Methods and devices for creating an alternate path for a bi-directional LSP

• US 7,508,755 B2
• Filed: 07/07/2003
• Issued: 03/24/2009
• Est. Priority Date: 07/07/2003
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Liu, Hua Autumn
• Primary Examiner(s): Rao, Seema S
• Assistant Examiner(s): Russell, Wanda Z
• Application Number:
  US10/613,103
• Publication Number:
  US 20050007950A1
• Time in Patent Office: 2,087 Days
• Field of Search: 370/221, 370/401, 370/392, 370/389, 370/216, 370/217, 370/227, 370/228, 370/238, 370/244, 370/338, 370/351, 370/352
• US Class Current: 370/228
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

Upon the detection of a failure along a bi-directional label switched path, traffic in both forward and backward directions is re-routed to the same alternate path.

Claims

1. A system for re-routing traffic from a bi-directional Label Switched Path (LSP) comprising:

an originating network device to;

re-route traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction; and

transmit a switch over message along the alternate path in the forward direction to a merging network device responsible for re-routing traffic traveling along the bi-directional LSP in a backward direction to the alternate path in the backward direction.

2. The system of claim 1, wherein the originating network device is further to transmit a second message, along the alternate path in the forward direction, to the merging network device to allow traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected.

3. The system of claim 1, wherein the originating network device is a multi-protocol label switched (MPLS) device.

4. The system of claim 1 wherein the bi-directional LSP is comprised of an LSP carrying traffic in the forward direction and another LSP carrying traffic in the backward direction.

5. The system of claim 1 further comprising a merging network device to receive the switch over message and to re-route traffic traveling along the bi-directional LSP in the backwards direction to the alternate path in the backwards direction based on the switch over message.

6. The system of claim 5, wherein, the merging network device is further to:

receive a second message along the alternate path in the forward direction; and

allow traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected based on said second message.

7. The system of claim 5 wherein the merging network device is a MPLS device.

8. The system of claim 1 further comprising a merging network device which comprises means for receiving the switch over message and means for re-routing traffic traveling along the bi-directional LSP in the backwards direction to the alternate path in the backwards direction based on the switch over message.

9. The system of claim 8, wherein, the merging network device further comprises:

means for receiving a second message along the alternate path in the forward direction; and

means for allowing traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected based on said second message.

10. A merging network device operable to:

receive traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction;

receive a switch over message along the alternative path in the forward direction; and

re-route traffic traveling along a bi-directional LSP in a backwards direction to an alternate path in the backwards direction based on the switch over message.

11. The device as in claim 10 further operable to:

receive a second message along the alternate path in the forward direction; and

allow traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected based on said second message.

12. The device of claim 10 wherein, the merging network device is a MPLS device.

13. A method for re-routing traffic from a bi-directional LSP comprising the steps of:

re-routing traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction; and

transmitting a switch over message along the alternate path in the forward direction to a merging network device responsible for re-routing traffic traveling along the bi-directional LSP in a backward direction to the alternate path in the backward direction.

14. The method of claim 13 further comprising the step of:

transmitting a second message, along the alternate path in the forward direction, to the merging network device to allow traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected.

15. The method of claim 13 wherein the bi-directional LSP is comprised of an LSP carrying traffic in the forward direction and another LSP carrying traffic in the backward direction.

16. The method of claim 13 further comprising the steps of:

receiving the switch over message; and

re-routing traffic traveling along the bi-directional LSP in the backwards direction to the alternate path in the backwards direction based on the switch over message.

17. The method of claim 16 further comprising the steps of:

receiving a second message along the alternate path in the forward direction; and

allowing traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected based on said second message.

18. A method for re-routing traffic comprising the steps of:

receive traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction;

receiving a switch over message along the alternative path in the forward direction; and

re-routing traffic traveling along a bi-directional LSP in a backwards direction to an alternate path in the backwards direction based on the switch over message.

19. The method of claim 18 further comprising the steps of:

receiving a second message along the alternate path in the forward direction; and

allowing traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected based on said second message.

20. A system for re-routing traffic comprising:

an originating network device comprising;

means for re-routing traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction; and

means for transmitting a switch over message along the alternate path in the forward direction to a merging network device responsible for re-routing traffic traveling along the bi-directional LSP in a backward direction to the alternate path in the backward direction.

21. The system of claim 20, wherein the originating network device further comprises means for transmitting a second message, along the alternate path in the forward direction, to the merging network device to allow traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected.

22. The system of claim 20 wherein the bi-directional LSP is comprised of an LSP carrying traffic in the forward direction and another LSP carrying traffic in the backward direction.

23. A merging network device comprising:

means for means for receiving traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction;

receiving a switch over message along the alternative path in the forward direction; and

means for re-routing traffic traveling along a bi-directional LSP in a backwards direction to an alternate path in the backwards direction based on the switch over message.

24. The device as in claim 23 further comprising:

means for receiving a second message along the alternate path in the forward direction; and

means for allowing traffic to travel along the bi-directional LSP in the backward direction when a failure is no longer detected based on said second message.

25. A system for re-routing traffic comprising:

means for re-routing traffic traveling along a bi-directional LSP in a forward direction to an alternate path in the forward direction;

means for transmitting a switch over message, along the alternate path in the forward direction, for re-routing traffic traveling along the bi-directional LSP in a backward direction;

means for receiving the switch over message; and

means for re-routing traffic traveling along the bi-directional LSP in a backwards direction to the same alternate path in the backwards direction based on the switch over message.