the entire LSP tree containing one or more S2L sub- LSPs whose paths are loose (or abstract) hop expanded, and for a mid- point LSR to signal to the ingress LSR that a better tree exists for the entire P2MP-TE LSP.