Automatic protection switching using link-level redundancy supporting multi-protocol label switching
View Patent ↗A computer network has a plurality of routers that deliver data packets to the network via a plurality of links. At least one router provides automatic protection switching in the event of a link failure. The at least one router includes a plurality of data interfaces for streams of data packets to enter and exit the at least one router; and a backup controller. The backup controller includes a backup path manager, a link monitor, and a backup packet processor. For at least one link of the routing node, the backup path manager identifies a backup routing path for forwarding affected data packets in the event of a failure of the at least one link. The link monitor monitors the plurality of links to determine when a link fails. When a link which has a backup routing path fails, the backup packet processor attaches backup routing path instructions to affected data packets routed over the failed link, and forwards the affected data packets via the backup routing path.
1. Apparatus comprising:
a backup controller that provides protection switching in the event of a link failure associated with an intermediate routing node that delivers explicitly routed data packets from a source to a destination in a computer network via a plurality of links, including a backup path manager that, for at least one link of the routing node, identifies a backup routing path that is used by the routing node for forwarding affected explicitly routed data packets to the destination in the event of a failure of the at least one link, wherein the backup routing path is determined prior to a failure of the at least one link.
2. The apparatus according to claim 1 , wherein the backup controller further advertises a link failure to the network using a routing protocol.
3. The apparatus according to claim 1 , further comprising a backup packet processor that, when a link which has a backup routing path fails, attaches backup routing path instructions to affected data packets routed over the failed link, and forwards the affected data packets via the backup routing path the backup routing path instructions based on Multi-Protocol Label Switching (MPLS).
4. The apparatus according to claim 3 , wherein the label stack includes labels for a packet source and a packet destination.
5. The apparatus according to claim 1 , wherein the backup routing path is a Label Switched Path (LSP).
6. The apparatus according to claim 5 , wherein the LSP is based on network topology information.
7. The apparatus according to claim 6 , wherein the network topology information is derived from a network protocol.
8. The apparatus according to claim 1 , wherein the computer network uses a label switching routing protocol.
9. A method comprising:
providing protection switching in the event of a link failure associated with an intermediate routing node that delivers explicitly routed data packets from a source to a destination in a computer network, including identifying, for at least one link of the routing node, a backup routing path that is used by the routing node for forwarding affected data packets to the destination in the event of a failure of the at least one link, wherein the backup routing path is identified prior to the failure of the at least one link.
10. A method according to claim 9 , further comprising advertising a link failure to the network using a routing protocol.
11. A method according to claim 9 , further comprising establishing a new network route to replace a failed link.
12. A method according to claim 9 , further comprising using a loop prevention algorithm after a link failure to determine that the network has converged and is loop-free.
13. A method according to claim 9 , further comprising the steps of determining when a link fails, and, when a link which has a backup routing path fails, attaching backup routing path instructions to affected data packets routed over the failed link, wherein the backup routing path instructions include a label stack based on Multi-Protocol Label Switching (MPLS).
14. A method according to claim 13 , wherein the label stack includes labels for a packet source and a packet destination.
15. A method according to claim 9 , wherein the backup routing path is a Label Switched Path (LSP).
16. A method according to claim 15 , wherein the LSP is based on network topology information.
17. A method according to claim 16 , wherein the network topology information is derived from a network protocol.
18. A method according to claim 9 , wherein the computer network uses a label switching routing protocol.