The invention is directed toward techniques for Multi-Protocol Label
Switching (MPLS) upstream label assignment for the Resource Reservation
Protocol with Traffic Engineering (RSVP-TE). The techniques include
extensions to the RSVP-TE that enable distribution of upstream assigned
labels in Path messages from an upstream router to two or more downstream
routers of tunnel established over a network. The tunnel may comprise a
RSVP-TE P2MP Label Switched Path (LSP) or an Internet Protocol (IP)
multicast tunnel. The techniques also include extensions to the RSVP-TE
that enable a router to advertise upstream label assignment capability to
neighboring routers in the network. The MPLS upstream label assignment
using RSVP-TE described herein enables a branch router to avoid traffic
replication on a Local Area Network (LAN) for RSVP-TE P2MP LSPs.