Refresh interval independent fast reroute facility protection tear down messaging

Patent metadata

Field	Value
Publication number	US-10182003-B2
Application number	US-201715450858-A
Country	US
Kind code	B2
Filing date	Mar 6, 2017
Priority date	Oct 27, 2014
Publication date	Jan 15, 2019
Grant date	Jan 15, 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 message that instructs the first network device to delete state information for a label switched path in a network if the first network device is not a node protecting merge point for the second network device along the label switched path or a link protecting merge point; and
responsive to determining, by the first network device, that the first network device is the node protecting merge point network device for the second network device along the label switched path:
retaining, with the first network device, state information for the label switched path; and
sending, from the first network device to a third network device, a resource reservation path message that specifies local protection and node protection of the label switch path are no longer available at the second network device.

2. The method of claim 1 , wherein the message is a first message, the method further comprising:
receiving, by the first network device and from a fourth network device, a second message that instructs the first network device to delete state information for a label switched path in a network if the first network device is not a node protecting merge point for the second network device along the label switched path or a link protecting merge point; and
responsive to receiving the second message and responsive to determining, by the first network device, that the first network device is not a node protecting merge point network device for the fourth network device:
removing, by the first network device, the state information for the label switched path; and
sending, by the first network device and to a next hop network device in a downstream direction along the label switched path, a resource reservation message that instructs the next hop network device to delete state information for the label switched path.

3. The method of claim 1 , wherein determining, by the first network device, that the first network device is a node protecting merge point network device for the second network device comprises:
determining, by the first network device, based on a resource reservation path message received from the second network device, whether the first network device is a candidate merge point;
determining, by the first network device, whether there is a remote hello session with the second network device; and
responsive to determining that the first network device is a candidate merge point and determining that there is the remote hello session with the second network device, determining, by the first network device, that the first network device is the node protecting merge point for the second network device.

4. The method of claim 1 , further comprising:
determining, by the first network device, whether the second network device supports enhanced facility protection,
wherein retaining the state information for the label switched path and sending the resource reservation path message are further responsive to determining that the second network device supports enhanced facility protection.

5. The method of claim 1 , further comprising:
determining, by the first network device, whether the second network device supports enhanced facility protection; and
responsive to determining that the second network device does not support enhanced facility protection:
removing, by the first network device, the state information for the label switched path; and
sending, by the first network device, to a downstream network device, a resource reservation pathtear message.

6. The method of claim 1 , wherein the message comprises a resource reservation pathtear message that includes an object identifying the resource reservation pathtear message as a conditional pathtear message.

7. The method of claim 1 , wherein the message is a first message, the method further comprising:
receiving, by a first network device and from a fourth network device, a second message that instructs the first network device to delete state information for a label switched path in a network if the first network device is not a node protecting merge point for the second network device along the label switched path or a link protecting merge point; and
responsive to receiving the second message and responsive to determining, by the first network device, that the first network device is not a node protecting merge point network device for the fourth network device:
determining, by the first network device, whether a remote Hello session between the first network device and a point of local repair network device associated with the first network device is up; and
responsive to determining that there is the remote hello session is up, retaining, by the first network device, the 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 using at least one of the one or more network interface cards, a message that instructs the first network device to delete state information for a label switched path in a network if the first network device is not a link protecting merge point or a node protecting merge point for the second network device along the label switched path; and
responsive to determining that the first network device is the node protecting merge point network device for the second network device along the label switched path:
retain state information for the label switched path; and
send, to a third network device and using at least one of the one or more network interface cards, a resource reservation path message that specifies local protection and node protection of the label switch path are no longer available at the second network device.

9. The first network device of claim 8 ,
wherein the message is a first message, and
wherein the control unit is configured to:
receive, from a fourth network device using at least one of the one or more network interface cards, a second message that instructs the first network device to delete state information for a label switched path in a network if the first network device is not a node protecting merge point for the second network device along the label switched path or a link protecting merge point; and
responsive to receiving the second message and responsive to determining that the first network device is not a node protecting merge point network device for the fourth network device:
remove the state information for the label switched path; and
send, to a next hop network device in a downstream direction along the label switched path and using at least one of the one or more network interface cards, a resource reservation message that instructs the next hop network device to delete state information for the label switched path.

10. The first network device of claim 8 ,
wherein the control unit is configured to:
determine, based on a resource reservation path message received from the second network device, whether the first network device is a candidate merge point;

determine whether there is a remote hello session with the second network device; and
responsive to determining that the first network device is a candidate merge point and determining that there is the remote hello session with the second network device, determine that the first network device is the node protecting merge point for the second network device.

11. The first network device of claim 8 ,
wherein the control unit is configured to:
determine whether the second network device supports enhanced facility protection; and
respo

Assignees

• Juniper Networks Inc

Inventors

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

Classifications

• H04L45/28 Primary

  using route fault recovery · CPC title

• H04L45/507

  Label distribution · CPC title

• H04L45/026

  Details of "hello" or keep-alive messages · 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

• H04L45/50

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