CN113542098B

CN113542098B - Method, system, device and storage medium for establishing and switching SD-WAN tunnel

Info

Publication number: CN113542098B
Application number: CN202110790295.7A
Authority: CN
Inventors: 张届新; 张宏丙; 陈乐贤; 周其刚; 徐海峰
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2022-11-25
Anticipated expiration: 2041-07-13
Also published as: CN113542098A

Abstract

The invention provides a method, a system, equipment and a storage medium for establishing and switching an SD-WAN tunnel, wherein the method comprises the following steps: receiving first tunnel establishment/switching application information sent by a client front-end device on a main access link, wherein the first tunnel establishment/switching application information comprises a tunnel identifier and an application timestamp; acquiring tunnel information according to the tunnel identifier; sending second tunnel establishment/switching application information to the IP-SDN controller corresponding to the main access link, wherein the second tunnel establishment/switching application information comprises tunnel information and an application timestamp, so that the IP-SDN controller can select an available routing table meeting tunnel bandwidth and determine an available tunnel; and sending the available routing table of the available tunnel to the client front-end equipment so that the client front-end equipment can execute tunnel establishment/switching according to the available routing table of the available tunnel. The invention can relieve tunnel link oscillation between the main and standby access links caused by instant exhaustion of IP network resources due to simultaneous establishment/switching of a large number of tunnels in the SD-WAN network.

Description

Method, system, device and storage medium for establishing and switching SD-WAN tunnel

Technical Field

The present invention relates to the field of data communication technologies, and in particular, to a method, a system, a device, and a storage medium for establishing and switching an SD-WAN tunnel.

Background

At present, for the establishment and switching of SD-WAN (Wide area software defined network) tunnels, the routing of the underlying underlay IP network is statically configured or dynamically routed, and the right of all the tunnels for selecting IP routing is the same. On the other hand, the SD-WAN CPE (Customer Premise Equipment) generally accesses the SD-WAN Network through a plurality of different access networks (such as a PON (Passive Optical Network) access Network, an IPRAN (radio access Network IP), and the like), and the two access modes are set to be the active/standby switching mode.

The background art is described below with reference to fig. 1 to 3. In fig. 1 and fig. 2, thin solid line connecting lines indicate that an IP between devices is reachable, thick solid line connecting lines indicate physical active access links, dotted line connecting lines indicate physical standby access links, and dot-dash lines indicate the directions of tunnels and service flows. Wherein, an IP-SDN (Software Defined Network) controller A40, an IP-SDN controller B40 and an SD-WAN controller 20 belong to the control layer 1; the IP network 31 belongs to an underlay IP network; the mobile IP network 32 belongs to the mobile IP network layer; the client front-end device a10 and the client front-end device B10 belong to the client front-end device layer 3. The devices interact according to the steps shown in fig. 3:

step S1: the client front-end device a10 transmits registration request information including the serial number of the client front-end device a10 to the SD-WAN controller 20.

Step S2: the SD-WAN controller 20 determines that the client front-end device a10 is legitimate by comparing the serial number of the client front-end device a10 with the work order, and acquires tunnel information associated with the serial number of the client front-end device a 10.

And step S3: the SD-WAN controller 20 returns a registration success request to the client pre-device a10, and issues a routing table according to the tunnel information.

And step S4: the client front-end device A10 establishes a tunnel in the IP network on the main access link according to the routing table;

step S5: the client premise equipment a10 successfully establishes the tunnel and communicates with the client premise equipment B10.

Step S6: tunnel establishment fails or it is detected that the established tunnel quality parameter is within a degradation threshold.

Step S7: the client front-end device a10 switches to the standby access link.

Step S8: the client front-end device a10 establishes a tunnel within the IP network over the backup access link according to the routing table.

Step S9: the client premise equipment a10 successfully establishes the tunnel and communicates with the client premise equipment B10.

Step S10: tunnel establishment fails or it is detected that the established tunnel quality parameter is within a degradation threshold.

Step S11: the client front-end device a10 switches to the primary access link, and establishes an IPSec (Internet Protocol Security) tunnel.

By the above method, when the CPE monitors that a tunnel cannot be established or the quality of the established tunnel (packet loss, delay or jitter increase) is degraded to a set threshold, the CPE automatically switches the access mode from the active mode (e.g., PON optical network) to the standby access network mode (e.g., IPRAN), i.e., realizes "hard route" switching to ensure the quality of the SD-WAN tunnel. However, in addition to the physical access method, which affects the quality of the tunnel, in many cases, it is much more the underlying underlay network quality. Therefore, when the CPE cannot establish a tunnel or monitors that the quality of a certain tunnel deteriorates to a threshold value, even by automatically switching the physical access mode, if the corresponding IP network is congested at this time or a large number of tunnels are simultaneously switched to the originally relatively idle underlay network route in the tunnel switching process, the tunnel is failed to be switched, so that the tunnel is switched between the active access mode and the standby access mode without stopping, which causes link oscillation.

Therefore, it is a technical problem to be urgently solved by technical personnel in the field how to relieve the oscillation of a large number of tunnel links between a main access link and a standby access link caused by the instant exhaustion of IP network resources due to the simultaneous establishment/switching of a large number of tunnels in an SD-WAN network, so as to improve user experience.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the invention and therefore may include information that does not constitute prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

The invention aims to provide a method, a system, equipment and a storage medium for establishing and switching an SD-WAN tunnel, overcomes the difficulty in the prior art, and relieves the vibration of a large number of tunnel links between main and standby access links caused by the instant exhaustion of IP network resources due to the simultaneous establishment/switching of a large number of tunnels in an SD-WAN network, thereby improving the user experience.

The embodiment of the invention provides a method for establishing and switching an SD-WAN tunnel, which comprises the following steps:

receiving first tunnel establishment/switching application information sent by a client front-end device on a main access link, wherein the first tunnel establishment/switching application information comprises a tunnel identifier and an application timestamp;

acquiring tunnel information according to the tunnel identifier, wherein the tunnel information comprises tunnel address information, tunnel bandwidth and tunnel priority;

sending second tunnel establishment/handover application information to an IP-SDN controller corresponding to a primary access link, wherein the second tunnel establishment/handover application information comprises the tunnel information and an application timestamp, so that the IP-SDN controller corresponding to the primary access link determines a link calculation order of the second tunnel establishment/handover application information according to the application timestamp and/or a tunnel priority and sequentially selects an available routing table meeting the tunnel bandwidth according to the link calculation order and determines an available tunnel according to a plurality of pieces of tunnel establishment/handover application information received within a set time period;

and sending the available routing table of the available tunnel to the client front-end equipment so that the client front-end equipment can execute tunnel establishment/switching on the main access link according to the available routing table of the available tunnel.

In some embodiments of the present invention, before the receiving the first tunnel establishment/handover application information sent by the client front-end device on the active access link, the method further includes:

receiving registration request information of the client front-end equipment, wherein the registration request information comprises a tunnel identifier and a tunnel priority;

storing the tunnel identifier and the tunnel priority;

and sending registration success feedback information to the client front-end equipment.

In some embodiments of the present invention, the registration request information further includes a terminal serial number of the client front-end device, and before storing the tunnel identifier and the tunnel priority, further includes:

matching the terminal serial number of the client front-end equipment with a work order to judge whether the client front-end equipment is a legal terminal;

if yes, tunnel address information and tunnel bandwidth related to the tunnel identifier are obtained from the work order;

the storing the tunnel identifier and the tunnel priority further comprises:

and storing the tunnel address information and the tunnel bandwidth.

In some embodiments of the present invention, the first tunnel establishment/handover application information is generated based on one or more of the following triggers:

the customer premises equipment fails to establish/switch the tunnel based on the standby access link;

the quality parameter of the established tunnel of the customer premise equipment based on the standby access link is positioned in a range of a degradation setting threshold;

the client front-end equipment establishes a tunnel for the first time.

In some embodiments of the present invention, the determining a link calculation order of the second tunnel establishment/handover application information according to the application timestamp and/or the tunnel priority includes:

determining a quasi-link calculation sequence of the second tunnel establishment/switching application information according to the tunnel priority from high to low;

judging whether a plurality of second tunnel establishment/switching application information with the same tunnel priority exists in the quasi link calculation sequence;

if yes, sequencing and adjusting the tunnel establishment/switching application information with the same tunnel priority in the quasi-link calculation sequence according to the application time stamps from early to late to obtain the link calculation sequence.

In some embodiments of the invention, further comprising:

receiving third tunnel establishment/switching application information sent by the client front-end equipment on a standby access link, wherein the third tunnel establishment/switching application information comprises a tunnel identifier and an application timestamp;

sending fourth tunnel establishment/switching application information to an IP-SDN controller corresponding to a standby access link, wherein the fourth tunnel establishment/switching application information comprises the tunnel information and an application timestamp, so that the IP-SDN controller corresponding to the standby access link determines a link calculation sequence of the fourth tunnel establishment/switching application information according to the application timestamp and/or a tunnel priority and sequentially selects an available routing table meeting the tunnel bandwidth according to the link calculation sequence and determines an available tunnel according to a plurality of pieces of tunnel establishment/switching application information received in a set time period;

and sending the available routing table of the available tunnel to the client front-end equipment so that the client front-end equipment can execute tunnel establishment/switching on a standby access link according to the available routing table of the available tunnel.

In some embodiments of the present invention, the third tunnel establishment/handover application information is generated based on one or more of the following triggers:

the customer premise equipment fails to establish/switch the tunnel based on the main access link;

the quality parameters of the established tunnel of the customer premise equipment based on the main access link are positioned in the range of the degradation setting threshold.

According to another aspect of the present invention, there is also provided an apparatus for establishing and switching an SD-WAN tunnel, applied to an SD-WAN controller, including:

a first receiving module, configured to receive first tunnel establishment/handover application information sent by a client front-end device on a primary access link, where the first tunnel establishment/handover application information includes a tunnel identifier and an application timestamp;

a first obtaining module configured to obtain tunnel information according to the tunnel identifier, where the tunnel information includes tunnel address information, tunnel bandwidth, and tunnel priority;

a first sending module, configured to send second tunnel establishment/handover application information to an IP-SDN controller corresponding to a primary access link, where the second tunnel establishment/handover application information includes the tunnel information and an application timestamp, so that the IP-SDN controller corresponding to the primary access link determines, according to the application timestamp and/or a tunnel priority, a link calculation order of the second tunnel establishment/handover application information according to a plurality of pieces of tunnel establishment/handover application information received within a set time period, sequentially selects an available routing table that satisfies a tunnel bandwidth according to the link calculation order, and determines an available tunnel;

a second sending module, configured to send the available routing table of the available tunnel to the client pre-device, so that the client pre-device performs tunnel establishment/handover on the active access link according to the available routing table of the available tunnel.

According to another aspect of the present invention, there is also provided a system for establishing and switching an SD-WAN tunnel, including:

an SD-WAN controller configured to perform the steps of:

sending second tunnel establishment/switching application information to a first IP-SDN controller corresponding to a main access link, wherein the second tunnel establishment/switching application information comprises the tunnel information and an application timestamp, and receiving an available routing table of an available tunnel sent by the first IP-SDN controller;

sending the available routing table of the available tunnel to the client front-end device, so that the client front-end device can execute tunnel establishment/switching on the main access link according to the available routing table of the available tunnel;

a first IP-SDN controller configured to perform the steps of:

determining a link calculation order of the second tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority according to the received multiple pieces of tunnel establishment/switching application information in a set time period;

and sequentially selecting available routing tables meeting the tunnel bandwidth according to the link calculation sequence, and determining available tunnels.

In some embodiments of the invention, the SD-WAN controller is further configured to perform the steps of:

sending fourth tunnel establishment/switching application information to a second IP-SDN controller corresponding to a standby access link, wherein the fourth tunnel establishment/switching application information comprises the tunnel information and an application timestamp, and receiving an available routing table of an available tunnel sent by the second IP-SDN controller;

sending the available routing table of the available tunnel to the client front-end device for the client front-end device to perform tunnel establishment/switching on a standby access link according to the available routing table of the available tunnel,

the system for establishing and switching the SD-WAN tunnel further comprises:

a second IP-SDN controller configured to perform the steps of:

determining a link calculation order of the fourth tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority according to the received multiple tunnel establishment/switching application information in a set time period;

In some embodiments of the invention, further comprising:

a client premises equipment configured to perform the steps of:

the first tunnel establishment/switching application information sent on the main access link or the third tunnel establishment/switching application information sent on the standby access link;

and executing tunnel establishment/switching on the main access link or the standby access link according to the received available routing table of the available tunnel.

According to yet another aspect of the present invention, there is also provided an IP-SDN controller configured to perform the steps of:

receiving tunnel establishment/switching application information sent by an SD-WAN controller, wherein the tunnel establishment/switching application information comprises tunnel information and an application timestamp, and the tunnel information comprises tunnel priority and tunnel bandwidth;

determining a link calculation order of the tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority according to a plurality of pieces of tunnel establishment/switching application information received in a set time period;

sequentially selecting available routing tables meeting the tunnel bandwidth according to the link calculation sequence, and determining available tunnels;

and sending the available routing table of the available tunnel to the SD-WAN controller so that the client front-end equipment can perform tunnel establishment/switching according to the available routing table of the available tunnel.

The embodiment of the invention also provides a device for establishing and switching the SD-WAN tunnel, which comprises the following steps:

a processor;

a memory having stored therein executable instructions of the processor;

wherein the processor is configured to perform the steps of the above method of establishing and switching an SD-WAN tunnel by executing the executable instructions.

Embodiments of the present invention also provide a computer-readable storage medium for storing a program, which when executed, implements the steps of the above-described method of establishing and switching an SD-WAN tunnel.

Compared with the prior art, the invention aims to:

the invention can relieve a large amount of tunnel link oscillation between the main and standby access links caused by instant exhaustion of IP network resources due to simultaneous establishment/switching of a large amount of tunnels in the SD-WAN network, thereby improving user experience.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings.

FIG. 1 is a block diagram of a background art system for establishing and switching SD-WAN tunnels;

FIG. 2 is a diagram of a background art networking for establishing and switching SD-WAN tunnels;

fig. 3 is a timing diagram of a method of establishing and switching an SD-WAN tunnel of the background art;

fig. 4 is a flow chart of one embodiment of a method of establishing and switching SD-WAN tunnels of the present invention.

Fig. 5 is a flow diagram of another embodiment of a method of establishing and switching SD-WAN tunnels of the present invention.

FIG. 6 is a block diagram of a system for establishing and switching SD-WAN tunnels of the present invention;

FIG. 7 is a schematic networking diagram of the invention for establishing and switching SD-WAN tunnels;

fig. 8 is a timing diagram of the method of establishing and switching SD-WAN tunnels of the present invention;

FIG. 9 is a block diagram illustrating one embodiment of a system for establishing and switching SD-WAN tunnels in accordance with the present invention;

fig. 10 is a block diagram of another embodiment of the system for establishing and switching SD-WAN tunnels of the present invention;

fig. 11 is a schematic structural diagram of the device for establishing and switching the SD-WAN tunnel according to the present invention.

Fig. 12 is a schematic structural diagram of a computer-readable storage medium according to an embodiment of the present invention.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their repetitive description will be omitted.

Fig. 4 is a flow chart of one embodiment of a method of establishing and switching SD-WAN tunnels of the present invention. The embodiment of the invention provides a method for establishing and switching an SD-WAN tunnel, which comprises the following steps:

step S110: and receiving first tunnel establishment/switching application information sent by the client front-end equipment on the main access link.

Specifically, the first tunnel establishment/handover application information may include a tunnel identifier and an application timestamp.

Specifically, the first tunnel establishment/handover application information may be triggered according to a tunnel establishment/handover failure of the ue based on the backup access link. In some variations, the first tunnel establishment/handover application information may also be triggered according to that the quality parameter of the established tunnel of the backup access link is within a threshold range set by the ue. The quality parameters of the established tunnel may include, for example, packet loss rate, delay or jitter increase degree, etc. In other variations, the first tunnel establishment/handover application information may be triggered according to the first tunnel establishment of the ue front-end device. The invention is not so limited.

Step S120: and acquiring tunnel information according to the tunnel identifier.

Specifically, the tunnel information includes tunnel address information, tunnel bandwidth, and tunnel priority. The tunnel address information includes tunnel source address information and tunnel destination address information.

Step S130: and sending the second tunnel establishment/switching application information to the IP-SDN controller corresponding to the main access link.

Specifically, the second tunnel establishment/handover application information includes the tunnel information and an application timestamp. And the second tunnel establishment/switching application information is used for an IP-SDN controller corresponding to the main access link to determine a link calculation sequence of the second tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority and to sequentially select an available routing table meeting the tunnel bandwidth according to the link calculation sequence and determine an available tunnel according to a plurality of pieces of tunnel establishment/switching application information received in a set time period. Specifically, the IP-SDN controller may receive multiple pieces of tunnel establishment/handover application information within a set time period, and the received tunnel establishment/handover application information may include second tunnel establishment/handover application information, which is not limited in the present invention.

Step S140: and sending the available routing table of the available tunnel to the client front-end equipment.

Specifically, in step S140, the ue performs tunnel establishment/handover on the active access link according to the available routing table of the available tunnel.

Compared with the prior art, the method for establishing and switching the SD-WAN tunnel can relieve a large amount of tunnel link oscillation between the main access link and the standby access link caused by instant exhaustion of IP network resources due to simultaneous establishment/switching of a large amount of tunnels in the SD-WAN network, thereby improving user experience.

Fig. 2 is a flow diagram of another embodiment of the method of establishing and switching SD-WAN tunnels of the present invention. As shown in fig. 2, the method for establishing and switching SD-WAN tunnels further includes steps S101 to S104 and S151 to S156 on the basis of steps S110 to S140 in the embodiment of fig. 1, and the following steps are described one by one according to the order of steps.

Step S101: and receiving registration request information of the client front-end equipment, wherein the registration request information comprises a tunnel identifier and a tunnel priority.

Step S102: and matching the terminal serial number of the client front-end equipment with a work order to judge whether the client front-end equipment is a legal terminal.

If the determination in step S102 is yes, step S103 is executed: and acquiring tunnel address information and tunnel bandwidth related to the tunnel identifier from the work order.

Step S104: and storing the tunnel identifier, the tunnel priority, the tunnel address information and the tunnel bandwidth, and sending registration success feedback information to the client front-end equipment.

Step S120: and acquiring tunnel information according to the tunnel identifier.

Specifically, because of the storage of the tunnel identifier and the tunnel information association, step S120 may obtain the tunnel information according to the tunnel identifier. The tunnel information includes tunnel address information, tunnel bandwidth, and tunnel priority. The tunnel address information includes tunnel source address information and tunnel destination address information.

Specifically, the second tunnel establishment/handover application information includes the tunnel information and an application timestamp. And the second tunnel establishment/switching application information is used for the IP-SDN controller corresponding to the main access link to determine the link calculation order of the second tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority and the application timestamp and/or the tunnel priority according to a plurality of pieces of tunnel establishment/switching application information received in a set time period, sequentially select an available routing table meeting the tunnel bandwidth according to the link calculation order and determine an available tunnel.

Specifically, an IP-SDN controller corresponding to the active access link determines a link calculation order according to the following manner: determining a quasi-link calculation order of the second tunnel establishment/switching application information according to the tunnel priority from high to low; judging whether a plurality of pieces of tunnel establishment/switching application information with the same tunnel priority exist in the quasi link calculation sequence; if yes, sequencing and adjusting the tunnel establishment/switching application information with the same tunnel priority in the quasi-link calculation sequence according to the application time stamps from early to late to obtain the link calculation sequence.

Step S151: the client front-end device fails to establish/switch the tunnel based on the main access link or the quality parameter of the established tunnel based on the main access link of the client front-end device is within the range of the degradation setting threshold.

Step S152: and receiving third tunnel establishment/switching application information sent by the client front-end equipment on a standby access link.

Specifically, the third tunnel establishment/handover application information includes a tunnel identifier and an application timestamp.

Step S153: and acquiring tunnel information according to the tunnel identifier.

Specifically, because of the storage of the tunnel identifier and the tunnel information association, step S153 may acquire the tunnel information according to the tunnel identifier. The tunnel information includes tunnel address information, tunnel bandwidth, and tunnel priority. The tunnel address information includes tunnel source address information and tunnel destination address information.

Step S154: and sending the fourth tunnel establishment/switching application information to an IP-SDN controller corresponding to the standby access link.

Specifically, the fourth tunnel establishment/handover application information includes the tunnel information and an application timestamp, so that an IP-SDN controller corresponding to the standby access link determines a link calculation order of the fourth tunnel establishment/handover application information according to the application timestamp and/or a tunnel priority according to a plurality of pieces of tunnel establishment/handover application information received within a set time period, sequentially selects an available routing table satisfying the tunnel bandwidth according to the link calculation order, and determines an available tunnel. Specifically, the IP-SDN controller may receive multiple pieces of tunnel establishment/handover application information within a set time period, and the received tunnel establishment/handover application information may include fourth tunnel establishment/handover application information, which is not limited in the present invention.

The IP-SDN controller corresponding to the standby access link may determine the link calculation order in the same manner as the IP-SDN controller corresponding to the active access link.

Step S155: and sending the available routing table of the available tunnel to the client front-end equipment so that the client front-end equipment can execute tunnel establishment/switching on a standby access link according to the available routing table of the available tunnel.

Step S156: the quality parameter of the tunnel established/switched by the customer premises equipment based on the standby access link is within the range of the degradation setting threshold value.

Specifically, after step S156, step S110 may be executed again to implement switching of the main/standby access links.

Further, fig. 5 shows a specific implementation manner of the present invention, and the combination, the division, and the change of the execution sequence of the steps are all within the protection scope of the present invention.

Referring now to fig. 6-8, fig. 6 is a block diagram of the system for establishing and switching SD-WAN tunnels of the present invention; FIG. 7 is a schematic networking diagram of the invention for establishing and switching SD-WAN tunnels;

fig. 8 is a timing diagram of the method of establishing and handing off an SD-WAN tunnel of the present invention. Fig. 6 to 8 are merely schematic, and variations in the number of devices and communication methods are within the scope of the present invention.

In fig. 6 and 7, the thin solid line connecting line indicates that the IP between the devices is reachable, the thick solid line connecting line indicates the physical active access link, the dotted line connecting line indicates the physical standby access link, and the dash-dot line indicates the direction of the tunnel and the traffic flow. Wherein an IP-SDN (Software Defined Network) controller a41, an IP-SDN controller B41, and an SD-WAN controller 21 belong to the control layer 1; the IP network 31 belongs to an underlay IP network; the mobile IP network 32 belongs to the mobile IP network layer; the client front-end device a11 and the client front-end device B11 belong to the client front-end device layer 3. The system for establishing and switching the SD-WAN tunnel may include an IP-SDN controller a41 and an SD-WAN controller 21. Further, the system for establishing and switching the SD-WAN tunnel may further include an IP-SDN controller B41, a client front-end device a11, and a client front-end device B11. The devices may interact with each other according to the steps shown in fig. 8.

Step S12: the client front-end device a11 transmits registration request information to the SD-WAN controller 21. The registration request information includes a tunnel identifier and a tunnel priority.

Step S13: the SD-WAN controller 21 matches the terminal serial number of the client front-end device with a work order to judge whether the client front-end device is a legal terminal, acquires tunnel address information and tunnel bandwidth related to the tunnel identifier from the work order if the client front-end device is a legal terminal, and stores the tunnel identifier, the tunnel priority, the tunnel address information and the tunnel bandwidth

Step S14: the SD-WAN controller 21 transmits registration success feedback information to the client front-end device a11.

Step S15: the client pre-device a11 sends first tunnel establishment/handover application information to the SD-WAN controller 21 over the primary access link. The first tunnel establishment/handover application information may include a tunnel identification and an application timestamp.

Step S16: the SD-WAN controller 21 sends the second tunnel establishment/handover application information to the IP-SDN controller a41 corresponding to the primary access link. Wherein the second tunnel establishment/handover application information includes the tunnel information and an application timestamp. And the tunnel information is obtained according to the tunnel identifier.

Step S17: the IP-SDN controller a41 determines, according to multiple pieces of tunnel establishment/handover application information received within a set time period, a link calculation order of the second tunnel establishment/handover application information according to the application timestamps and/or tunnel priorities, sequentially selects an available routing table satisfying the tunnel bandwidth according to the link calculation order, and determines an available tunnel.

Step S18: the IP-SDN controller a41 sends the available routing table of the available tunnel to the SD-WAN controller 21.

Step S19: the SD-WAN controller 21 transmits the available routing table of the available tunnel to the client premise equipment a11.

Step S20: the client front-end device a11 performs tunnel establishment/handover on the active access link according to the available routing table of the available tunnel. The tunnel is successfully established, and the client pre-device a11 communicates with the client pre-device B11.

Step S21: the client front-end device a11 fails to establish/switch the tunnel based on the active access link or the quality parameter of the established tunnel of the client front-end device a11 based on the active access link is within the range of the degradation setting threshold.

Step S22: the customer premises equipment a11 switches to the standby access link.

Step S23: the client front-end device a11 transmits the third tunnel establishment/switching application information to the SD-WAN controller 21 over the backup access link. The third tunnel establishment/handover application information includes a tunnel identifier and an application timestamp.

Step S24: the SD-WAN controller 21 transmits the fourth tunnel establishment/handover application information to the IP-SDN controller B41 corresponding to the backup access link. Wherein the fourth tunnel establishment/handover application information includes the tunnel information and an application timestamp. And the tunnel information is obtained according to the tunnel identifier.

Step S25: and the IP-SDN controller B41 determines a link calculation order of the fourth tunnel establishment/switching application information according to the application timestamps and/or the tunnel priorities and determines available tunnels according to the link calculation order by using the received multiple tunnel establishment/switching application information in a set time period.

Step S26: the IP-SDN controller B41 sends the available routing table of the available tunnel to the SD-WAN controller 21.

Step S27: the SD-WAN controller 21 transmits the available routing table of the available tunnel to the client pre-appliance a11.

Step S28: the client pre-device a11 performs tunnel establishment/switching on the backup access link according to the available routing table of the available tunnel. The tunnel is successfully established, and the client pre-device a11 communicates with the client pre-device B11.

Step S29: the quality parameter of the tunnel established by the client front-end device a11 based on the backup access link or the quality parameter of the tunnel established by the client front-end device a11 based on the backup access link is within the degradation setting threshold range.

Step S30: the customer premises equipment a11 is switched to the active access link. And step S15 to step S21 are performed again.

The above description is only illustrative of specific implementations of the present invention, and the present invention is not limited thereto, and the steps of splitting, merging, changing the execution sequence, splitting, merging, and information transmission are all within the protection scope of the present invention.

Therefore, the invention can add a tunnel priority identification module and a tunnel application timestamp module in the client front-end equipment, add a tunnel priority field and a tunnel application timestamp field in a tunnel information module of the SD-WAN controller and a communication module with the IP-SDN controller, and add a communication module with the SD-WAN controller in the IP-SDN controller to realize the time sequence steps.

When the client front-end equipment registers to the SD-WAN controller for the first time, the tunnel identifier and the tunnel priority are added to the sending information on the basis of the terminal serial number of the existing client front-end equipment. After receiving the registration information of the client front-end equipment, the SD-WAN controller compares the serial number of the terminal with the work order, and if the client front-end equipment is confirmed to be a legal terminal, the SD-WAN controller stores the tunnel identifier and the tunnel priority in the registration information, as well as the tunnel bandwidth, the source address, the destination address and the like in the work order into an information base of the tunnel.

When the client front-end equipment initiates a tunnel establishment application or monitors that the quality (packet loss, time delay or jitter increase) of a certain tunnel is degraded to a set threshold value, the client front-end equipment sends a tunnel establishment/switching application to the SD-WAN controller. And the SD-WAN controller sends information such as tunnel identification, tunnel source address, destination address, tunnel priority, tunnel bandwidth, application timestamp and the like with the establishment/handover request to an IP-SDN controller (such as an IP-SDN controller of an underlay layer IP network). The IP-SDN controller judges and selects an idle available IP route which can meet the requirement of tunnel bandwidth in real time according to a plurality of pieces of tunnel information received by a set time period delta T (the duration of the delta T can be equipment as required) and the sequence of the tunnel priority from high to low and the link initiation application time T from small (early) to large (late), thereby determining the tunnel which can be established/switched at this time. The results are then returned to the SD-WAN controller. And the SD-WAN controller issues the tunnel routing table which can be established/switched to corresponding client front-end equipment, and the client front-end equipment completes tunnel establishment/switching according to the received routing table. When monitoring that the quality of a tunnel which cannot be established at this time or the CPE is degraded to a set threshold value, automatically switching to a standby physical access mode, namely performing hard switching, and then restarting a tunnel establishment/switching application. In the underlay IP network corresponding to the standby access mode, the establishment and switching of the 'soft route' can be the same as the primary access mode.

Specifically, compared to the client front-end device a10, the client front-end device B10, the SD-WAN controller 20, the IP-SDN controller a40, and the IP-SDN controller B40 in fig. 1 and fig. 2, in this embodiment, the network elements such as the client front-end device a11, the client front-end device B11, the SD-WAN controller 21, the IP-SDN controller a41, and the IP-SDN controller B41 may implement the foregoing sequential steps by respectively adding new functional modules:

client front-end device a11, client front-end device B11:

a tunnel information identification module can be added, and information such as tunnel identification, tunnel priority, tunnel establishment/switching application timestamp t and the like is added in the tunnel information identification module.

Therefore, the client front-end device a11 and the client front-end device B11 can apply tunnel establishment/switching to send all information to the SD-WAN controller 21, and further transmit the information to the underlay IP-SDN controller a41 and the underlay IP-SDN controller B41 through the SD-WAN controller 21, so as to calculate an available IP route of a tunnel, and simultaneously receive the tunnel route table returned by the SD-WAN controller.

SD-WAN controller 21:

tunnel identification, tunnel priority, tunnel establishment/handover application timestamp fields of the client premises equipment may be added in the tunnel information base of the SD-WAN controller 21, and stored in the information base together with fields of tunnel bandwidth, tunnel source address, destination address, etc. as all information of the tunnel.

The SD-WAN controller 21 may add a communication module communicating with the IP-SDN controller a41 and the IP-SDN controller B41 of each underlay, thereby transmitting all information initiating establishment/switching of the application tunnel to the IP-SDN controller a41 and the IP-SDN controller B41 of each underlay, receiving a tunnel routing result calculated by the IP-SDN controller a41 and the IP-SDN controller B41 of each underlay, and issuing the tunnel routing result to the client front-end device corresponding to the relevant tunnel.

IP-SDN controller a41, IP-SDN controller B41 (including but not limited to various underlay IP-SDN controllers such as IP-SDN controller, mobile IP-SDN controller, etc.):

the IP-SDN controller a41 and the IP-SDN controller B41 may add a communication module communicating with the SD-WAN controller 21, receive tunnel information applied for establishment/handover from the SD-WAN controller 21, and return a tunnel route calculation result to the SD-WAN controller 21.

The IP-SDN controller a41 and the IP-SDN controller B41 may add a function module for applying for establishment/switching of tunnel information and a module for determining an available route based on the tunnel information, so that it may determine which tunnels may be successfully established/switched in a specified time period based on the tunnel information, the current network IP network route, and bandwidth resource conditions thereof, and return a determination result to the SD-WAN controller.

Therefore, in the background art, when the SD-WAN cannot be established or the CPE gateway monitors that the quality of the tunnel deteriorates to a threshold value, different physical access modes (different underlay IP networks that are uplinked) are directly switched, and a large number of links are simultaneously established or switched to instantaneously consume the routing bandwidth resources of the underlay IP network, so that a part of tunnels cannot be established or successfully switched, and finally tunnel oscillation is caused.

According to the invention, through optimizing the functional modules and the flow of the SD-WAN CPE, the SD-WAN controller and various underlay IP-SDN controllers respectively, when the CPE needs to communicate or monitors that the quality (packet loss, time delay or jitter increase) of a certain tunnel is degraded to a set threshold value, an underlay IP network is newly added for soft switching on the basis of the existing access mode of hard switching, so that the tunnel can be stably established/switched as many as possible, and tunnel oscillation is avoided. Not only improves the customer experience, but also realizes more effective utilization of network resources of operators.

The invention is cooperated by the CPE, the SD-WAN controller and the underlay IP-SDN controller, judges the tunnels which can be established or switched within the set time based on the tunnel priority, the application time stamp initiating and other comprehensive information and combines the underlay IP network routing and the bandwidth resource condition, and transmits the result to the corresponding CPE through the SD-WAN controller, thereby establishing/switching the tunnels in real time.

Compared with the prior patent, has the following advantages;

1) Closely related to the tunnel priority, guarantee the tunnel of the high priority is set up/switched over preferentially;

2) Closely related to the tunnel establishment/handover application initiation time t. Under the condition that the resource of an underlay IP network is short and the user importance level/the tunnel priority are the same, in a specified set time period, the tunnel which initiates tunnel establishment/switching at the earliest, namely the tunnel application with the minimum timestamp t, can be established/switched preferentially;

3) The CPE, SD-WAN controller and underlay IP-SDN controller cooperate closely.

4) Not only aiming at individual tunnel establishment or switching requirements every time, but also considering all the tunnel establishment/switching requirements in a set time period, considering all the tunnel establishment/switching requirements in the set time period, and ensuring tunnel establishment/switching as much as possible according to the tunnel priority and the application timestamp. Therefore, the situation that a large amount of instant demands for selecting the route are inrush to exhaust resources, and high-priority tunnels corresponding to a large number of important clients cannot be established/switched is avoided.

5) The problem that the existing network can only carry out hard switching in different access modes without comprehensively considering the tunnel oscillation caused by the tunnel switching back and forth caused by the overall routing and bandwidth availability of the underlay network is solved.

Fig. 9 is a block diagram of an embodiment of the device for establishing and switching SD-WAN tunnels according to the present invention. The device 200 for establishing and switching SD-WAN tunnels of the present invention is applied to a SD-WAN controller, as shown in fig. 9, including but not limited to:

the first receiving module 210 is configured to receive first tunnel establishment/handover application information sent by a client front-end device on an active access link, where the first tunnel establishment/handover application information includes a tunnel identifier and an application timestamp.

The first obtaining module 220 is configured to obtain tunnel information according to the tunnel identifier, where the tunnel information includes tunnel address information, tunnel bandwidth, and tunnel priority.

The first sending module 230 is configured to send second tunnel establishment/handover application information to the IP-SDN controller corresponding to the active access link, where the second tunnel establishment/handover application information includes the tunnel information and an application timestamp, so that the IP-SDN controller corresponding to the active access link determines, according to the application timestamp and/or a tunnel priority, a link calculation order of the second tunnel establishment/handover application information, sequentially selects an available routing table that satisfies the tunnel bandwidth according to the link calculation order, and determines an available tunnel according to a plurality of pieces of tunnel establishment/handover application information received within a set time period.

The second sending module 240 is configured to send the available routing table of the available tunnel to the client pre-device, so that the client pre-device performs tunnel establishment/handover on the active access link according to the available routing table of the available tunnel.

The implementation principle of the above modules is described in the method for establishing and switching the SD-WAN tunnel, and is not described herein again.

The device for establishing and switching the SD-WAN tunnel can relieve a large amount of tunnel link oscillation between the main access link and the standby access link caused by instant exhaustion of IP network resources due to simultaneous establishment/switching of a large amount of tunnels in the SD-WAN network, thereby improving user experience.

Fig. 10 is a block diagram of another embodiment of the apparatus for establishing and switching an SD-WAN tunnel according to the present invention. As shown in fig. 10, based on the embodiment of the apparatus shown in fig. 9, the apparatus 200' for establishing and switching SD-WAN tunnels according to the present invention includes, but is not limited to:

the registration receiving module 201 is configured to receive registration request information of the client front-end device, where the registration request information includes a tunnel identifier and a tunnel priority.

The determining module 202 is configured to match the terminal serial number of the client front-end device with the work order to determine whether the client front-end device is a legal terminal.

The second obtaining module 203 is configured to obtain the tunnel address information and the tunnel bandwidth associated with the tunnel identifier from the work order when the determining module 202 determines that the work order is yes.

The storage module 204 is configured to store the tunnel identifier, the tunnel priority, the tunnel address information, and the tunnel bandwidth, and send registration success feedback information to the client front-end device.

The first receiving module 210 is configured to receive first tunnel establishment/handover application information sent by the client front-end device on the active access link.

The first obtaining module 220 is configured to obtain the tunnel information according to the tunnel identifier.

The first sending module 230 is configured to send the second tunnel establishment/handover application information to the IP-SDN controller corresponding to the active access link.

The second sending module 240 is configured to send an available routing table of the available tunnel to the client premises equipment.

The first handover determining module 251 is configured to determine that the tunnel establishment/handover of the client front-end device based on the active access link fails or that a quality parameter of an established tunnel of the client front-end device based on the active access link is within a degradation setting threshold range.

The second receiving module 252 is configured to receive the third tunnel setup/switch application information sent by the client front-end device on the standby access link.

The second obtaining module 253 is configured to obtain the tunnel information according to the tunnel identifier.

The third sending module 254 is configured to send the fourth tunnel establishment/handover application information to the IP-SDN controller corresponding to the standby access link.

The fourth sending module 255 is configured to send the available routing table of the available tunnel to the client front-end device, so that the client front-end device performs tunnel establishment/switching on a standby access link according to the available routing table of the available tunnel.

The second handover determining module 256 determines that the tunnel establishment/handover of the ue based on the standby access link fails or that the quality parameter of the established tunnel of the ue based on the standby access link is within the threshold range of the degradation setting.

Fig. 9 and 10 are only schematic diagrams respectively showing the device 200 and 200' for establishing and switching SD-WAN tunnels provided by the present invention, and the splitting, merging and adding of modules are within the protection scope of the present invention without departing from the concept of the present invention. The system 200 and 200' for establishing and switching SD-WAN devices provided by the present invention can be implemented by software, hardware, firmware, plug-in and any combination thereof, and the present invention is not limited thereto.

An embodiment of the present invention further provides an IP-SDN controller, configured to execute the following steps: receiving tunnel establishment/switching application information sent by an SD-WAN controller, wherein the tunnel establishment/switching application information comprises tunnel information and an application timestamp, and the tunnel information comprises tunnel priority and tunnel bandwidth; determining a link calculation order of the tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority according to a plurality of pieces of tunnel establishment/switching application information received in a set time period; sequentially selecting available routing tables meeting the tunnel bandwidth according to the link calculation sequence, and determining available tunnels; and sending the available routing table of the available tunnel to the SD-WAN controller so that the client front-end equipment can perform tunnel establishment/switching according to the available routing table of the available tunnel.

The embodiment of the invention also provides a device for establishing and switching the SD-WAN tunnel, which comprises a processor. A memory having stored therein executable instructions of the processor. Wherein the processor is configured to perform the steps of the method of establishing and switching an SD-WAN tunnel by executing the executable instructions.

As shown above, the system for establishing and switching SD-WAN tunnels according to the embodiment of the present invention can alleviate a large amount of tunnel link oscillations between the main and standby access links caused by the instantaneous exhaustion of IP network resources due to the simultaneous establishment/switching of a large number of tunnels in the SD-WAN network, thereby improving user experience.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or program product. Thus, various aspects of the invention may be embodied in the form of: an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects that may all generally be referred to herein as a "circuit," module, "or" platform.

Fig. 11 is a schematic structural diagram of the device for establishing and switching the SD-WAN tunnel according to the present invention. An electronic device 600 according to this embodiment of the invention is described below with reference to fig. 11. The electronic device 600 shown in fig. 11 is only an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present invention.

As shown in fig. 11, the electronic device 600 is embodied in the form of a general purpose computing device. The components of the electronic device 600 may include, but are not limited to: at least one processing unit 610, at least one memory unit 620, a bus 630 connecting the different platform components (including the memory unit 620 and the processing unit 610), a display unit 640, and the like.

Where the memory unit stores program code that may be executed by processing unit 610 to cause processing unit 610 to perform the steps according to various exemplary embodiments of the present invention described in the method portion of establishing and switching an SD-WAN tunnel described above in this specification. For example, processing unit 610 may perform the steps as shown in fig. 1.

The storage unit 620 may include readable media in the form of volatile memory units, such as a random access memory unit (RAM) 6201 and/or a cache memory unit 6202, and may further include a read-only memory unit (ROM) 6203.

The memory unit 620 may also include a program/utility 6204 having a set (at least one) of program modules 6205, such program modules 6205 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination thereof may comprise an implementation of a network environment.

Bus 630 can be any bus representing one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

The electronic device 600 may also communicate with one or more external devices 700 (e.g., keyboard, pointing device, bluetooth device, etc.), with one or more devices that enable a user to interact with the electronic device 600, and/or with any devices (e.g., router, modem, etc.) that enable the electronic device 600 to communicate with one or more other computing devices. Such communication may occur via an input/output (I/O) interface 650. Also, the electronic device 600 may communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network such as the Internet) via the network adapter 660. The network adapter 660 may communicate with the other modules of the electronic device 600 via the bus 630. It should be appreciated that although not shown in the figures, other hardware and/or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, to name a few.

The embodiment of the invention also provides a computer-readable storage medium for storing a program, and the steps of the method for establishing and switching the SD-WAN tunnel are realized when the program is executed. In some possible embodiments, the various aspects of the invention may also be implemented in the form of a program product comprising program code means for causing a terminal device to carry out the steps according to various exemplary embodiments of the invention described in the method part of establishing and switching an SD-WAN tunnel described above in this description, when the program product is run on the terminal device.

As shown above, the system for establishing and switching an SD-WAN tunnel according to the embodiment of the present invention can alleviate a large amount of tunnel link oscillation between the main and standby access links caused by the instant exhaustion of IP network resources due to the simultaneous establishment/switching of a large number of tunnels in the SD-WAN network, thereby improving user experience.

Fig. 12 is a schematic structural diagram of a computer-readable storage medium of the present invention. Referring to fig. 8, a program product 800 for implementing the above method according to an embodiment of the present invention is described, which may employ a portable compact disc read only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited in this respect, and in this document, a readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

A computer readable storage medium may include a propagated data signal with readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A readable storage medium may be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In situations involving remote computing devices, the remote computing devices may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to external computing devices (e.g., through the internet using an internet service provider).

In summary, the invention can alleviate a large amount of tunnel link oscillation between the main and standby access links caused by instant exhaustion of IP network resources due to simultaneous establishment/switching of a large amount of tunnels in the SD-WAN network, thereby improving user experience.

The foregoing is a further detailed description of the invention in connection with specific preferred embodiments and it is not intended to limit the invention to the specific embodiments described. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. A method for establishing and switching SD-WAN tunnels is applied to an SD-WAN controller and comprises the following steps:

sending second tunnel establishment/switching application information to an underlay IP-SDN controller corresponding to a main access link, wherein the second tunnel establishment/switching application information comprises the tunnel information and an application timestamp, so that the underlay IP-SDN controller corresponding to the main access link can determine a link calculation sequence of the second tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority and sequentially select an available routing list meeting the tunnel bandwidth according to the link calculation sequence and determine available tunnels according to a plurality of pieces of tunnel establishment/switching application information received within a set time period;

sending the available routing table of the available tunnel to the client front-end device, so that the client front-end device can execute tunnel establishment/switching on the main access link according to the available routing table of the available tunnel,

wherein the first tunnel establishment/handover application information is generated based on one or more triggers of:

the client front-end device establishes a tunnel for the first time,

the main access link and the standby access link are an IP network and a mobile IP network respectively.

2. The method of claim 1, wherein before receiving the first tunnel setup/handover application information sent by the client front-end device on the active access link, the method further comprises:

storing the tunnel identifier and the tunnel priority;

3. The method of establishing and handing off an SD-WAN tunnel of claim 2, wherein the registration request message further includes a terminal serial number of the client premises equipment, and wherein prior to storing the tunnel identification and tunnel priority, further comprises:

the storing the tunnel identifier and the tunnel priority further comprises:

and storing the tunnel address information and the tunnel bandwidth.

4. The method of claim 1, wherein determining the link calculation order of the second tunnel establishment/handover application information according to the application timestamp and/or tunnel priority comprises:

determining a quasi-link calculation order of the second tunnel establishment/switching application information according to the tunnel priority from high to low;

judging whether a plurality of pieces of tunnel establishment/switching application information with the same tunnel priority exist in the quasi link calculation sequence;

5. The method of establishing and handing off an SD-WAN tunnel of claim 1, further comprising:

sending fourth tunnel establishment/switching application information to an underlay IP-SDN controller corresponding to a standby access link, wherein the fourth tunnel establishment/switching application information comprises the tunnel information and an application timestamp, so that the underlay IP-SDN controller corresponding to the standby access link can determine a link calculation order of the fourth tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority and sequentially select an available routing table meeting the tunnel bandwidth according to the link calculation order and determine available tunnels according to a plurality of pieces of tunnel establishment/switching application information received in a set time period;

6. The method of establishing and handing off an SD-WAN tunnel of claim 5, wherein the third tunnel establishment/handover application information is generated based on one or more of the following triggers:

7. An apparatus for establishing and switching SD-WAN tunnel, applied to SD-WAN controller, comprising:

a first sending module, configured to send second tunnel establishment/handover application information to an underlay IP-SDN controller corresponding to a primary access link, where the second tunnel establishment/handover application information includes the tunnel information and an application timestamp, so that the underlay IP-SDN controller corresponding to the primary access link determines, according to the application timestamp and/or a tunnel priority, a link calculation order of the second tunnel establishment/handover application information according to a plurality of pieces of tunnel establishment/handover application information received within a set time period, sequentially selects an available routing table that satisfies a tunnel bandwidth according to the link calculation order, and determines an available tunnel;

a second sending module, configured to send the available routing table of the available tunnel to the client pre-device, so that the client pre-device performs tunnel establishment/handover on the active access link according to the available routing table of the available tunnel,

the client front-end device establishes a tunnel for the first time,

8. A system for establishing and switching SD-WAN tunnels, comprising:

an SD-WAN controller configured to perform the steps of:

sending second tunnel establishment/switching application information to a first underlay IP-SDN controller corresponding to a primary access link, wherein the second tunnel establishment/switching application information comprises the tunnel information and an application timestamp, and receiving an available routing table of an available tunnel sent by the first underlay IP-SDN controller;

sending the available routing table of the available tunnel to the client front-end equipment, so that the client front-end equipment can execute tunnel establishment/switching on the main access link according to the available routing table of the available tunnel;

a first underlay IP-SDN controller configured to perform the steps of:

sequentially selecting available routing tables satisfying the tunnel bandwidth in the link calculation order, and determining available tunnels,

the client front-end device establishes a tunnel for the first time,

9. The system for establishing and handing off an SD-WAN tunnel according to claim 8,

the SD-WAN controller is further configured to perform the following steps:

sending fourth tunnel establishment/switching application information to a second underlay IP-SDN controller corresponding to a standby access link, wherein the fourth tunnel establishment/switching application information comprises the tunnel information and an application timestamp, and receiving an available routing table of an available tunnel sent by the second underlay IP-SDN controller;

sending the available routing table of the available tunnel to the client pre-equipment for the client pre-equipment to execute tunnel establishment/switching on a standby access link according to the available routing table of the available tunnel,

the system for establishing and switching the SD-WAN tunnel further comprises:

a second underlay IP-SDN controller configured to perform the steps of:

determining a link calculation order of the fourth tunnel establishment/switching application information according to the application timestamp and/or the tunnel priority according to the received multiple pieces of tunnel establishment/switching application information in a set time period;

10. The system for establishing and handing off an SD-WAN tunnel of claim 8, further comprising:

a client premises device configured to perform the steps of:

establishing/switching application information of a first tunnel sent on a main access link or establishing/switching application information of a third tunnel sent on a standby access link;

11. An apparatus for establishing and switching an SD-WAN tunnel, comprising:

a processor;

a memory having stored therein executable instructions of the processor;

wherein the processor is configured to perform the steps of the method of establishing and switching an SD-WAN tunnel of any of claims 1 to 6 via execution of the executable instructions.

12. A computer-readable storage medium storing a program, wherein the program is configured to implement the steps of the method for establishing and switching an SD-WAN tunnel according to any one of claims 1 to 6 when executed.