Cisco Systems Cisco Systems Cisco Systems Defense Information Systems Agency NTT Communications Corporation 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 Source-to-Leaf (S2L) sub-LSP(s). Existing mechanisms, a mechanism for an ingress Label Switched Router (LSR) to trigger a new path re- evaluation request and a mechanism for a mid-point LSR to notify an availability of a preferred path, operate on an individual or a sub- group of S2L sub-LSP(s) basis only. This document defines RSVP-TE signaling extensions to allow an ingress node of a P2MP-TE LSP to request 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 notify to the ingress node that a preferable tree exists for the entire P2MP-TE LSP. This document also defines markers to indicate beginning and end of a S2L sub-LSP descriptor list when RSVP message needs to be fragmented due to large number of S2L sub-LSPs when performing re-optimization.