Patent ID: 8773978

Claim:
A network comprising: a first edge node; a second edge node; a third edge node that backs up either the first edge node or the second edge node; and an internal node coupled to the first edge node, the second edge node, and the third edge node, wherein a primary point-to-multipoint (P2MP) label switched path (LSP) extends across the network from the first edge node, through the internal node, and to the second edge node, wherein a backup LSP sub-tree extends only between the third edge node and the internal node, wherein the internal node is a next-hop node of the first edge node on the primary P2MP LSP, and wherein a packet cannot be delivered across the backup LSP sub-tree to the second edge node without switching from an LSP sub-tree label for the backup LSP sub-tree to a P2MP LSP label for the primary P2MP LSP at the internal node.