Patent ID: 8462635

Claim:
A method comprising: establishing a first Point to Multi-Point (P2MP) Label Switched Path (LSP) across a network 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 P2MP LSP; receiving, with the upstream router, a message for a second P2MP LSP established over two or more edge domains via the first P2MP LSP within the network; sending a message from the upstream router to the downstream routers within the network to establish a P2MP LSP hierarchy with the first P2MP LSP and the second P2MP LSP, wherein the message sent by the upstream router to the downstream routers includes an upstream assigned label allocated by the upstream router for the second P2MP LSP and a tunnel identifier that identifies the first P2MP LSP to establish a P2MP LSP hierarchy; after establishing the first P2MP LSP and the second P2MP LSP as a P2MP LSP hierarchy, encapsulating a packet received on the second P2MP LSP in the first 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 P2MP LSP within the network with the upstream assigned label.