Packet sending method, network node, and system

Patent metadata

Field	Value
Publication number	US-11706149-B2
Application number	US-202017035687-A
Country	US
Kind code	B2
Filing date	Sep 29, 2020
Priority date	Mar 29, 2018
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

A controller obtains a forwarding latency requirement of a service flow and a destination address of the service flow, and determines a forwarding path that meets the forwarding latency requirement. The controller determines that an ingress node forwards a first cycle time number of a packet and an intermediate node forwards a second cycle time number of the packet, and separately determines a corresponding adjacent segment identifier. A label stack generated by the controller includes the adjacent segment identifier and the adjacent segment identifier. The controller sends the label stack to the ingress node, to trigger the ingress node to forward the packet within a period of time corresponding to the first cycle time number. The controller determines the forwarding path based on the forwarding latency requirement of the service flow, and generates a label stack corresponding to a forwarding time point.

First claim

What is claimed is:

1. A packet sending method using cyclic queueing and forwarding, CQF, comprising:
obtaining, by a controller, a node latency of the first network node and a node latency of the second network node, wherein each node latency comprises a packet processing latency and a packet sending latency;
obtaining, by the controller, a link latency of a link on the forwarding path;
obtaining, by the controller, a forwarding latency requirement of a service flow and a destination address of the service flow;
calculating, based on the forwarding latency requirement and the destination address, a forwarding path for forwarding the service flow, wherein a latency of the forwarding path meets the forwarding latency requirement of the service flow, the forwarding path passes through a first network node, a second network node, and a third network node, the first network node is an ingress node of the forwarding path, the second network node is an intermediate node of the forwarding path, and the third network node is an egress node of the forwarding path, and further wherein the first network node, the second network node, and the third network node are located is a segment routing network;
obtaining, by the controller, a cycle duration of the first network node and a cycle duration of the second network node;
determining, by the controller, a first cycle number at which the first network node forwards a packet based on the cycle duration of the first network node and further determining a second cycle number at which the second network node forwards the packet, the second cycle number based on the cycle duration of the first network node;
determining a first adjacent segment identifier corresponding to the first cycle number and a second adjacent segment identifier corresponding to the second cycle number, wherein the packet is in the service flow;
wherein each network node has a packet receiving queue and a packet sending queue and each network node further has a clock, wherein the packet receiving queue and the packet sending queue exchange their roles after a fixed-length period of time, the fixed-length period of time being defined as a cycle, wherein sending of a packet in the packet sending queue is completed once in the cycle; and further
wherein a correspondence between each adjacent segment identifier and a cycle number is established wherein an outbound interface of each network node corresponds to a plurality of adjacent segment identifiers, and a segment identifier corresponding to a port of a node is an adjacent segment identifier;
generating, by the controller, a label stack, wherein the label stack comprises sequentially, from a top of the stack to a bottom of the stack, the first adjacent segment identifier and the second adjacent segment identifier;
sending, by the controller, the label stack to the first network node, wherein the label stack is used to indicate the first network node to forward the packet via the forwarding path within a period of time corresponding to the first cycle number; and
forwarding the packet, by the first network node based on the label stack at a cycle number which is determined according to the correspondence between an adjacent segment identifier and the cycle number.

2. The method according to claim 1 , wherein
the latency of the forwarding path meets the forwarding latency requirement of the service flow when a sum of the node latency of the first network node, the node latency of the second network node, and the link latency of the link on the forwarding path falls within a range of the forwarding latency requirement of the service flow.

3. The method according to claim 1 , wherein the method further comprises:
obtaining, by the controller, a third cycle number of the first network node and a fourth cycle number of the second network node that are corresponding to a current time point of the controller;
determining, by the controller, the third cycle number wherein a start time point corresponding to the first cycle number is after the first network node receives the label stack; and
determining, by the controller, a link latency between the first network node to the second network node, the packet processing latency of the second network node, the third cycle number, and the cycle duration of the second network node.

4. The method according to claim 1 , wherein the method further comprises:
receiving, by the controller, a notification packet sent by the first network node, wherein the notification packet comprises the forwarding latency requirement and the destination address of the packet.

5. A controller, comprising a processor and a memory, the controller adapted to perform the steps of:
obtaining a node latency of the first network node and a node latency of the second network node, wherein each node latency comprises a packet processing latency and a packet sending latency;
obtaining a link latency of a link on the forwarding path;
obtaining a cycle duration of the first network node and a cycle duration of the second network node;
determining a first cycle number at which the first network node forwards a packet based on the cycle duration of the first network node and further determines a second cycle number at which the second network node forwards the packet, the second cycle number based on the cycle duration of the first network node;
determining a first adjacent segment identifier corresponding to the first cycle number and a second adjacent segment identifier corresponding to the second cycle number, wherein the packet is in the service flow;
wherein each network node has a packet receiving queue and a packet sending queue and each network node further has a clock, wherein the packet receiving queue and the packet sending queue exchange their roles after a fixed-length period of time, the fixed-length period of time being defined as a cycle, wherein sending of a packet in the packet sending queue is completed once in the cycle;
generating a label stack, wherein the label stack comprises sequentially, from a top of the stack to a bottom of the stack, the first adjacent segment identifier and the second adjacent segment identifier; and
sending the label stack to the first network node, wherein the label stack is used to indicate the first network node to forward the packet via the forwarding path within a period of time corresponding to the first cycle number.

6. The controller according to claim 5 , wherein the controller is further adapted to perform the further steps of:
the latency of the forwarding path meets the forwarding latency requirement of the service flow when a sum of the node latency of the first network node, the node latency of the second network node, and the link latency of the link on the forwarding path falls within a range of the forwarding latency requirement of the service flow.

7. The controller according to claim 5 , wherein the controller is further adapted to perform the further steps of:
obtaining a third cycle number of the first network node and a fourth cycle number of the second network node that are corresponding to a current time point of the controller;
determining the first cycle number wherein a start time point corresponding to the first cycle number is after the first network node receives the label stack;
determining a link latency between the first network node and the second network node, the packet processing latency of the second network node, the third cycle number, and the cycle duration of the second network node.

8. The controller according to claim 5 , wherein the controller is further adapted to perform the further steps of:
receiving a notification packet sent by the first network node, wherein the notification p

Assignees

• Huawei Tech Co Ltd

Inventors

• Geng Xuesong
• Chen Guoyi

Classifications

• H04L47/28 Primary

  in relation to timing considerations · CPC title

• H04L45/121 Primary

  by minimising delays · CPC title

• H04L45/74

  Address processing for routing · CPC title

• H04L45/30 Primary

  Routing of multiclass traffic · CPC title

• H04L45/50

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