METHOD AND APPARATUS FOR PATH SWITCHING

• US 20140328166A1
• Filed: 09/27/2011
• Published: 11/06/2014
• Est. Priority Date: 09/27/2011
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Wen, Gan
• Granted Patent: US 9,407,496 B2
• Time in Patent Office: Days
• US Class Current: 370/228
• CPC Class Codes: H04L 41/0663 Performing the actions predefined by failover planning, e.g. switching to standby network elements
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

The present invention discloses a path switching method and apparatus in a network comprising at least a first path and a second path. For an incoming traffic flow, it is determined that any of tunnels on the first path of all levels into which the incoming traffic flow is multiplexed is of a failure status. The incoming traffic flow is then forwarded via the second path. Herein, for the first path, one or more traffic flows are multiplexed into a tunnel, and one or more higher level tunnels are multiplexed into a lower level tunnel.

Claims

1. A path switching method in a network comprising at least a first path and a second path, the method comprising:

for an incoming traffic flow, determining that any of tunnels on the first path of all levels into which the incoming traffic flow is multiplexed is of a failure status; and

forwarding the incoming traffic flow via the second path,

wherein for the first path, one or more traffic flows are multiplexed into a tunnel, and one or more higher level tunnels are multiplexed into a lower level tunnel.

2. The path switching method according to claim 1, wherein the determining step comprises:

judging, from the highest level tunnel, whether the tunnel on each of the levels into which the incoming traffic flow is multiplexed is of the failure status.

3. The path switching method according to claim 1, wherein a failure status is set for an (n+1)th level tunnel if an nth level tunnel into which the (n+1)th level tunnel is multiplexed is set as failure status, wherein n is an integer no smaller than 1.

4. The path switching method according to 1, further comprising:

extracting a forwarding key from the incoming traffic flow, before the determining step; and

determining both a first next hop in the first path and a second next hop in the second path based on the extracted forwarding key.

5. The path switching method according to claim 4, wherein

for forwarding the incoming traffic flow via the second path, the traffic flow is forwarded to the determined second next hop in the second path, and

for forwarding the incoming traffic flow via the first path, the traffic flow is forwarded to the determined first next hop in the first path.

6. The path switching method according to claim 1, further comprising:

for the incoming traffic flow, determining that none of the tunnels on the first path of all levels into which the incoming traffic flow is multiplexed is of the failure status; and

forwarding the incoming traffic flow via the first path.

17. The path switching method according to claim 1, wherein the path switching method is implemented in a router.

18. The path switching method according to claim 1, wherein the failure status of a tunnel is detected by an Operation, Administration, and Management (OAM) protocol.

19. The path switching method according to claim 4, wherein determining both the first next hop in the first path and the second next hop in the second path comprises referring to a forwarding table.

20. The path switching method according to claim 19, wherein determining both the first next hop in the first path and the second next hop in the second path further comprises referring to a next hop working table, a next hop protection table, and a number of group tables each for one level.

7. A path switching apparatus in a network comprising at least a first path and a second path, the apparatus comprising:

a failure status determining unit configured to determine, for an incoming traffic flow, whether any of tunnels on the first path of all levels into which the incoming traffic flow is multiplexed is of a failure status; and

a forwarding unit configured to forward the incoming traffic flow via the second path, if the failure status determining unit determines that any of tunnels on the first path of all levels into which the incoming traffic flow is multiplexed is of the failure status,

wherein for the first path, one or more traffic flows are multiplexed into a tunnel, and one or more higher level tunnels are multiplexed into a lower level tunnel.

8. The path switching apparatus according to claim 7, wherein the failure status determining unit is further configured to judge, from the highest level tunnel, whether the tunnel on each of the levels into which the incoming traffic flow is multiplexed is of the failure status.

9. The path switching apparatus according to claim 7, wherein a failure status is set for an (n+1)th level tunnel if an nth level tunnel into which the (n+1)th level tunnel is multiplexed is set as failure status, wherein n is an integer no smaller than 1.

10. The path switching apparatus according to 7, further comprising:

a next hop determining unit configured to extract a forwarding key from the incoming traffic flow, and determine both a first next hop in the first path and a second next hop in the second path based on the extracted forwarding key.

11. The path switching apparatus according to claim 10, wherein

for forwarding the incoming traffic flow via the second path, the forwarding unit is configured to forward the traffic flow to the determined second next hop in the second path, and

for forwarding the incoming traffic flow via the first path, the forwarding unit is configured to forward the traffic flow to the determined next hop in the first path.

12. The path switching apparatus according to claim 7, wherein the forwarding unit is further configured to forward the incoming traffic flow via the first path if the failure status determining unit determines that none of the tunnels on the first path of all levels into which the incoming traffic flow is multiplexed is of the failure status.

13. The path switching apparatus according to claim 7, wherein the path switching apparatus is a router.

14. The path switching apparatus according to claim 7, wherein the failure status of a tunnel is detected by an Operation, Administration, and Management (OAM) protocol.

15. The path switching apparatus according to claim 10, wherein the next hop determining unit is further configured to refer to a forwarding table in determining both the first next hop in the first path and the second next hop in the second path.

16. The path switching apparatus according to claim 15, wherein the next hop determining unit is further configured to maintain a next hop working table, a next hop protection table, and a number of group tables each for one level.