Patent ID: 9178798
Filing Date: 2015-11-03
Classification: H04L

Abstract:
1. A method comprising: establishing, with an upstream router using multicast extensions to Label Distribution Protocol (mLDP), a multipoint label switched path (LSP) between at least one root router and two or more leaf routers, the multipoint LSP including a direct link as a primary path between the upstream router and a downstream router; establishing, with the upstream router using a Label Distribution Protocol (LDP), a point-to-point (P2P) LSP to the downstream router as a backup path between the upstream router and the downstream router, wherein the P2P LSP avoids the direct link between the upstream router and the downstream router that is a protected link of the multipoint LSP; establishing, with the upstream router using the mLDP, a targeted adjacency session between the upstream router and the downstream router, wherein a targeted adjacency session label associated with the multipoint LSP is allocated for the targeted adjacency session by the downstream router; installing a primary next hop with an associated primary label for the primary path of the multipoint LSP into forwarding information of the upstream router, wherein the primary label includes the targeted adjacency session label associated with the multipoint LSP; installing an alternate next hop with an associated alternate label stack for the backup path of the P2P LSP into forwarding information of the upstream router, wherein the alternate label stack includes a P2P LSP label associated with the P2P LSP and the targeted adjacency session label associated with the multipoint LSP; forwarding multicast traffic from the upstream router toward the downstream router along the multipoint LSP according to the primary next hop with the primary label; and upon detecting a failure of the protected link of the multipoint LSP, tunneling the multicast traffic from the upstream router toward the downstream router along the P2P LSP according to the alternate next hop with the associated alternate label stack.