WO2022007244A1

WO2022007244A1 - Cloud computing-based method for smart link selection in sd-wan network

Info

Publication number: WO2022007244A1
Application number: PCT/CN2020/123140
Authority: WO
Inventors: 魏小兰
Original assignee: 杭州网银互联科技股份有限公司
Priority date: 2020-07-06
Filing date: 2020-10-23
Publication date: 2022-01-13
Also published as: CN111835639B; CN111835639A

Abstract

A cloud computing-based method for smart link selection in an SD-WAN network, which belongs to the technical field of networks. The method is applied to a client device and comprises: step S10, establishing a plurality of communication links between a client device and a plurality of edge routers deployed in a cloud environment; step S20, detecting the network conditions of the communication links; step S30, according to the detected network conditions, evaluating the levels of quality of the links; step S40, according to the levels of quality of the links, determining a link having the highest level of quality among the links as a main link, and determining the others as standby links; and step S50, setting the routing of the client device according to the determined main link and standby links. By means of periodic active detection, the present invention promptly evaluates the level of quality of a network, intelligently selects a relatively optimal link for the network, and fully considers the actual usage needs of users.

Description

An intelligent link selection method for SD-WAN network based on cloud computing

technical field

The invention belongs to the field of network technology, and in particular relates to a cloud computing-based SD-WAN network intelligent link selection method.

Background technique

Two basic components of a traditional enterprise network: (1) network equipment such as routers, switches, and VPN gateways; (2) enterprise-level line resources such as MPLS/MSTP. Although line resources can meet a certain SLA (Service Level Agreement, which is defined by delay, packet loss rate, jitter, bandwidth, etc.), but in reality, the network environment is changing all the time and is very complex. Even if there is a combination of good network equipment and high-quality line resources, it cannot guarantee that enterprise IT applications can Satisfactory results are obtained, such as: (1) Network resources cannot be used reasonably, for example, during peak hours of Internet access, the network is congested and line resources are insufficient, and during idle periods, expensive dedicated network lines cannot be fully utilized; (2) Network quality Unsatisfactory, unstable network, slow Internet access, etc. Although enterprises can improve network experience by purchasing line resources with higher-level SLA, it will inevitably increase costs.

The application of SD-WAN technology solves the above problems to a large extent, makes the enterprise network resources more fully utilized, and the network quality is greatly improved. To a certain extent, the SD-WAN operating network is a replacement for enterprise-level line resources, while SD-WAN CPE (Customer Periphery Equipment, hereinafter referred to as CPE) is a replacement for various enterprise network WAN side equipment. The SD-WAN operation network can provide users with a stable and high-quality network in the cloud, but the network stability between the customer gateway (CPE) and the SD-WAN cloud network cannot be guaranteed. At present, the common method is to provide multiple links between the CPE and the SD-WAN cloud network, that is, the CPE and multiple VPEs (Virtual Provider Edge, the edge router of the service provider's backbone network, deployed on the cloud, including public cloud and private cloud) to establish a connection, select one of the links as the main link, the other links are backup links, only the main link is broken On, the backup link will be selected. However, due to the constantly changing network environment, the main link may not be the optimal link from the CPE to the SD-WAN cloud network.

Invention patent CN201210539033.4 discloses a method for switching between active and standby links, and specifically discloses that the method is applied to wireless routing equipment. The wireless routing equipment dials into the active link through the first wireless modem module, and uses the second wireless modem The module dial-up accesses the backup link, and the method includes the following steps: A. Establishing a unified link signal quality judgment standard for judging the signal quality of the main link and the backup link, and setting switching conditions according to the link signal quality; B. . Detect the signal quality of the primary link and the backup link in real time; C. When it is judged that the detected signal quality meets the set switching conditions, start the switching procedure to switch the primary link and the backup link; determine the link signal quality The standard means: in the set or configured time y1, if the current signal strength value s read in the time exceeding a certain proportion of z1 is lower than the lower signal strength threshold value x1, the link signal quality is judged to be poor, and the z1 is the set or configured time percentage for judging that the link signal quality satisfies the lower threshold x1; within the set or configured y2 time, the current signal strength value s read in the time exceeding a certain proportion of z2 is all higher than the upper threshold threshold x2 of the signal strength, then it is judged that the quality of the link signal is good, and the z2 is the set or configured time percentage for judging that the quality of the link signal satisfies the upper threshold x2; the x1 and x2 are in manual mode Configurable below, calculated dynamically in automatic mode. The method is applied to a wireless routing device, and the main link and the backup link are predetermined, and the main link or the backup link is switched and selected by judging the signal quality of the link.

technical solutions

Aiming at the problems existing in the prior art, the present invention proposes a cloud computing-based SD-WAN network intelligent link selection method, so that the client device and the SD-WAN cloud network can dynamically change between the client device and the SD-WAN cloud network according to the real-time state of the network link. Adjust the main link to improve network speed and user experience.

The present invention is achieved through the following technical solutions:

A cloud computing-based SD-WAN network intelligent link selection method, applied to a client device, comprising:

Step S10, establishing multiple communication links between the client device and multiple edge routers deployed in the cloud environment;

Step S20, detecting the network status of each communication link;

Step S30, evaluating the quality level of each link according to the detected network conditions;

Step S40, according to the quality level of each link, determine that one of the links with the highest quality level is the primary link, and the others are backup links;

Step S50, setting the route of the client device according to the determined primary link and backup link.

Multiple edge routers (VPE, Virtual Provider Edge), VPE provides multiple optional link exits for client devices, and is also the entrance of SD-WAN cloud network. An IPSec VPN tunnel is established between the client device and multiple VPEs. The IPSec VPN provides a secure communication channel for two private networks on the public network, and ensures the security of the connection between the client device and the VPE through the encrypted channel. The client device deployed at the enterprise network egress as the enterprise gateway can intelligently select the optimal link between the current client device and the SD-WAN cloud network for users, ensuring network security and stability.

Preferably, the client device is a CPE device or a VCPE device.

The method of the present invention is suitable for CPE equipment, VCPE (Virtual Customer Periphery Equipment, VCPE for short, Linux host based on x86 platform, or docker service image).

Preferably, step S20 includes:

Step S21, sends periodic detection instructions to each link to obtain the detection results of each communication link;

Step S22, according to the detection result, obtain the packet loss rate, average delay value, and jitter value of each link, and obtain the bandwidth ratio of each link.

Preferably, step S30 includes:

Step S31, according to the detected network state, including the packet loss rate, the average delay value, and the jitter value, compare the packet loss rate evaluation standard table, the average delay value evaluation standard table, and the jitter value evaluation standard table, respectively, to determine the packet loss of each link. Evaluation level, average delay evaluation level, jitter evaluation level;

Step S32, according to the bucket law, the worst level in the packet loss evaluation level, average delay evaluation level, and jitter evaluation level in each link is used as the quality level of the link, and the quality level of all links is determined in this way. .

Preferably, the step S31 includes:

Step S311, according to the network state of periodic detection, each link has the packet loss rate, average delay value, and jitter value of multiple periodic detections; according to the weighting algorithm, determine the weighted packet loss rate and the weighted average delay of each link. value, weighted jitter value;

Step S312, compare the packet loss rate determined by each link with the packet loss rate evaluation standard table to obtain the packet loss evaluation level of each link; compare the average delay value determined by each link with the average delay value evaluation standard table to obtain Average delay evaluation level of each link; compare the jitter value determined for each link with the jitter value evaluation standard table to obtain the jitter evaluation level of each link.

Preferably, step S40 includes:

When one of the following conditions A, B, and C is detected, according to the quality level of each link, the one with the highest quality level among the links is determined as the primary link, and the others are standby links:

A. The main link is not set in the current network;

b. The link whose quality level changes in the current network is the current main link, and the quality level of the current main link becomes lower and the network is unavailable;

c. The link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes lower and the network is in a busy state.

Preferably, when there are two or more links with the highest quality level in each link, according to the evaluation level of the key options of the link, the link with the optimal evaluation level is selected as the main link, wherein the key The options are one of packet loss, average delay, and jitter.

Preferably, situation C includes: when it is detected that the link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes lower and the network is in a busy state, according to the quality level of each link , select the one with the highest quality level in the current standby link. If the quality level of the current standby link is higher than that of the current primary link, and the bandwidth of the current standby link is greater than that of the current primary link, select the current standby link. The standby link is the primary link.

Preferably, the step S40 further includes: when it is detected that the link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes higher and equal to the quality level of the current primary link, and the current The primary link satisfies the condition that the current primary link bandwidth ratio is lower than the bandwidth ratio threshold, and the current backup link satisfies the evaluation level of the key option of the current backup link is higher than the evaluation level of the same key option of the current primary link. When conditions are met, the current standby link is selected as the primary link; the key options are one of packet loss, average delay, and jitter.

Preferably, the step S40 further includes:

When it is detected that the link whose quality level has changed in the current network is a backup link, and the quality level of the current backup link becomes higher and higher than that of the current primary link, and the current backup link satisfies that the bandwidth of the current backup link is greater than that of the current backup link When the bandwidth of the primary link is satisfied, the current backup link is selected as the primary link;

When it is detected that the link whose quality level has changed in the current network is a backup link, and the quality level of the current backup link becomes higher and higher than that of the current primary link, and the current backup link satisfies that the bandwidth of the current backup link is less than or equal to The current primary link bandwidth condition, and the current primary link satisfies the condition that the current primary link bandwidth ratio is lower than the bandwidth ratio threshold and the current primary link network traffic is less than the current backup link bandwidth, select the current backup link main link.

Preferably, the step S40 further includes:

When one of the following conditions a, b, c, d, and e is detected, it is determined that the current primary link is still the primary link:

a. The link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes higher;

b. The link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes lower;

c. The link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes higher and lower than the quality level of the current primary link;

d. The link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes higher and equal to the quality level of the current primary link, and the bandwidth ratio of the current primary link cannot be lower than the bandwidth ratio. The condition of the threshold or the evaluation level of the key option of the current standby link is better than the evaluation level of the same key option of the current main link, where the key option is one of packet loss, average delay, and jitter;

e. The link whose quality level changes in the current network is the standby link, and the quality level of the current standby link becomes higher and higher than the quality level of the current primary link, and the current standby link bandwidth is less than or equal to the current primary link bandwidth. The condition or the condition that the bandwidth ratio of the current active link is lower than the bandwidth ratio threshold or the condition that the network traffic of the current active link is less than the bandwidth of the current backup link.

Preferably, the step S50 includes:

If the current network does not set the primary link and the backup link, set the route of the client device according to the primary link and the backup link determined in step S40;

If the current network has set the primary link and the backup link and the primary link and the backup link change, delete the original route setting, and set the route of the client device according to the primary link and the backup link re-determined in step S40.

beneficial effect

The present invention has the following beneficial effects:

A cloud computing-based SD-WAN network intelligent link selection method,

(1) It can intelligently select the relatively optimal link for the SD-WAN network, improve the network speed and improve the user experience. According to the inventive method, each time the route is selected, the current quality is relatively best, and the actual use requirements of the user are considered.

(2) Reduce network shocks and stabilize the network environment. The network environment is constantly changing. Instantaneous flapping of a link should not cause link changes. Otherwise, frequent link changes may cause network flapping. When evaluating the link level, using the weighted packet loss rate, average delay, and jitter instead of the latest link packet loss rate, average delay, and jitter will greatly reduce network oscillations, and the trade-off of bandwidth ratio , will also make the network more stable.

Description of drawings

1 is a general flowchart of a cloud computing-based SD-WAN network intelligent link selection method of the present invention;

Figure 2 shows the SD-WAN cloud network topology.

Embodiments of the present invention

The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

As shown in Figure 1, a cloud computing-based SD-WAN network intelligent link selection method of the present invention is applied to client equipment, and the method includes:

Step S20, detecting the network status of each communication link;

Before executing steps S20 to S50, an SD-WAN network environment is constructed first. After the network environment is constructed, the intelligent link selection process can be performed according to steps S20-S50. In step S10, the SD-WAN network environment is mainly constructed by the client device and multiple edge routers deployed in the cloud environment, and an IPSec VPN tunnel is constructed between the client device and the edge router, and the tunnel is a secure communication channel, Secure communication between client devices and edge routers is ensured. The client device may be a CPE device or a VCPE device (FIG. 2 shows a communication connection between a CPE device and a VPE device, and a network topology diagram of a communication connection between a VCPE device and a VPE device). The method of the present invention is not limited to an SD-WAN network constructed with only CPE equipment and multiple VPE equipment, nor is it limited to an SD-WAN network constructed with only VCPE equipment and multiple VPE equipment, nor is it limited to having both CPE equipment and VCPE equipment. SD-WAN network built with multiple VPE devices separately.

In step S20, the client device detects the network status of the communication link, mainly detecting the IPSec VPN link. Specifically, the step S20 includes:

The client device includes a network detection module, which is used to actively initiate periodic detection instructions for each link, such as ICMP packets or UDP packets, and the detection destination is a VPE device. A certain number of packets are sent in each cycle, for example, 20 packets are sent in one cycle, and the cycle is 5 seconds. Then, according to the detection results, the packet loss rate, average delay value, and jitter value of the detection packets of each link are obtained. In addition, obtain the bandwidth ratio of each link. The higher the bandwidth ratio, the busier the link.

Specifically, the calculation method of the bandwidth ratio is as follows: assuming that between two detections, the link receives packets as r, the total amount of packets sent is s, the detection period is t, the bandwidth is B, and the bandwidth ratio is b , the calculation formula is as follows:

.

After the client device receives the detection result, step S30 is performed. Specifically, step S30 includes:

Among them, the packet loss rate evaluation standard table is a table that stores the packet loss rate and the evaluation level of the packet loss rate in one-to-one correspondence, and the average delay value evaluation standard table is a table that stores the average delay value and the evaluation level of the average delay value in one-to-one correspondence. The jitter value The evaluation standard table is a table that stores jitter values and jitter value evaluation grades in one-to-one correspondence. The above-mentioned packet loss rate evaluation standard table, average delay value evaluation standard table, and jitter value evaluation standard table are preset and stored in the client device. The evaluation standard can be set according to the actual situation. For example, the network packet loss setting standard mainly depends on the packet loss rate. Excellent: Packet loss rate 0; Good: Packet loss rate (0,5%]; Poor: Packet loss rate (5%, 90%]; Unavailable: Packet loss rate (90%, 100%]. For example , the average network delay can be set as a standard, excellent: [0, 60 ms], good: (60 ms, 120 ms], difference: (120 ms, 300ms], unavailable: more than 300ms. For example, jitter has a great impact on real-time communication, and the evaluation criteria can be set according to actual usage requirements.

The client device also includes a link evaluation module, after receiving the detection result obtained by the network detection module, it can evaluate the current link quality according to the packet loss rate, average delay value, and jitter value obtained by the link detection in the latest cycle; The current link quality can be evaluated based on the packet loss rate, average delay value, and jitter value detected by the link in the last 10 cycles (the times can also be adjusted as needed). When using the values of multiple detection periods, the step S31 includes:

Wherein, the weighting algorithm in step S311 may determine the proportion of each cycle detection value according to the weight, and then calculate a relatively accurate and reasonable final value for determining the evaluation level in step S312.

After each detection period, the network detection module saves the detection data, and the evaluation module evaluates the link. The link evaluation module calculates the weighted jitter value, packet loss rate and average delay value by taking the latest n detection results on the link according to a certain weighting method. The weighting method can be adjusted as needed. Generally speaking, the newer the The weight of the detection data should also be larger. After obtaining the weighted data, look at which level of the evaluation standard each data falls into. According to the bucket law, the worst level of the three weighted data is used as the quality level of the current link.

The calculation formula of the weighting algorithm is as follows:

.

in,

is the detection value obtained for the jth most recent time,

is the weight corresponding to the most recent jth detection, n is the total number of weighted calculations, and

is the final weighted value.

The weighting algorithm is described by taking the average delay as an example. Take n as 10, set the weight of the weighting parameter

: {1%, 1%, 2%, 3%, 5%, 5%, 8%, 10%, 20%, 45%}, that is, the weight of the newly detected data accounts for 45%, and it is pushed up for the second time The weight of the first detection is 20%, the third time is 10%, and so on, the earliest detection weight is the smallest, which is 1%.

Average latency data for the last 10 probes

: { 37.314, 36.638, 38.194, 37.900, 38.883, 37.550, 38.040, 38.162, 39.233, 36.809} (unit is ms), the weighted average delay is calculated as follows: 7.314*1%+36.638*1%+38.194*2%+ 37.900*3%+38.883*5%+37.550*5%+38.040*8%+38.162*10%+39.233*20%+36.809*45%=37.732.

After calculation, the weighted average delay of the link is 37.732ms, which belongs to the excellent level in the evaluation standard.

According to the above method, the weighted jitter value and the packet loss rate can be calculated, and it can be judged which level of the evaluation standard it falls into. Each link has the above three weighted data, and the level with the worst three weighted data is selected. As the quality level of the current link, the quality levels of all links are determined in this way.

According to the link quality level, the client device selects the optimal link as the primary link, and other links as the backup links. Specifically, step S40 includes: when one of the following situations A, B, and C is detected, according to the quality level of each link, determine that one of the links with the highest quality level is the primary link, and the others are Backup link:

A. The main link is not set in the current network;

c. The link whose quality level changes in the current network is the current main link, and the quality level of the current main link becomes lower and the network is in a busy state.

In case A, the current network is a newly established network or a rebuilt network, and no primary link is set, so the primary link and the backup link need to be selected based on the quality level of the link. In this case we choose {

} The highest link in. When two or more links with the highest quality level are selected, according to the evaluation level of the key options of the link, the link with the best evaluation level is selected as the main link, where the key options are packet loss, average One of delay and jitter. For example, if a user cares about the quality of real-time communication, jitter can be selected as a key option. When encountering multiple links with the same quality level, the link with the smallest jitter is selected as the final main link. According to this selection rule, the main link is the one with the best network conditions among all the current links.

In case B, the link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes lower and the network is unavailable, that is, the link level of the current primary link is 0, then it is necessary to immediately Select the primary link again, and determine the one with the highest quality level among the links as the primary link and the others as backup links according to the quality levels of each link. When two or more links with the highest quality level are selected, according to the evaluation level of the key options of the link, the link with the best evaluation level is selected as the main link, where the key options are packet loss, average One of delay and jitter.

In case C, the link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes lower and the network is in a busy state, that is, the level of the current link is greater than 0. According to the quality level of each link, select the one with the highest quality level among the current standby links. If the quality level of the current standby link is higher than that of the current primary link, and the bandwidth of the current standby link is greater than that of the current primary link If the bandwidth of the link is selected, the current standby link is selected as the primary link. Specifically, when situation C occurs, first look at the bandwidth ratio of the link. If the bandwidth ratio is high, it means that the link quality is degraded because the network is very busy. In this case, the bandwidth needs to be higher than the current main link. The large standby link looks for an available link. If there is a link in the standby link with a link quality level higher than that of the primary link and a larger bandwidth than the primary link, it is selected as the new primary link.

The step S40 further includes:

When it is detected that the link whose quality level has changed in the current network is the backup link, and the quality level of the current backup link becomes higher and higher than that of the current primary link

, and the current backup link satisfies that the current backup link bandwidth is greater than the current primary link bandwidth

When the conditions are met, the current standby link is selected as the primary link;

, and the current backup link satisfies that the current backup link bandwidth is less than or equal to the current primary link bandwidth

condition, and the current main link satisfies that the current main link bandwidth ratio is lower than the bandwidth ratio threshold (for example, the bandwidth ratio threshold is 30%, the current main link bandwidth ratio b is lower than 30%) and the current main link bandwidth ratio If the network traffic of the current backup link is less than the bandwidth of the current backup link, the current backup link is selected as the primary link.

The step S40 further includes:

In the above cases a, b, and c, in fact, the main link in the current network still has the highest quality level among all the links, so it is not necessary to re-select the main link. The above cases d and e are compared to determine that even if the quality level of the existing link exceeds the quality level of the current main link, if the conditions of bandwidth ratio or key options are not met in case d, the current main chain is still selected. If the conditions of bandwidth or bandwidth ratio or network traffic are not met in case e, the current primary link is still selected as the primary link.

Based on whether the network sets the primary link and the backup link, the step S50 specifically includes:

The client device further includes a link selection module, which is used to obtain the evaluation level of each link according to the link evaluation module, and select the current optimal link as the main link. The client device further includes a routing module, which sets the route of the client device according to the result of the link selection module.

The currently used link is called the main link, and the quality level of the main link is set as

, and the unused link is called the standby link, and the link quality level is {

}, there may be more than one, and the latest change link quality level is

. When the client device performs step S40, the link selection steps are as follows:

It is detected whether there is a main link in the current network. If there is no main link, the main link is selected according to the quality level of the link obtained by calculation in steps S20 and S30. The selection principle is to take all the links with the highest quality level as the primary link, and the others as the backup links. When there is more than one link with the highest link quality level, the main link is optimally determined according to the evaluation level of key options.

When detecting that there is an active link in the current network, it is necessary to detect whether the quality level changes of the active link or the standby link. If it is the main link, it needs to be judged according to the situation.

If the link level becomes higher, the link does not need to be changed; if the link level becomes lower and the link level is 0, it means that the network is unavailable, and the quality of the link needs to be calculated according to steps S20 and S30. level, immediately re-select the route, and take the link with the highest quality level as the primary link.

If the link level becomes lower, but its value is still greater than 0, first look at the bandwidth ratio of the link. If the bandwidth ratio is high, it means that the link quality is degraded because the network is very busy. The standby link whose bandwidth is larger than the current primary link searches for an available link. If there is a link in the standby link with a link quality level higher than that of the primary link and a larger bandwidth than the primary link, it is selected as the new primary link, and the route is reset. The link selection module notifies the routing module to switch routes.

If the latest changed link is the backup link and the link quality level is lower, it is not necessary to reselect the primary link.

If the latest changed link is an idle link and the link quality level is higher, it needs to be selected according to the situation.

If the quality level of the new link is lower than the quality level of the main link, there is no need to re-select the main link;

If the quality level of the new link is equal to the level of the main link, it depends on the bandwidth ratio of the main link. If the bandwidth ratio is very low (for example, the bandwidth ratio is less than 30% and the network is idle), compare the key options of the main link and the new link. If the key options of the new link are better than the main link, you need to reset the settings. route, the link selection module notifies the routing module to switch the route, and the link does not need to be switched in other cases;

If the quality level of the new link is greater than the level of the main link, compare the bandwidth of the main link and the new link. If the bandwidth of the new link is relatively large, switch the current route, otherwise, look at the bandwidth ratio of the main link. The bandwidth ratio is very low (for example, the bandwidth ratio is less than 30%, and the network is idle), and the network traffic of the main link does not exceed the bandwidth of the new link. The route needs to be reset, and the route needs to be switched. In other cases, the route is not switched.

After receiving the route switching notification from the link selection module, the route selection module deletes the route of the old link and adds a new link route to complete the link selection. If no switch is received, no need to re-route.

The intelligent link selection method based on the client device in the SD-WAN network environment under the cloud computing system provided by the present invention, through periodic active detection, evaluates the network quality level in time, intelligently selects the relatively optimal link for the network, and Fully consider the actual needs of users (such as the setting of key options). Using the weighted packet loss rate, average delay, and jitter instead of the latest link packet loss rate, average delay, and jitter will greatly reduce network oscillations. The balance of the proportion will also make the network more stable and improve the user's network experience.

It should be understood by those skilled in the art that the embodiments of the present invention shown in the above description and the accompanying drawings are only examples and do not limit the present invention. The objects of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been shown and described in the embodiments, and the embodiments of the present invention may be modified or modified in any way without departing from the principles.

Claims

A cloud computing-based SD-WAN network intelligent link selection method, applied to a client device, characterized in that the method comprises:

Step S10, establishing multiple communication links between the client device and multiple edge routers deployed in the cloud environment;

Step S20, detecting the network status of each communication link;

Step S30, evaluating the quality level of each link according to the detected network conditions;

Step S40, according to the quality level of each link, determine that one of the links with the highest quality level is the primary link, and the others are backup links;

Step S50, setting the route of the client device according to the determined primary link and backup link.
A cloud computing-based SD-WAN network intelligent link selection method according to claim 1, wherein the client device is a CPE device or a VCPE device.
A cloud computing-based SD-WAN network intelligent link selection method according to claim 1, wherein step S20 comprises:

Step S21, sends periodic detection instructions to each link to obtain the detection results of each communication link;

Step S22, according to the detection result, obtain the packet loss rate, average delay value, and jitter value of each link, and obtain the bandwidth ratio of each link.
A cloud computing-based SD-WAN network intelligent link selection method according to claim 1, wherein step S30 comprises:

Step S31, according to the detected network state, including the packet loss rate, the average delay value, and the jitter value, compare the packet loss rate evaluation standard table, the average delay value evaluation standard table, and the jitter value evaluation standard table, respectively, to determine the packet loss of each link. Evaluation level, average delay evaluation level, jitter evaluation level;

Step S32, according to the bucket law, the worst level in the packet loss evaluation level, average delay evaluation level, and jitter evaluation level in each link is used as the quality level of the link, and the quality level of all links is determined in this way. .
A cloud computing-based SD-WAN network intelligent link selection method according to claim 4, wherein the step S31 comprises:

Step S311, according to the network state of periodic detection, each link has the packet loss rate, average delay value, and jitter value of multiple periodic detections; according to the weighting algorithm, determine the weighted packet loss rate and the weighted average delay of each link. value, weighted jitter value;

Step S312, compare the packet loss rate determined by each link with the packet loss rate evaluation standard table to obtain the packet loss evaluation level of each link; compare the average delay value determined by each link with the average delay value evaluation standard table to obtain Average delay evaluation level of each link; compare the jitter value determined for each link with the jitter value evaluation standard table to obtain the jitter evaluation level of each link.
A cloud computing-based SD-WAN network intelligent link selection method according to claim 1, wherein step S40 comprises:

When one of the following conditions A, B, and C is detected, according to the quality level of each link, the one with the highest quality level among the links is determined as the primary link, and the others are standby links:

The main link is not set in the current network;

The link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes lower and the network is unavailable;

The link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes lower and the network is in a busy state.
A cloud computing-based SD-WAN network intelligent link selection method according to claim 6, wherein when there are two or more links with the highest quality level in each link, according to the link The evaluation level of the key option is selected, and the link with the optimal evaluation level is selected as the main link, where the key option is one of packet loss, average delay, and jitter.
A cloud computing-based SD-WAN network intelligent link selection method according to claim 6, wherein the situation C includes: when it is detected that the link whose quality level changes in the current network is the current main link, and When the quality level of the current active link becomes lower and the network is busy, select the one with the highest quality level among the current standby links according to the quality levels of each link. If the quality level of the current standby link is higher than that of the current active link The quality level of the link, and the bandwidth of the current backup link is greater than that of the current primary link, the current backup link is selected as the primary link.
The cloud computing-based SD-WAN network intelligent link selection method according to claim 6, wherein the step S40 further comprises: when it is detected that the link whose quality level changes in the current network is the current standby link and the quality level of the current backup link becomes higher and equal to the quality level of the current primary link, and the current primary link satisfies the condition that the bandwidth ratio of the current primary link is lower than the bandwidth ratio threshold, and the current backup link meets the condition that the bandwidth ratio of the current primary link is lower than the bandwidth ratio threshold When the evaluation level of the key option of the backup link is higher than the evaluation level of the same key option of the current primary link, the current backup link is selected as the primary link; the key options are packet loss, average delay, jitter one of the.
The cloud computing-based SD-WAN network intelligent link selection method according to claim 6, wherein the step S40 further comprises:

When it is detected that the link whose quality level has changed in the current network is a backup link, and the quality level of the current backup link becomes higher and higher than that of the current primary link, and the current backup link satisfies that the bandwidth of the current backup link is greater than that of the current backup link When the bandwidth of the primary link is satisfied, the current backup link is selected as the primary link;

When it is detected that the link whose quality level has changed in the current network is a backup link, and the quality level of the current backup link becomes higher and higher than that of the current primary link, and the current backup link satisfies that the bandwidth of the current backup link is less than or equal to The current primary link bandwidth condition, and the current primary link satisfies the condition that the current primary link bandwidth ratio is lower than the bandwidth ratio threshold and the current primary link network traffic is less than the current backup link bandwidth, select the current backup link main link.
The cloud computing-based SD-WAN network intelligent link selection method according to claim 6, wherein the step S40 further comprises:

When one of the following conditions a, b, c, d, and e is detected, it is determined that the current primary link is still the primary link:

a. The link whose quality level changes in the current network is the current primary link, and the quality level of the current primary link becomes higher;

b. The link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes lower;

c. The link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes higher and lower than the quality level of the current primary link;

d. The link whose quality level changes in the current network is the current standby link, and the quality level of the current standby link becomes higher and equal to the quality level of the current primary link, and the bandwidth ratio of the current primary link cannot be lower than the bandwidth ratio. The condition of the threshold or the evaluation level of the key option of the current standby link is better than the evaluation level of the same key option of the current main link, where the key option is one of packet loss, average delay, and jitter;

e. The link whose quality level changes in the current network is the standby link, and the quality level of the current standby link becomes higher and higher than the quality level of the current primary link, and the current standby link bandwidth is less than or equal to the current primary link bandwidth. The condition or the condition that the bandwidth ratio of the current active link is lower than the bandwidth ratio threshold or the condition that the network traffic of the current active link is less than the bandwidth of the current backup link.
The cloud computing-based SD-WAN network intelligent link selection method according to claim 6, wherein the step S50 comprises:

If the current network does not set the primary link and the backup link, set the route of the client device according to the primary link and the backup link determined in step S40;

If the current network has set the primary link and the backup link and the primary link and the backup link change, delete the original route setting, and set the route of the client device according to the primary link and the backup link re-determined in step S40.