Resource reservation techniques for point-to-multipoint tunnels on a ring network

Patent metadata

Field	Value
Publication number	US-10715428-B2
Application number	US-201816018708-A
Country	US
Kind code	B2
Filing date	Jun 26, 2018
Priority date	Jun 26, 2018
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

Techniques are described for signaling a resource reservation point-to-multipoint (P2MP) label switched path (LSP) in a ring network. For example, the techniques include sending a single resource reservation request message without the ingress needing to send multiple resource reservation request messages, one for each leaf network device of the P2MP ring LSP. The resource reservation request message includes a leaf identification object from which network devices of a P2MP ring LSP may explicitly or implicitly identify themselves as prospective leaf network devices of the P2MP ring LSP. A network device determined to be a leaf network device may send a resource reservation response message back to the ingress network device of the P2MP ring LSP and send a modified resource reservation request message (if explicit) and/or the same resource reservation request message (if implicit) to a next hop network device along the P2MP ring LSP.

First claim

What is claimed is:

1. A method comprising:
receiving, by a network device and from an ingress network device of a ring network, a resource reservation request message to establish a point-to-multipoint (P2MP) ring label switched path (LSP), wherein the resource reservation request message includes a leaf identification object that identifies a plurality of leaf network devices of the P2MP ring LSP;
determining, by the network device and based on the leaf identification object, that the network device is one of the plurality of leaf network devices of the P2MP ring LSP;
sending, by the network device and in response to determining that the network device is one of the plurality of leaf network devices of the P2MP ring LSP and reserving resources according to the resource reservation request message, a resource reservation response message towards the ingress network device;
modifying, by the network device and based on the resource reservation request message, forwarding information of the network device to forward network traffic received on the P2MP ring LSP off of the P2MP ring LSP; and
sending, by the network device and to a next hop network device along the P2MP ring LSP, the resource reservation request message.

2. The method of claim 1 , further comprising:
determining, by the network device, that the resource reservation request message comprises a ring identifier identifying P2MP ring LSP and a direction flag indicated a direction of clockwise or counterclockwise.

3. The method of claim 1 , wherein receiving the resource reservation request message to establish the P2MP ring LSP comprises:
receiving a resource reservation request message that does not specify an Explicit Route Object (ERO) or a Secondary Explicit Route Object (SERO).

4. The method of claim 1 , wherein sending the resource reservation request message comprises:
sending a resource reservation request message that does not specify an Explicit Route Object (ERO) or a Secondary Explicit Route Object (SERO).

5. The method of claim 1 , wherein determining that the network device is one of the plurality of leaf network devices of the P2MP ring LSP comprises:
determining that the leaf identification object includes a network address of the network device.

6. The method of claim 1 , wherein determining that the network device is one of the plurality of leaf network devices of the P2MP ring LSP comprises:
determining, in response to determining that the leaf identification object includes a network address of an ingress network device of the P2MP ring LSP, whether the network device is one of the plurality of leaf network devices of the P2MP ring LSP.

7. The method of claim 1 , wherein sending the resource reservation request message comprises:
modifying, by the network device and in response to determining that the leaf identification object includes a network address of the network device, the leaf identification object by removing the network address of the network device from the leaf identification object to generate a modified leaf identification object; and
sending, by the network device and in response to determining that the modified leaf identification object is not empty and that a path state of the network device for the P2MP ring LSP is newly created, a modified resource reservation request message including the modified leaf identification object to the next hop.

8. The method of claim 1 , wherein sending the resource reservation request message comprises:
modifying, by the network device and in response to determining that the leaf identification object includes a network address of the network device, the leaf identification object by removing the network address of the network device from the leaf identification object to generate a modified leaf identification object; and
sending, by the network device and in response to determining that the modified leaf identification object is not empty and that the leaf identification object is different from a previously sent leaf identification object, a modified resource reservation message including the modified leaf identification object to the next hop.

9. The method of claim 1 , wherein sending the resource reservation request message comprises:
sending, by the network device and in response to determining that the leaf identification object includes a network address of the ingress network device of the P2MP ring LSP, the resource reservation request message including the leaf identification object to the next hop.

10. The method of claim 1 , further comprising:
modifying, by the network device and in response to determining that the leaf identification object includes a network address of the network device, the leaf identification object by removing the network address of the network device from the leaf identification object to generate a modified leaf identification object; and
sending, by the network device and in response to determining that the modified leaf identification object is empty and the leaf identification object is different from a previously received leaf identification object, a path teardown message including the previously received leaf identification object.

11. The method of claim 1 , further comprising:
sending, by the network device and in response to determining that the network device is no longer one of the plurality of leaf network devices of the P2MP ring LSP, a Resource Reservation Protocol (RSVP) reservation teardown message to a previous hop of the P2MP ring LSP.

12. The method of claim 11 , wherein sending the RSVP reservation teardown message to the previous hop of the P2MP ring LSP comprises:
determining, by the network device, that the network device did not receive a resource reservation response message from the next hop network device along the P2MP ring LSP.

13. The method of claim 1 ,
wherein the resource reservation request message comprises a Resource Reservation Protocol (RSVP) path message,
wherein the resource reservation response message comprises an RSVP reservation message, and
wherein the leaf identification object comprises a S2L Sub-LSP Descriptor List object.

14. The method of claim 1 , further comprising:
receiving, by the network device and from the next hop network device along the P2MP ring LSP, a resource reservation response message;
determining, by the network device, that the resource reservation response message is received from the next hop network device along the P2MP ring LSP for the resource reservation request message that was sent to the next hop network device along the P2MP ring LSP;
modifying, by the network device and based on the resource reservation response message, forwarding information of the network device to forward network traffic received on the P2MP ring LSP to the next hop network device along the P2MP ring LSP; and
sending, by the network device and to a previous hop network device along the P2MP ring LSP, the resource reservation response message.

15. A network device comprising:
a plurality of physical interfaces for receiving traffic from two or more network devices of a plurality of network devices in a ring network;
one or more processors configured to:
receive, from an ingress network device of the ring network, a resource reservation request message to establish a point-to-multipoint (P2MP) ring label switched path (LSP), wherein the resource reservation request message includes a leaf identification object that identifies a plurality of leaf network devices of the P2MP ring LSP;
determine, based on the leaf identification object, that the network device i

Assignees

• Juniper Networks Inc

Inventors

• Zhang Zhaohui
• Deshmukh Abhishek
• Singh Ravi

Classifications

• H04L45/48

  Routing tree calculation · CPC title

• H04L45/50 Primary

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

• H04L47/724 Primary

  at intermediate nodes, e.g. resource reservation protocol [RSVP] · CPC title

• H04L47/72

  using reservation actions during connection setup · CPC title

• H04L45/16

  Multipoint routing · CPC title