Establishing label switched paths having refresh interval independent fast reroute facility protection

Patent metadata

Field	Value
Publication number	US-9590894-B2
Application number	US-201414585664-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Oct 27, 2014
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

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, with a first network device and from a second network device, a first resource reservation path message for establishing a label switched path between the second network device and a third network device by way of the first network device such that the first network device is positioned between the second network device and the third network device along the label switched path, wherein the first resource reservation path message specifies whether local protection is desired for the label switched path;
sending, by the first network device, the first resource reservation path message to a next hop network device toward the third network device along the label switched path; and
responsive to determining that the first resource reservation path message specifies that local protection is desired and responsive to receiving a resource reservation resv message from the next hop network device:
establishing, by the first network device, a bypass label switched path between the first network device and a merge point network device along the label switched path, wherein the bypass label switched path bypasses a protected network resource positioned along the label switched path between the first network device and the merge point network device;
generating, by the first network device, a second resource reservation path message that specifies that local protection has been established for the label switched path at the first network device; and
sending, by the first network device and to the next hop network device along the label switched path, the second resource reservation path message.

2. The method of claim 1 , wherein the first resource reservation path message further specifies whether node protection is desired, the method further comprising:
responsive to determining that the first resource reservation path message specifies that local protection and node protection is desired:
establishing, by the first network device, a bypass label switched path between the first network device and the merge point network device, wherein the bypass label switched path bypasses a protected network device positioned between the first network device and the merge point network device; and
generating, by the first network device, the second resource reservation path message specifying that node protection is available; and

responsive to determining that the first resource reservation path message specifies that local protection is desired and that node protection is not desired:
establishing, by the first network device, a bypass label switched path between the first network device and the merge point network device, wherein the bypass label switched path bypasses a protected network link positioned between the first network device and the merge point network device; and
generating, by the first network device, the second resource reservation path message specifying that link protection is available.

3. The method of claim 2 , wherein the first resource reservation path message includes a local protection flag and a node protection flag, wherein the first resource reservation path message specifies that local protection is desired when the local protection flag is set, and wherein the first resource reservation path message specifies that node protection is desired when the node protection flag is set.

4. The method of claim 1 , wherein the first resource reservation path message includes a local protection flag, and wherein the first resource reservation path message specifies that local protection is desired when the local protection flag is set.

5. The method of claim 1 , wherein the second resource reservation path message that specifies local protection is available by at least including a protection availability flag that is set.

6. The method of claim 1 , further comprising:
sending, by the first network device, a remote resource reservation hello message, wherein a destination address of the remote resource reservation hello message is an address of the merge point network device, wherein the merge point network device is a next next hop of the first network device; and
receiving, by the first network device and from the merge point network device, a remote resource reservation hello message ack message sent in response to the remote resource reservation hello message.

7. The method of claim 1 , wherein the first resource reservation path message includes an enhanced facility protection flag, and wherein the resource reservation resv message is a first resource reservation resv message, the method further comprising:
determining, by the first network device and based at least in part on the enhanced facility protection flag of the first resource reservation path message, whether the second network device supports enhanced facility protection;
responsive to determining, by the first network device, that the second network device does not support enhanced facility protection, generating, by the first network device, a second resource reservation resv message that specifies a refresh time value that is smaller than if the second network device did support enhanced facility protection; and
sending, from the first network device to the second network device, the resource reservation resv message.

8. The method of claim 1 , wherein the resource reservation resv message is a first resource reservation resv message, the method further comprising:
receiving, by the first network device, from the next hop device, a second resource reservation resv message that includes an enhanced facility protection flag;
determining, by the first network device and based at least in part on the enhanced facility protection flag of the second resource reservation resv message, whether the next hop network device supports enhanced facility protection;
responsive to determining, by a first network device, that the next hop network device does not support enhanced facility protection fast reroute, generating, by the first network device, a third resource reservation path message that specifies a refresh time value that is smaller than if the second network device did support enhanced facility protection fast reroute; and
sending, from the first network device to the next hop network device, the third resource reservation path message.

9. The method of claim 1 , wherein the resource reservation resv message is a first resource reservation resv message, the method further comprising:
receiving, by the first network device, from the second network device, a resource reservation hello message that includes an enhanced facility protection flag;
determining, by the first network device and based at least in part on the enhanced facility protection flag of the first resource reservation hello message, whether the second network device supports enhanced facility protection;
responsive to determining, by a first network device, that the second network device does not support enhanced facility protection fast reroute, generating, by the first network device, a second resource reservation resv message that specifies a refresh time value that is smaller than if the second network device did support enhanced facility protection fast reroute; and
sending, from the first network device to the second network device, the second resource reservation resv message.

10. The method of claim 1 , wherein the resource reservation resv message is a first resource reservation resv message, the method further comprising:
receiving, by the first network device, from the next hop network device, a resource reservation hello message that includes an enhanced facility protection flag;
determining, by

Assignees

• Juniper Networks Inc

Inventors

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

Classifications

• H04L47/728

  for backup paths · CPC title

• H04L45/28 Primary

  using route fault recovery · CPC title

• H04L41/0668

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

• H04L45/026

  Details of "hello" or keep-alive messages · CPC title

• H04L45/507

  Label distribution · CPC title