Protection of a Bidirectional Label Switched Path

A packet switching device, comprising:

• one or more processing elements;
• memory;
• a plurality of interfaces, including a first interface configured to receive packets on a first ingress label switched path (LSP) of a first segment of a bidirectional LSP passing through the packet switching device, a second interface configured to send packets on a first egress LSP of the first segment of the bidirectional LSP towards an originating LSP packet switching device, and a third interface configured to send packets on a second egress LSP of a second segment of the bidirectional LSP towards a destination LSP packet switching device;
• and
• one or more packet switching mechanisms configured to packet switch packets among said interfaces according to forwarding information;
• wherein said one or more processing elements are configured to perform operations, including updating said forwarding information comprising to cause label switched packets received on the first ingress LSP to be sent over the second egress LSP, and subsequently to cause particular label switched packets received on the first ingress LSP to be sent over the first egress LSP in response to an error condition identified as affecting at least the second egress LSP of the bidirectional LSP.

A method, comprising:

• sending, by an originating label switched path (LSP) packet switching device, a particular label switched packet to a destination packet switching device over an egress LSP of a primary bidirectional LSP, wherein the primary bidirectional LSP is established between the originating packet switching device and the destination packet switching device;
• receiving, by the originating packet switching device on an ingress LSP of the primary bidirectional LSP, the particular label switched packet previously said sent over the egress LSP;
• and
• sending, by the originating packet switching device, the particular label switched packet to the destination packet switching device over a backup LSP.