Patent ID: 7787380

Claim:
A method comprising: establishing a first Resource Reservation Protocol with Traffic Engineering (RSVP-TE) Point to Multi-Point (P2MP) Label Switched Path (LSP) across a backbone domain between an upstream router and two or more downstream routers, wherein the upstream router is positioned between the downstream routers and a source of traffic for the first RSVP-TE P2MP LSP; receiving, with the upstream router, a Path message for a second RSVP-TE P2MP LSP established over two or more edge domains via the first RSVP-TE P2MP LSP within the backbone domain; sending a Path message from the upstream router to the downstream routers within the backbone domain to establish a P2MP LSP hierarchy with the first RSVP-TE P2MP LSP and the second RSVP-TE P2MP LSP, wherein the Path message sent by the upstream router to the downstream routers includes an upstream assigned label allocated by the upstream router for the second RSVP-TE P2MP LSP and a tunnel identifier that identifies the first RSVP-TE P2MP LSP to establish a P2MP LSP hierarchy; after establishing the first RSVP-TE P2MP LSP and the second RSVP-TE P2MP LSP as a P2MP LSP hierarchy, encapsulating a packet received on the second RSVP-TE P2MP LSP in the first RSVP-TE P2MP LSP using the upstream assigned label; and forwarding a single copy of the encapsulated packet from the upstream router to the downstream routers of the first RSVP-TE P2MP LSP within the backbone domain with the upstream assigned label.