Label switched path node failure management for label switched paths having refresh interval independent fast reroute facility protection

Patent metadata

Field	Value
Publication number	US-10469365-B2
Application number	US-201414585722-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Oct 27, 2014
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

In one example, techniques of this disclosure may enable a point of local repair (PLR) network device to signal availability of link protection or node protection to a merge point (MP) network device and enable a network device to actively determine whether or not it is a merge point router. Based on whether or not the network device determines it is a MP, the network device may selectively clean up LSP states when there is an upstream link or node failure. The RSVP-TE protocol may be extended to enable a network device to send a tear down message to a downstream router, which may enable the downstream router to conditionally delete locale LSP state information. In some instances, a PLR network device may directly send a tear down message to a MP network device even though the PLR network device may not have a working bypass LSP.

First claim

What is claimed is:

1. A method comprising:
receiving, by a first network device and from a second network device, a remote pathtear message, wherein the first network device and the second network device are part of a label switched path in a network;
responsive to receiving the remote pathtear:
determining, by the first network device, whether the first network device is a merge point for the second network device;
responsive to determining that the first network device is the merge point for the second network device, removing, by the first network device, path information for the label switched path stored by the first network device; and
responsive to determining that the first network device is not a merge point for the second network device, retaining, by the first network device, the path information for the label switched path.

2. The method of claim 1 , further comprising:
responsive to determining that the first network device is the merge point for the second network device, sending, by the first network device, to a downstream network device, a pathtear message instructing the downstream network device to remove state information for the label switched path.

3. The method of claim 1 , wherein the remote pathtear message is a first remote pathtear message, and wherein the second network device is a previous hop network device, the method further comprising:
receiving, by the first network device and from a previous previous hop network device, a second remote pathtear message; and
responsive to receiving the first remote pathtear message from the previous hop and the second remote pathtear message from the previous previous hop, removing, by the network device, the path information for the label switched path.

4. The method of claim 1 , wherein the second network device is a previous previous hop of the first network device, the method further comprising:
receiving, by the first network device, from a previous hop network device, a conditional pathtear message;
responsive to receiving the conditional pathtear message, determining, by the first network device, whether the previous hop network device previously indicated node protection was available; and
responsive to determining that the previous hop network device previously indicated node protection was available, sending, by the first network device and in a downstream direction, a PATH message indicating that node protection and local protection are no longer available.

5. The method of claim 4 , wherein the conditional pathtear message signals that a receiving router is not required to immediately and unconditionally delete the path information for the label switched path.

6. The method of claim 1 , wherein the second network device is a previous previous hop of the first network device, the method further comprising:
receiving, by the first network device, from a previous hop network device, a conditional pathtear message,
wherein removing the path information for the label switched path stored by the first network device is further responsive to receiving the conditional pathtear message.

7. The method of claim 1 , wherein the second network device is a previous previous hop of the first network device, and wherein the first network device does not support enhanced facility protection, the method further comprising:
receiving, by the first network device, from a previous hop network device, a conditional pathtear message, wherein the conditional pathtear message includes an object defining the conditional pathtear message as being of a conditional pathtear message type;
discarding, by the first network device, the object included in the conditional pathtear message; and
processing, by the first network device, the conditional pathtear message as a pathtear message by at least:
removing, by the first network device, the path information for label switched path stored by the first network device; and
sending, by the first network device and to a downstream network device, a pathtear message instructing the downstream network device to remove state information for the label switched path.

8. A first network device comprising:
one or more network interface cards; and
a control unit configured to:
receive, from a second network device and using at least one of the one or more network interface cards, a remote pathtear message, wherein the first network device and the second network device are part of a label switched path in a network;
determine whether the first network device is a merge point for the second network device;
responsive to determining that the first network device is the merge point for the second network device, remove path information for the label switched path stored by the first network device; and
responsive to determining that the first network device is not a merge point for the second network device, retain, by the first network device, the path information for the label switched path.

9. The first network device of claim 8 , wherein the control unit is configured to, responsive to determining that the first network device is the merge point for the second network device, send, to a downstream network device and using at least one of the one or more network interface cards, a pathtear message instructing the downstream network device to remove state information for the label switched path.

10. The first network device of claim 8 ,
wherein the remote pathtear message is a first remote pathtear message,
wherein the second network device is a previous hop network device, and
wherein the control unit is configured to:
receive, from a previous previous hop network device and using at least one of the one or more network interface cards, a second remote pathtear message; and
responsive to receiving the first remote pathtear message from the previous hop and the second remote pathtear message from the previous previous hop, remove the path information for the label switched path.

11. The first network device of claim 8 , wherein the second network device is a previous previous hop of the first network device, and wherein the control unit is further configured to:
receive, from a previous hop network device, a conditional pathtear message;
responsive to receiving the conditional pathtear message, determine whether the previous hop network device previous indicated node protection was available; and
responsive to determining that the previous hop network device previously indicated node protection was available, send, in a downstream direction, a PATH message indicating that node protection and local protection are no longer available.

12. The first network device of claim 8 , wherein the second network device is a previous previous hop of the first network device, and wherein the control unit is further configured to:
receive, from a previous hop network device, a conditional pathtear message; and
remove the path information for the label switched path stored by the first network device further in response to receiving the conditional pathtear message.

13. The first network device of claim 8 , wherein the second network device is a previous previous hop of the first network device, wherein the first network device does not support enhanced facility protection, and wherein the control unit is further configured to:
receive, from a previous hop network device, a conditional pathtear message, wherein the conditional pathtear message includes an object defining the conditional pathtear message as being of a conditional pathtear message type;
discard the object included in the conditional pathtear message; and
process the condi

Assignees

• Juniper Networks Inc

Inventors

• Ramachandran Chandrasekar
• Jork Markus
• Rekhter Yakov
• Sitaraman Harish

Classifications

• H04L41/0654

  using network fault recovery (ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437) · CPC title

• H04L47/72

  using reservation actions during connection setup · CPC title

• H04L45/28 Primary

  using route fault recovery · CPC title

• H04L45/50

  using label swapping, e.g. multi-protocol label switch [MPLS] · CPC title

• H04L41/0668

  by dynamic selection of recovery network elements, e.g. replacement by the most appropriate element after failure · CPC title