Resource reservation protocol with traffic engineering point to multi-point label switched path hierarchy

A tangible computer-readable medium comprising instructions that cause a programmable processor to:

• establish 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;
• receive, 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;
• send 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.

An upstream router within a backbone domain comprising:

• a signaling protocol to establish a first Resource Reservation Protocol with Traffic Engineering (RSVP-TE) Point to Multi-Point (P2MP) Label Switched Path (LSP) across the backbone domain between the 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;
• a control unit having a processor that receives 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;
• and
• an upstream label module of the signaling protocol that allocates an upstream assigned label for the second RSVP TE P2MP LSP and sends a Path message to the downstream routers within the backbone domain that includes the upstream assigned label allocated 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,
• wherein the upstream router encapsulates a packet received on the second RSVP-TE P2MP LSP in the first RSVP-TE P2MP LSP using the upstream assigned label, and forwards 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.

A system comprising:

• a backbone domain that includes an upstream router and two or more downstream routers, wherein the upstream router establishes a first Resource Reservation Protocol with Traffic Engineering (RSVP-TE) Point to Multi-Point (P2MP) Label Switched Path (LSP) across the backbone domain between the upstream router and the downstream routers;
• and
• an edge domain that includes an upstream router that establishes a second RSVP-TE P2MP LSP over two or more edge domains via the first RSVP-TE P2MP LSP within the backbone domain,
• wherein the upstream router within the backbone domain is positioned between the downstream routers of the backbone domain and the upstream router of the edge domain,
• wherein the upstream router within the backbone domain sends a Path message to the downstream routers within the backbone domain that includes an upstream assigned label allocated by the upstream router within the backbone domain 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, and
• wherein the upstream router encapsulates a packet received on the second RSVP-TE P2MP LSP in the first RSVP-TE P2MP LSP using the upstream assigned label, and forwards 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.