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

Patent metadata

Field	Value
Publication number	US-10187301-B2
Application number	US-201715450851-A
Country	US
Kind code	B2
Filing date	Mar 6, 2017
Priority date	Oct 27, 2014
Publication date	Jan 22, 2019
Grant date	Jan 22, 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, 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, wherein the first resource reservation path message specifies whether local protection is desired for the label switched path; and
responsive to determining that the first resource reservation request message specifies that local protection is desired and responsive to receiving a resource reservation response message from a next hop network device toward the third 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; and
sending, by the first network device and to the next hop network device along the label switched path, a 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, wherein the merge point network device is a first merge point network device, wherein the bypass label switched path between the first network device and the first merge point network device is a first bypass label switched path, and wherein the first bypass label switched path bypasses a protected network link positioned between the first network device and the first merge point network device, the method further comprising:
responsive to determining that the first resource reservation request message specifies that local protection and node protection is desired:
establishing, by the first network device, a second bypass label switched path between the first network device and a second merge point network device, wherein the second bypass label switched path bypasses a protected network device positioned between the first network device and the second merge point network device; and
generating, by the first network device, the second resource reservation path message specifying that node protection is available.

3. 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.

4. 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.

5. 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.

6. The method of claim 1 , wherein the first resource reservation path message includes an enhanced facility protection flag, and wherein the resource reservation response message is a first resource reservation response 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 response 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 response message.

7. The method of claim 1 , wherein the resource reservation response message is a first resource reservation response message, the method further comprising:
receiving, by the first network device, from the next hop next device, a second resource reservation response 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 response 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.

8. The method of claim 1 , wherein the resource reservation response message is a first resource reservation response 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 response 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 response message.

9. The method of claim 1 , wherein the resource reservation response message is a first resource reservation response 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 the first network device and based at least in part on the enhanced facility protection flag of the resource reservation hello message, whether the second network device supports enhanced facility protection; and
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, the second resource reservation path message such that the second resource reservation path messages specifies a refresh time value that is smaller than if the next hop network device did support enhanced facility protection fast reroute.

10. The method of claim 1 , wherein the first resource reservation path message specifies a refresh interval of at least one minute.

11. The method of claim 1 , wherein the first resource reservation path message further specifies whether node protection is desired, wherein the merge point network device is a first merge point network device, wherein the bypass label switched path between the first network device and the first merge point network device is a first bypass label switched path, and wherein the first bypass label switched path bypasses a

Assignees

• Juniper Networks Inc

Inventors

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

Classifications

• H04L47/72

  using reservation actions during connection setup · CPC title

• H04L45/50

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

• 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

• H04L45/026

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

• H04L45/28 Primary

  using route fault recovery · CPC title