Patent ID: 7936780

Claim:
A method comprising: receiving a label mapping message at an ingress router within a first routing domain of a network for establishing an inter-routing domain label switched path (LSP), wherein the label mapping message identifies within a first portion of the label mapping message a first label to be used for forwarding network traffic to an intermediate router of the LSP, and identifies within a second portion of the label mapping message a second label to be used for forwarding network traffic to an egress router of the LSP within a second routing domain of the network; parsing the first portion and the second portion of the label mapping message to identify the first label and the second label; installing first forwarding state at the ingress router identifying the first label to be used for forwarding network traffic to the intermediate router; and installing second forwarding state at the ingress router identifying a two-label stack to be used for forwarding network traffic on the inter-routing domain LSP to the egress router, the two-label stack comprising the first label as an outer label and the second label as an inner label.