Method for determining forwarding path and control device

Patent metadata

Field	Value
Publication number	US-10812372-B2
Application number	US-201916243062-A
Country	US
Kind code	B2
Filing date	Jan 8, 2019
Priority date	Jul 8, 2016
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

Embodiments of the present application provide a method for determining a forwarding path and a control device. The method includes: obtaining a first-forwarding-path computation request, where the first-forwarding-path computation request instructs to compute a first forwarding path that is from a source node to a destination node and that satisfies a first constraint; and when the control device computes at least two forwarding paths that satisfy the first constraint, obtaining, based on a mapping relationship between a path computation reference constraint and a priority, a path computation reference constraint having a highest priority, and determining, based on the path computation reference constraint having the highest priority and from the at least two forwarding paths that satisfy the first constraint, at least one forwarding path that satisfies the path computation reference constraint having the highest priority.

First claim

What is claimed is:

1. A method for determining a forwarding path, applied to a communications network, comprising:
obtaining, by a control device, a first-forwarding-path computation request, wherein the first-forwarding-path computation request instructs to compute a first forwarding path that is from a source node to a destination node, the first forwarding path satisfying a first constraint;
in response to the first-forwarding-path, obtaining one or more forwarding paths based on the first constraint;
when at least two forwarding paths that satisfy the first constraint are obtained through computing, obtaining, by the control device based on mapping relationships between path computation reference constraints and corresponding priorities, a path computation reference constraint having a highest priority, wherein the mapping relationship between path computation reference constraints and priorities comprises N path computation reference constraints Ci and N priorities Pi, wherein
Pi is in a one-to-one correspondence with Ci,
i is a positive integer greater than or equal to 1 and less than or equal to N, and
N is a positive integer greater than or equal to 2, and
N path-computation-reference-constraint state indications Ei, wherein
a given Ei is in a one-to-one correspondence with a given Ci, Ei indicating whether the corresponding Ci is enabled or disabled such that Ei in an enabled state E indicating the corresponding Ci is a path computation reference constraint that can be used for forwarding path computation by the control device; and, wherein obtaining, by the control device based on the mapping relationships between the path computation reference constraints and corresponding priorities, a path computation reference constraint having a highest priority comprises:
selecting, by the control device, one or more Ci in an E enabled state based on Ei, and selecting, from the one or more Ci, the Ci having the highest priority Pi; and

determining, by the control device, based on the path computation reference constraint having the highest priority and from the at least two forwarding paths that satisfy the first constraint, at least one forwarding path that satisfies the path computation reference constraint having the highest priority.

2. The method according to claim 1 , wherein the method further comprises:
when the control device computes at least two forwarding paths that satisfy the path computation reference constraint having the highest priority:
determining, by the control device based on a path computation reference constraint having a second highest priority,
determining, from the at least two forwarding paths that satisfy the path computation reference constraint having the highest priority, a forwarding path that satisfies the path computation reference constraint having the second highest priority, and
when a quantity of the forwarding paths that satisfy the path computation reference constraint having the second highest priority is greater than or equal to 2, sequentially selecting path computation reference constraints corresponding to low-level priorities and determining forwarding paths that satisfy the path computation reference constraints corresponding to the low-level priorities, until one forwarding path that satisfies a path computation reference constraint corresponding to one of the low-level priorities is determined or until a path computation reference constraint corresponding to a lowest-level priority is selected and a forwarding path that satisfies the path computation reference constraint corresponding to the lowest-level priority is determined.

3. The method according to claim 1 , wherein the mapping relationships further comprise:
N path-computation-reference-constraint state indications T i of the first forwarding path, wherein a given T i of the first forwarding path is in a one-to-one correspondence with a given C i , the given T i of the first forwarding path indicating whether the corresponding C i is enabled when the first forwarding path is determined such that Ti of the first forwarding path in an enabled state indicates when the first forwarding path is determined, C i corresponding to T i of the first forwarding path is a path computation reference constraint that can be used for forward path computation by the control device; and, wherein
obtaining, by the control device based on mapping relationships between path computation reference constraints and the corresponding priorities, a path computation reference constraint having a highest priority comprises:
selecting, by the control device, one or more C i in a T enabled state based on T i of the first forwarding path, and then selecting, from the one or more C i , the C i having the highest priority P i .

4. The method according to claim 1 , wherein the mapping relationships further comprise:
N path-computation-reference-constraint state indications Ti of the first forwarding path, wherein a given Ti of the first forwarding path is in a one-to-one correspondence with the corresponding Ci, the given Ti of the first forwarding path indicating whether the corresponding Ci is enabled when the first forwarding path is determined such that Ti of the first forwarding path in an enabled state indicates when the first forwarding path is determined, the corresponding Ci is a path computation reference constraint that can be used for forward path computation by the control device; and
the obtaining, by the control device based on a mapping relationship between path computation reference constraints and a priorities, a path computation reference constraint having a highest priority comprises:
selecting, by the control device, Ci in an E enabled state based on Ei;
selecting Ci in a T enabled state from Ci in an E enabled state based on Ti of the first forwarding path; and
selecting, from Ci in a T enabled state based on Pi, Ci corresponding to a highest priority Pi.

5. The method according to claim 4 , wherein the method further comprises:
when the control device determines that no forwarding path satisfies the first constraint, selecting, by the control device, Pi in a T enabled state based on Ti of the first forwarding path, and then selecting a highest priority Pi from Pi in a T enabled state of the first forwarding path as a preemption priority of the first forwarding path;
obtaining, by the control device, N path-computation-reference-constraint state indications Ti of a second forwarding path, wherein a given Ti of the second forwarding path is in a one-to-one correspondence with a given Pi;
selecting Pi in a T enabled state based on Ti of the second forwarding path,
selecting a highest priority Pi from Pi in a T enabled state of the second forwarding path as a preemption priority of the second forwarding path;
determining that the preemption priority of the second forwarding path is lower than the preemption priority of the first forwarding path; and
preempting, by the control device, a resource of the second forwarding path, and determining at least one forwarding path that satisfies the first constraint.

6. The method according to claim 5 , wherein the mapping relationships further comprise N path-computation-reference-constraint state indications Ei, wherein a given Ei is in a one-to-one correspondence with a given Ci, Ei indicating whether the corresponding Ci is enabled such that Ei in an enabled state indicates corresponding Ci is a path computation reference constraint that can be used for the forward path computation by the control device, wherein selecting, by the control device, Pi in a T enabled state based on Ti of the first forwarding path, and then selecting a highest priority Pi from Pi in a T enabled state of the first forwarding path as a preemption prio

Assignees

• Huawei Tech Co Ltd

Inventors

• Long Yong

Classifications

• H04L45/302

  Route determination based on requested QoS · CPC title

• H04L45/64

  using an overlay routing layer · CPC title

• H04L45/42 Primary

  Centralised routing · CPC title

• H04L45/123 Primary

  Evaluation of link metrics (techniques for monitoring network metrics H04L43/08) · CPC title

• H04L45/124

  using a combination of metrics · CPC title