Communication method, communication device and communication system

Abstract

The invention provides a communication method, a communication device and a communication system. The method comprises: a first POP device of a first site in a software defined wide area network (SD-WAN) obtains topology information of the SD-WAN, and determines a first next hop of a route arriving at a second site according to the topology information of the SD-WAN. The first next hop is a third site in the SD-WAN. The method can be used in a multi-segment SD-WAN, the next hop is calculated according to the site granularity through the POP equipment of each site, the reachable route between the POP equipment is determined, the next hop of the route does not need to be arranged by a controller in a network, and the route arrangement efficiency can be improved. According to the scheme, limitation caused by controller performance can be avoided, and the method can be applied to routing arrangement of a large-scale network.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method, communication device and communication system. Background Technology

[0002] Software-defined WAN (SD-WAN), as a key practice of software-defined networking (SDN), is gradually changing the way WANs are built and managed. In current SD-WAN architectures, especially multi-segment SD-WAN architectures, the controller plays a central role. Typically, the controller orchestrates network reachability routes based on network overlay topology information, ensuring that service traffic can be transmitted efficiently and reliably within the network.

[0003] However, as networks expand, so does the complexity of the network environment. At this point, the controller's computing power can become a significant factor limiting network performance. Especially in large-scale networking scenarios, the controller needs to process massive amounts of routing information and real-time data to ensure efficient network operation. If the controller's computing power is insufficient to handle this high load, it can lead to untimely route orchestration, thereby affecting the overall network performance and stability. Summary of the Invention

[0004] This application provides a communication method, communication device, and communication system in which each station in the network determines the next-hop station for the route to the remote station, thereby solving the above-mentioned problems.

[0005] Firstly, this application provides a communication method. The method includes: a first point of presence (POP) device acquiring topology information of a Software-Defined Wide Area Network (SD-WAN). The SD-WAN topology information includes the local site identifier of each station in the SD-WAN, the adjacency relationships between stations, and address prefix information. The adjacency relationships between stations are characterized by a correspondence between the local site identifier and the remote site identifier of each station. The SD-WAN includes at least a first station, a second station, and a third station. The first POP device belongs to the first station. The address prefix information includes the local site identifier of the second station advertised by a second POP device in the second station and an Internet Protocol (IP) address. The first POP device determines the first next hop of the route to the IP address based on the SD-WAN topology information. The first next hop is the third station. The IP address may be, for example, the locator, interface address, router identifier, loopback interface address, etc., of the second POP device. The IP address may be an IPv4 address or an IPv6 address.

[0006] In the above scheme, after obtaining the site-level topology information in the SD-WAN, the first POP device can calculate the next hop of the route to any IP address at the site level. This method allows the SD-WAN to calculate the next hop to each site independently without relying on the controller for route orchestration, thereby improving routing planning efficiency, network performance, and stability. In one possible implementation, obtaining the SD-WAN topology information includes: the first POP device receiving a first packet, the first packet including node information advertised by the second POP device, the node information advertised by the second POP device including the local site identifier of the second site; the first POP device receiving a second packet, the second packet including the adjacency relationship between sites advertised by the second POP device, the adjacency relationship between sites advertised by the second POP device including the correspondence between the local site identifier and the remote site identifier of the second site; the first POP device receiving a third packet, the third packet including address prefix information advertised by the second POP device, the address prefix information advertised by the second POP device including the local site identifier of the second site and the IP address.

[0007] In the above scheme, the POP devices of each site in SD-WAN can dynamically spread their own node information, adjacency relationships between sites, and address prefix information through protocol messages.

[0008] In one possible implementation, the first, second, and third messages are Border Gateway Protocol-Link State-Shortest Path First (BGP-LS-SPF) protocol messages. Thus, each POP device can generate a BGP-LS-SPF route with the next hop at the site level. BGP-LS-SPF can also be simply referred to as BGP-SPF.

[0009] In the above scheme, the POP devices of each site in SD-WAN can spread their own node information, the adjacency relationship between sites, and the address prefix information through the BGP-LS-SPF protocol.

[0010] In one possible implementation, a first SD-WAN tunnel is established between the first site and the third site. The first SD-WAN tunnel includes multiple links, and the multiple links in the first SD-WAN tunnel form a primary backup link or a load-sharing link.

[0011] In the above scheme, setting up a primary link and a backup link ensures that data is forwarded securely. Under normal circumstances, data is forwarded to the next hop via the primary link. When the quality of the primary link deteriorates or is interrupted, data can be forwarded to the next hop via the backup link. Setting up load-sharing links, forwarding data through multiple links, can avoid the impact of excessive load on a single link on transmission performance and can also improve data forwarding efficiency.

[0012] In one possible implementation, the SD-WAN further includes a fourth site. Obtaining the SD-WAN topology information further includes: the first POP device obtaining the local site identifier and inter-site adjacency relationships of the fourth site as advertised by the fourth POP device, wherein the inter-site adjacency relationships advertised by the second POP device include the correspondence between the local site identifier and the remote site identifier of the fourth site. The method further includes: the first POP device determining a second next hop for the route to the IP address based on the SD-WAN topology information, wherein the second next hop is the fourth site.

[0013] In one possible implementation, the third station and the fourth station form a primary and backup protection on the traffic transmission path; or the third station and the fourth station form a load-sharing on the traffic transmission path.

[0014] In the above scheme, setting up primary and backup protection ensures secure data forwarding. For example, under normal circumstances, data is forwarded through the traffic transmission path between the first and third stations. When the quality degrades or is interrupted, data can be forwarded through the traffic transmission path between the first and fourth stations. Setting up load balancing, forwarding data through the traffic transmission paths between the first and third stations and between the first and fourth stations, avoids excessive load on a single traffic transmission path that could affect transmission performance and also improves data forwarding efficiency.

[0015] In one possible implementation, a first SD-WAN tunnel is established between the first site and the third site, and a second SD-WAN tunnel is established between the first site and the fourth site, wherein the first SD-WAN tunnel and the second SD-WAN tunnel form a primary and backup protection on the traffic transmission path; or the first SD-WAN tunnel and the second SD-WAN tunnel form a load sharing on the traffic transmission path.

[0016] In the above scheme, setting up primary and backup protection ensures secure data forwarding. For example, under normal circumstances, data is forwarded to the third site through the second SD-WAN tunnel. When its quality degrades or is interrupted, data can be forwarded to the fourth site through the second SD-WAN tunnel. Setting up load balancing, forwarding different data to the third and fourth sites through the first and second SD-WAN tunnels respectively, avoids excessive load on a single SD-WAN tunnel, which could affect transmission performance, and also improves data forwarding efficiency.

[0017] In one possible implementation, the first SD-WAN tunnel includes multiple links, which form a primary / backup link or a load-sharing link.

[0018] In one possible implementation, the second SD-WAN tunnel includes multiple links, which form a primary / backup link or a load-sharing link.

[0019] In the above scheme, configuring multiple links in the SD-WAN tunnel as primary and backup protection ensures secure data forwarding. For example, under normal circumstances, data is forwarded through the primary link of the first and second SD-WAN tunnels. When its quality degrades or is interrupted, data can be forwarded through the backup links of the first and second SD-WAN tunnels. By further configuring multiple links in the SD-WAN tunnel as load-sharing links, forwarding data through the links of the first and second SD-WAN tunnels, the excessive load on a single link can be avoided, thus preventing performance degradation and improving data forwarding efficiency.

[0020] In one possible implementation, the method further includes: the first POP device receiving a service flow, iterating the underlay route according to the service route, and determining at least one tunnel between the current site where the first POP device is located and the next hop, and forwarding the service flow. The next hop is the third site and / or the fourth site. The at least one tunnel includes a first tunnel between the current site and the third site, and / or a second tunnel between the current site and the fourth site.

[0021] Secondly, this application also provides a communication device. The communication device includes a transceiver module and a processing module. The transceiver module is used to perform receiving and / or sending related operations as described in the first aspect, or any possible implementation of the first aspect. The processing module is used to perform other operations besides receiving and / or sending as described in the first aspect, or any possible implementation of the first aspect. For example, the transceiver module is used to acquire topology information of a Software-Defined Wide Area Network (SD-WAN). The SD-WAN topology information includes the local site identifier of each station in the SD-WAN, the adjacency relationships between stations, and address prefix information. The adjacency relationships between stations are characterized by a correspondence between the local site identifier and the remote site identifier of each station. The SD-WAN includes at least a first station, a second station, and a third station. The first POP device belongs to the first station. The address prefix information includes the local site identifier and IP address of the second station announced by the second POP device in the second station.

[0022] Thirdly, this application also provides a communication device, including a processor and a memory. The processor is used to execute instructions stored in the memory to implement the communication method provided by the first aspect or any possible implementation of the first aspect.

[0023] It should be noted that the communication device mentioned in the second and third aspects of this application may be a network device such as a switch or router, or a component of the network device, such as a single board or line card on the network device, or a functional module on the network device, or a chip used to implement the method of this application. The embodiments of this application do not specifically limit the scope of the application.

[0024] Fourthly, this application also provides an SD-WAN communication system. The SD-WAN communication system includes multiple sites, at least one of which includes a communication device for performing the methods described in the first aspect and any one of the first aspects.

[0025] Fifthly, this application provides a computer-readable storage medium, including instructions or a computer program, which, when executed on a processor, implements the communication method provided by the first aspect above, or any possible implementation of the first aspect.

[0026] Sixthly, this application provides a computer program product, including a computer program that, when the computer program is run on a processor, implements the communication method provided by the first aspect above, or any possible implementation of the first aspect.

[0027] Any of the devices, computer storage media, or computer program products provided above are used to execute the methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects of the corresponding solutions in the corresponding methods provided above, and will not be repeated here. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of an SD-WAN structure provided in an embodiment of this application;

[0029] Figures 2a-2c This is a schematic diagram of the format of network reachability information provided in the embodiments of this application;

[0030] Figure 3 This is a flowchart of a method provided in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of routing information provided in an embodiment of this application;

[0032] Figure 5 This is a flowchart of a communication method provided in an embodiment of this application;

[0033] Figure 6 This is a flowchart of a message forwarding method provided in an embodiment of this application;

[0034] Figure 7This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0035] Figure 8 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings.

[0037] In the description of the embodiments of this application, the words "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a specific manner.

[0038] In the description of the embodiments in this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. Furthermore, unless otherwise stated, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0040] Before introducing the solution of this application, the technical terms involved in this application will be explained first.

[0041] Border Gateway Protocol - Link-State Protocol - Shortest Path First (BGP-LS-SPF): The BGP protocol uses the SPF algorithm to process and calculate link-state information. It is a path vector protocol used to exchange routing information between different autonomous systems. It is one of the core routing protocols of the Internet, responsible for managing and maintaining routing information across the Internet, ensuring that data can be correctly transmitted between different networks.

[0042] Network layer reachability information (NLRI) is a crucial piece of information contained in BGP-LS-SPF packets. Different types of NLRI can be used to carry node information for each site in SD-WAN, adjacency relationships between sites, and IP addresses. The IP addresses can include either IPv4 or IPv6 addresses.

[0043] The underlay network, also known as the foundational network, is, in a specific implementation, a network built directly on the physical layer to provide basic network interconnectivity. It consists of physical devices such as switches and routers. Underlay networks can include multiprotocol label switching-virtual private networks (MPLS-VPN), the internet, and mobile communication networks.

[0044] An overlay network, also known as a superimposed network, is a logical network layer built on top of an underlay network using virtualization technology. Overlay networks use encapsulation techniques (such as Virtual Extensible Local Area Network (VXLAN) or Network Virtualization Using Generic Routing Encapsulation (NVGRE)) to encapsulate network packets that the underlay network cannot directly process into external data packets for transmission over the underlay network.

[0045] Multi-segment SD-WAN is an important practice of software-defined networking (SDN). It's a network that forwards service flows hop-by-hop through multiple segments. For example, a segment in multi-segment SD-WAN can include a transmission path between two sites. Different segments can be interconnected based on heterogeneous networks. SD-WAN is a network architecture that abstracts network control functions from proprietary hardware and implements them in software. It allows enterprises to manage their WAN connections with lower cost, greater flexibility, and better performance. By introducing virtualization technologies and intelligent traffic management strategies, SD-WAN can optimize network resource utilization and improve data transmission efficiency and security. SD-WAN typically uses an overlay network architecture to implement its virtualization functions. SD-WAN achieves flexible configuration and dynamic adjustment of network resources by building an overlay network on top of an underlay network. In SD-WAN, the underlay network handles the actual packet forwarding and routing operations, while the overlay network provides a logical network architecture for abstracting and virtualizing network resources. Through the overlay network, SD-WAN enables communication across physical networks and provides flexible network services.

[0046] Point-of-Presence (POP) devices are key nodes in SD-WAN, allowing users to access the SD-WAN network. POP devices provide high-speed, reliable network connectivity and powerful network optimization capabilities, acting as network traffic relay stations to accelerate data transmission and optimize network traffic. POP devices can include routers or switches. Optionally, POP devices can serve as SD-WAN edges, acting as the initiation and termination point of SD-WAN tunnels, and functioning as egress CPE devices for locations such as corporate headquarters, branch offices, data centers, or cloud sites. SD-WAN tunnels between edges can be built on any wired or wireless Underlay WAN technology. Edges can be implemented in hardware or software.

[0047] A site is not only an endpoint in SD-WAN, but also the core of local network access and data transmission. A site can encompass various types. From a business perspective, data centers, infrastructure deployed by cloud service providers, corporate headquarters, and branch offices can all be considered corporate sites. Each site includes one or more Point-of-Pressure (POP) devices, etc.

[0048] In related technologies, the routing and orchestration of service flows in SD-WAN largely relies on the network controller. The controller collects topology information and service requirements between various nodes (e.g., POP devices) to orchestrate the service paths of service flows. Each service path includes the complete transmission path from the source node to the destination node. Then, the controller distributes the routing information to each node (including the source node, intermediate nodes, and destination node), and these nodes store the routing information to determine the next hop when forwarding service flows. However, the limited computing power of the controller restricts the scale of SD-WAN deployments. Moreover, when the topology of the overlay network changes, the controller needs to re-orchestrate routes; if the response to network topology changes is slow, it will affect network reliability.

[0049] Furthermore, in some possible implementations, devices in a site advertise SD-WAN topology information at the granularity of adjacent links. When calculating routes, the routes iterate to specific physical links. When a new tenant or service is added to the site, the route needs to be recalculated based on the specific link accessed by the tenant, which is complex to configure and has low service activation efficiency.

[0050] To address the aforementioned issues, the communication method provided in this application uses a site-level approach, with the POP device determining the next hop of the route. When adding new tenants or services, the POP device requires no configuration changes when connecting to the backbone network, resulting in efficient service activation. The method provided in this application eliminates the need for a controller to orchestrate the next hop of the route, thus improving routing orchestration efficiency. This solution also avoids the limitations imposed by controllers and can be applied to routing orchestration in larger-scale networks.

[0051] Figure 1 This is a schematic diagram of a multi-segment SD-WAN structure provided in an embodiment of this application.

[0052] like Figure 1 As shown, this multi-segment SD-WAN can include multiple sites and multiple networks, with each site connected to one or more networks. The multiple sites may include, but are not limited to, […]. Figure 1 Sites 1 to 4 shown (hereinafter referred to as site1-site4), and multiple networks including but not limited to Figure 1 Networks 1 through 4 are shown. (For example...) Figure 1 As shown, site1 communicates with site3 through network 1 and network 2, site3 communicates with site2 through network 3 and network 4, site1 also communicates with site4 through network 1 and network 2, and site4 communicates with site2 through network 3 and network 4.

[0053] These networks can include, but are not limited to, the MPLS-VPN, the internet, or mobile communication networks mentioned above. It is understood that... Figure 1 The network architecture diagram shown is merely an example; in actual network deployments applicable to this application, Figure 1 The multiple networks shown can include two or more networks. Site 1 and Site 2 can be connected via, for example... Figure 1 The network can communicate with multiple networks, or it can communicate through one or more stations. This application does not limit the specific application scenario. For example, in Figure 1 In the network shown, station 1 communicates with station 2 through station 3. In actual network configuration, station 1 and station 2 may pass through multiple stations, and this application does not impose specific restrictions on this.

[0054] exist Figure 1 In the SD-WAN shown, stations connected to the same network can communicate via SD-WAN tunnels, or via other types of tunnels (such as Virtual Extended Local Area Network (VXLAN) tunnels). The following description uses an SD-WAN tunnel as an example to illustrate the method described in this application. Figure 1 As shown, SD-WAN tunnel 1 is established between site1 and site3, SD-WAN tunnel 3 is established between site1 and site4, SD-WAN tunnel 2 is established between site2 and site3, and SD-WAN tunnel 4 is established between site2 and site4.

[0055] An SD-WAN tunnel established between two sites can include one or more connections. Each site can include one or more POP devices. The POP devices at the two sites can communicate through these one or more connections. Figure 1 As shown, SD-WAN tunnel 1 between site1 and site3 includes Figure 1 Links 11 and 12 are shown, and these two links pass through network 1 and network 2 respectively. POP devices in site 1 and site 3 can communicate via links 11 and 12. Similarly, POP devices in site 1 and site 4 can communicate via links 31 and 32 of tunnel 3, POP devices in site 4 and site 2 can communicate via links 41 and 42 of tunnel 4, and POP devices in site 3 and site 2 can communicate via links 21 and 22 of tunnel 2.

[0056] exist Figure 1The SD-WAN shown may also include a route reflector (RR). Figure 1 (Not shown), each site establishes a BGP neighbor relationship with the route reflector (RR). Thus, each site's POP device advertises SD-WAN topology information to other sites via the RR. In one specific implementation, each site establishes a BGP-LS-SPF neighbor relationship with the RR and advertises SD-WAN topology information via BGP-LS-SPF messages. In one specific implementation, the format of the BGP-LS-SPF message can refer to RFC 9552 published by the Internet Engineering Task Force (IETF). This application expands upon this by extending the information carried in the relevant fields. In this application, the local site identity (site ID) of the POP device can be carried through the Node NLRI; the adjacency relationship between sites can be carried through the Link NLRI, which is characterized by the correspondence between the site's local site identity and the remote site identity; and the address prefix information can be carried through the IP prefix NLRI, which includes the local site identity and IP address of the POP device. Compared to RFC9552, the node descriptor no longer carries the node's IP address, but instead carries the site identifier to which the node belongs. Accordingly, RFC9552, which describes adjacency based on node IP address pairs, has been extended to describe adjacency based on the site identifiers of each site. This makes it easier for each POP device to obtain SD-WAN topology information at the site level and to calculate the next hop of the route at the site level.

[0057] The following is combined with Figures 2a-2c Examples of the formats of Node NLRI, Link NLRI, and IP prefix NLRI used for announcing SD-WAN topology information provided in this application are given.

[0058] like Figure 2a As shown, Node NLRI includes a protocol identity (protocol-ID) field, an identifier field, and local node descriptors fields. The local node descriptors field carries the local site identifier.

[0059] like Figure 2bAs shown, Link NLRI includes a protocol identifier field, an identifier field, a local node descriptor field, and remote node descriptors fields. Optionally, Link NLRI may also include link descriptors fields. The local node descriptor field carries the identifier of the local site to which the node belongs, the remote node descriptor field carries the identifier of the adjacent remote site, and the link descriptors field carries the site's connection information. The site's connection information may include one or more of the following: the identifier of the tunnel between sites, the tunnel's metric, the identifier of the links contained in the tunnel, and the metrics of the links contained in the tunnel. The metrics may include, but are not limited to, one or more of the following parameters: cost, latency, throughput, and error rate.

[0060] like Figure 2c As shown, the IP prefix NLRI includes a protocol identifier field, an identifier field, a local node descriptor field, and a prefix descriptor field. The prefix descriptor field carries the IP address.

[0061] It should be noted that, Figures 2a-2c The bytes included in the fields shown are merely illustrative. Those skilled in the art will understand that this application does not impose specific limitations on the number of bytes in each field of the Node NLRI, Link NLRI, and IP prefix NLRI described above, and the fields used to carry SD-WAN topology information at the site level in the above examples may also use other names; this application does not impose specific limitations. In other words, the names of the above fields should not constitute a limitation on this application.

[0062] The following is combined with Figure 3 This application introduces a communication method 300, which can be used for... Figure 1 In the network architecture shown, by Figure 1 This can be performed on any POP device in any of the sites shown, such as POP device 11 and POP device 12 in site1. The following description uses POP device 11 as an example to illustrate method 300.

[0063] like Figure 3 As shown, the method 300 may include S301 and S302.

[0064] S301, POP device 11 obtains SD-WAN topology information.

[0065] In this embodiment, the SD-WAN topology information may include the adjacency topology information of site1 and other sites. Each site in the SD-WAN can advertise its own adjacency topology information to other sites. In this application, the adjacency topology information of each site includes, but is not limited to, the local site identifier of each site, the adjacency relationship between the local site and the remote site, and address prefix information.

[0066] Taking site1 as an example, POP device 11 advertises the adjacency topology information of site1 to POP devices of other sites through the route reflector RR. POP11 receives the site adjacency topology information advertised by POP devices of other sites through RR.

[0067] For example, POP device 11 sends the adjacency topology information of site1 to RR via BGP-LS-SPF messages. BGP-LS-SPF is a widely used protocol in the industry for topology calculation and has good device compatibility. (See attached...) Figure 1In the scenario shown, the local node descriptor in the Node NLRI advertised by POP device 11 carries the site ID of site1, the local node descriptor in the Link NLRI carries the site ID of site1, the remote node descriptor carries the site ID of site3 or site4, and the IP prefix NLRI carries the corresponding IP address 1 and the site ID of site1. POP device 11 receives the adjacency topology information of its respective sites advertised by POP devices 21, 31, and 41. Specifically, the local node descriptor in the Node NLRI advertised by POP device 21 carries the site ID of site2, the local node descriptor in the Link NLRI carries the site ID of site2, the remote node descriptor carries the site ID of site3 or site4, and the IP prefix NLRI carries the corresponding IP address 2 and the site ID of site2. The local node descriptor in the Node NLRI advertised by POP device 31 carries the site ID of site3, the local node descriptor in the Link NLRI carries the site ID of site3, the remote node descriptor carries the site ID of site1 or site2, and the IP prefix NLRI carries the corresponding IP address 3 and the site ID of site3. Similarly, the local node descriptor in the Node NLRI advertised by POP device 41 carries the site ID of site4, the local node descriptor in the Link NLRI carries the site ID of site4, the remote node descriptor carries the site ID of site1 or site2, and the IP prefix NLRI carries the corresponding IP address 4 and the site ID of site4. After receiving the adjacency topology information corresponding to each site, POP11 learns that site2 is adjacent to either site3 or site4, while site4 is adjacent to both site1 and site2, and site3 is adjacent to both site1 and site2. Each POP device in the network, based on the same mechanism, can obtain the adjacency topology information of its own site and that of each other's sites, thereby obtaining the SD-WAN topology information. For details on how BGP-LS-SPF messages carry site link topology information, please refer to [link / reference]. Figures 2a-2c The corresponding textual explanations will not be repeated here.

[0068] Alternatively, each site may also advertise its adjacency topology information based on the internal gateway protocol (IGP) or other BGP address family protocols, which will not be elaborated here.

[0069] Other sites in this SD-WAN advertise their respective site's adjacency topology information to the route reflector (RR) in a similar manner to site1. The specific implementation is described in the above text and will not be repeated here.

[0070] Optionally, BGP neighbors, such as BGP-LS-SPF neighbors, can be established directly between sites. In this way, a site can directly announce its adjacency topology information to other sites.

[0071] S302, POP device 11 determines the next hop of the route from site1 to a certain IP address (to distinguish it from traditional service routes, the route will be referred to as the underlay route in the following text) based on the SD-WAN topology information.

[0072] POP device 11 can determine the next hop of the underlay route from POP device 11 to other POP devices using the Shortest Path First (SPF) algorithm based on the SD-WAN topology information. For example, for IP address 2 advertised by POP device 21 in site 2, POP device 11 calculates and saves the underlay route to IP address 2 based on the obtained SD-WAN topology information. The next hop of the underlay route is represented by the site ID. Figure 1 In the scenario shown, POP device 11 determines the next hop of the underlay route to IP address 2 published by POP device 21 based on the adjacency topology information published by each POP device. Optionally, since POP device 11 can reach site 2 through either site 3 or site 4, POP device 11 determines site 3 or site 4 as the next hop of the underlay route according to the routing principle. Optionally, POP device 11 can designate site 3 and site 4 as the primary next hop and backup next hop, respectively. When the path from the current site to the primary next hop site is unreachable, traffic can be switched to the backup next hop site to ensure service continuity. Optionally, POP device 11 can designate site 3 and site 4 as the next hop to IP address 2 to achieve load balancing of service flows. Optionally, the underlay routing information stored by the POP device includes not only the destination address and next hop, but also tunnel identifiers between the current site (e.g., site 1) and the next hop (e.g., site 3 or site 4). Figure 4 An example of possible underlay routing information is given. Each underlay routing entry includes, but is not limited to, the destination address, the next hop, and the tunnel ID for reaching that next hop.

[0073] Optionally, the SD-WAN tunnel 1 between site1 and site3 includes link 11 and link 12. POP device 11 can use link 11 as the primary link and link 12 as the backup link. Correspondingly, POP device 11 can also record the identifiers of the primary and backup links in the corresponding underlay routing information. POP device 11 can determine the primary and backup links based on link metrics. Multiple links forming primary and backup links can improve the reliability of service forwarding. Site1 sends service flows to the next-hop site through the primary link. When the quality of the primary link degrades or is interrupted, site1 can send service flows to the next-hop site through the backup link. Optionally, if all links included in the tunnel between sites are interrupted, the site can republish the adjacency topology information to re-determine the next hop of the underlay route.

[0074] Optionally, POP device 11 can also load-share links 11 and 12 of tunnel 1, that is, load-share the service flow through links 11 and 12. Optionally, in response to POP device 11 reaching site 2 through multiple sites (e.g., site 3 and site 4), POP device 11 can form primary / backup protection or load sharing among the multiple sites. In this case, POP device 11 can form primary / backup protection or load sharing for the tunnel between site 1 and multiple sites. The process of transmitting service flow through primary / backup protection and load sharing will be discussed later in conjunction with... Figure 6 We will introduce it here, but will not go into too much detail.

[0075] In method 300 described above, each site's POP device obtains SD-WAN topology information based on the adjacency topology information announced by each POP device at the site-by-site granularity. This allows for the planning of the next hop to the remote site at the site-by-site granularity, effectively addressing the limitation on the network scale of multi-segment SD-WAN caused by the controller's computing power. When applied to multi-segment SD-WAN, method 300 enables newly added sites to network more efficiently, thereby improving network efficiency. Furthermore, this solution eliminates the need for controller routing orchestration, allowing for faster response to topology changes and enhancing network reliability. Moreover, when a site adds a tenant or service, the POP device's connection to the backbone network requires no configuration changes, resulting in efficient service activation.

[0076] Figure 5 This is a flowchart of a communication method 500 provided in an embodiment of this application. Method 500 can specifically be used to implement method 300. Method 500 can be applied to a POP device in any site within an SD-WAN. Method 500 can be used for... Figure 1The network scenario shown can be implemented in method 300. For example, the first station in method 500 may include... Figure 1 For any of the sites shown (e.g., site 1), the second site in method 500 could be, for example, a... Figure 1 The third site in method 500, as shown in site 2, could be, for example, site 2. Figure 1 One of the sites shown in site 3 or site 4, the fourth site in method 500 could be, for example, a site that is either a site 3 or a site 4. Figure 1 Another site in site 3 or site 4 shown. The first POP device can be any POP device in any site (e.g., Figure 1 The POP device 11 or POP device 12 shown can be any POP device in any site (e.g., Figure 1 The third POP device (POP device 21 or POP device 22 shown) can be any POP device in the third site (e.g., POP device 21 or POP device 22 shown). Figure 1 POP device 41, POP device 42, POP device 31 or POP device 32 shown. Figure 1 The network scenario shown is only a specific application example of Method 500 and should not be construed as a limitation of Method 500.

[0077] like Figure 5 As shown, the method 500 may include the following steps S501 and S502. The following examples illustrate this. Figure 1 Taking site1 in the SD-WAN example, for example, Figure 5 The steps are described below.

[0078] S501, the first POP device acquires the topology information of the Software-Defined Wide Area Network (SD-WAN). The SD-WAN topology information includes the local site identifier of each station in the SD-WAN, the adjacency relationships between stations, and address prefix information. The adjacency relationships between stations are represented by the correspondence between the local site identifier and the remote site identifier of each station. The SD-WAN includes at least a first station, a second station, and a third station. The first POP device belongs to the first station. The address prefix information includes the local site identifier and IP address of the second station advertised by the second POP device in the second station. The IP address can be, for example, the locator, interface address, router identifier, loopback interface address, etc. of the second POP device. This IP address can be an IPv4 address or an IPv6 address.

[0079] S502, the first POP device determines the first next hop of the route (underlay route) to the IP address based on the SD-WAN topology information. The first next hop is the third site. Optionally, the first POP device obtaining the SD-WAN topology information may include the following steps.

[0080] The first POP device receives a first message, which includes node information announced by the second POP device. The node information announced by the second POP device includes the local site identifier of the second site.

[0081] The first POP device receives a second message, which includes the adjacency relationships between stations announced by the second POP device. These adjacency relationships include the correspondence between the local station identifier and the remote station identifier of the second station. For example, when the second station is adjacent to the third station, the second POP device announces its own station identifier as the identifier of the second station and the remote station identifier as the station identifier of the third station, thereby announcing the adjacency relationship between the second and third stations to other POP devices. Similarly, when the second station is also adjacent to a fourth station, the second POP device announces the adjacency relationship between the second and fourth stations to other POP devices using the same mechanism. In this case, the local station identifier is the identifier of the second station, and the remote station identifier is the station identifier of the fourth station. That is, each POP device in the network (including the second POP device) announces the adjacency relationship between its own station and each adjacent remote station to other POP devices in the network.

[0082] The first POP device receives a third message, which includes address prefix information advertised by the second POP device. The address prefix information advertised by the second POP device includes the local site identifier and IP address of the second site.

[0083] Optionally, the first, second, and third messages are Border Gateway Protocol-Link State Protocol-Shortest Path First (BGP-LS-SPF) messages. The underlay route is a BGP-LS-SPF route.

[0084] Optionally, a first SD-WAN tunnel is established between the first site and the third site. The first SD-WAN tunnel includes multiple links, and the multiple links within the first SD-WAN tunnel form a primary backup link or a load-sharing link.

[0085] Optionally, SD-WAN also includes a fourth site. Obtaining the topology information of SD-WAN may further include: the first POP device obtaining the local site identifier of the fourth site and the adjacency relationship between the sites announced by the fourth POP device in the fourth site; and the adjacency relationship between the sites announced by the second POP device including the correspondence between the local site identifier and the remote site identifier of the fourth site.

[0086] Optionally, method 500 may further include: the first POP device determining a second next hop for the route to the IP address based on the SD-WAN topology information, wherein the second next hop is a fourth site.

[0087] Optionally, the third and fourth sites form a primary and backup protection mechanism on the traffic transmission path, or the third and fourth sites form a load-sharing mechanism on the traffic transmission path.

[0088] Optionally, a first SD-WAN tunnel is established between the first site and the third site, and a second SD-WAN tunnel is established between the first site and the fourth site, wherein the first SD-WAN tunnel and the second SD-WAN tunnel form a primary and backup protection on the traffic transmission path; or, the first SD-WAN tunnel and the second SD-WAN tunnel form a load sharing on the traffic transmission path.

[0089] Optionally, the first SD-WAN tunnel includes multiple links, and the multiple links in the first SD-WAN tunnel form a primary backup link or a load-sharing link; the second SD-WAN tunnel includes multiple links, and the multiple links in the second SD-WAN tunnel form a primary backup link or a load-sharing link.

[0090] Optionally, method 500 further includes: the first POP device receiving a service flow, iterating the underlay route according to the service route, and determining at least one tunnel between the current site where the first POP device is located and the next hop, and forwarding the service flow. The next hop is the third site and / or the fourth site. The at least one tunnel includes a first SD-WAN tunnel between the current site and the third site, and / or a second SD-WAN tunnel between the current site and the fourth site.

[0091] The specific implementation of each step of the above method 500 is similar to that of method 300. Please refer to the relevant description of method 300 above, which will not be repeated here.

[0092] Figure 6 This application provides a flowchart of a packet forwarding method 600. This method 600 can be applied to a first site in an SD-WAN. The SD-WAN may include... Figure 1 The SD-WAN shown here, the first site may include SD-WAN Figure 1 Any of the sites shown (e.g., site1).

[0093] like Figure 6 As shown, the method 600 may include the following steps S601 to S603.

[0094] S601, the first POP device in a Software-Defined Wide Area Network (SD-WAN) receives service flows. The SD-WAN includes at least a first site, a second site, a third site, and a fourth site, and the first POP device belongs to the first site.

[0095] The first POP device can be, for example, a Figure 1 POP device 11 in site1 shown

[0096] S602, the first POP device looks up the service route (e.g., VPN route), iterates the underlay route based on the service route, and determines how to forward the service flow through the tunnel between the first site and the next-hop site. The next-hop site is either the third site or the fourth site.

[0097] S603, the first POP device forwards the service flow to the third and / or fourth site.

[0098] When there is only one next hop, the first POP device can forward service flows through the tunnel between the first site and that next hop. For example, when the next hop is site3, POP device 11 can forward service flows through the tunnel between site1 and site3. Similarly, when the next hop is site4, POP device 11 can forward service flows through the tunnel between site1 and site4.

[0099] Optionally, if the tunnel between site1 and the next hop site includes multiple links, the first POP device can form a primary / backup protection or load sharing among the multiple links.

[0100] When multiple links form a primary and backup protection mechanism, the POP device 11 can forward the service flow through the primary link. If the primary link fails or its performance degrades, the POP device can forward the service flow through the backup link. The POP device 11 can determine the primary and backup links based on the metrics of multiple links; the specific determination process is not limited in this embodiment.

[0101] With load sharing across multiple links, POP device 11 can forward the service flow through multiple links. That is, each link sends a portion of the traffic in the service flow. Load sharing across multiple links avoids the impact of a single link's high load on the service flow's transmission efficiency. In other words, load sharing across multiple links improves the transmission efficiency of the service flow.

[0102] When there are multiple next hops, the first POP device can form a primary / backup protection or load balancing mechanism between the first site and multiple next hops. The following example illustrates this with next hops including site3 and site4.

[0103] In the case of multiple tunnels forming a primary and backup protection mechanism, the tunnel between site1 and site3 can serve as the primary tunnel, and the tunnel between site1 and site4 can serve as the backup tunnel. POP device 11 can forward the service flow through the primary tunnel. If the primary tunnel fails or its performance degrades, POP device 11 can forward the service flow through the backup tunnel. Optionally, POP device 11 can determine the primary and backup links based on the metric values ​​of the tunnel between site1 and site3, and the tunnel between site1 and site4. The specific determination process is not specifically limited in this embodiment.

[0104] With load sharing across multiple tunnels, POP device 11 can forward the service flow through the tunnel between site1 and site3, and the tunnel between site1 and site4. That is, the tunnel between site1 and site3, and the tunnel between site1 and site4, each send a portion of the traffic in the service flow. Load sharing across multiple tunnels avoids high load on a single tunnel, which could affect transmission efficiency. In other words, load sharing across multiple tunnels improves traffic transmission efficiency. Optionally, when POP device 11 sends a portion of the service flow through the tunnel between site1 and site3, the multiple links included in the tunnel between site1 and site3 can further form primary / backup protection or load sharing. For details, please refer to the above description of primary / backup protection and load sharing across multiple links; it will not be repeated here.

[0105] When there are multiple next hops, the first POP device can form a primary / backup protection or load balancing system for multiple sites. The following example illustrates this with next hops including site3 and site4.

[0106] In a scenario where multiple sites form a primary and backup protection network, POP device 11 can designate site3 as the primary site and site4 as the backup site. POP device 11 can forward the service flow through the tunnel between site1 and the primary site. If the tunnel between site1 and the primary site fails or its performance degrades, POP device 11 can forward the service flow through the tunnel between site1 and the backup site. Optionally, POP device 11 can determine the primary and backup sites based on the metric values ​​of the tunnel between site1 and site3, and the tunnel between site1 and site4. The specific determination process is not limited in this embodiment.

[0107] When load sharing is achieved across multiple sites, the POP device 11 can forward the service flow through the tunnels between site1 and site3, and between site1 and site4. That is, the tunnels between site1 and site3, and between site1 and site4, each send a portion of the traffic in the service flow. Load sharing across multiple sites avoids high load on a single site from affecting transmission efficiency. In other words, load sharing across multiple sites improves traffic transmission efficiency. Optionally, when the POP device 11 sends a portion of the service flow through the tunnel between site1 and site3, the multiple links included in the tunnel between site1 and site3 can further form primary / backup protection or load sharing. For details, please refer to the above description of primary / backup protection and load sharing for multiple links; it will not be repeated here.

[0108] Figure 7 This is a schematic diagram of the structure of a communication device 700 provided in an embodiment of this application. The communication device 700 can be used to implement some or all of the operations in the methods 300, 500 or 600 described above.

[0109] The communication device 700 can be used Figure 1 In the network scenario shown, implement Figure 1 Some or all of the operations performed by any POP device at any of the shown sites. For example... Figure 7 As shown, the communication device 700 includes a transceiver module 701 and a processing module 702. The transceiver module 701 performs operations related to receiving and / or sending in the methods described above, while the processing module 702 performs other operations besides receiving and / or sending in the methods described above.

[0110] For example, when the communication device 700 executes method 500, the transceiver module 701 is used to obtain the topology information of the SD-WAN. Specifically, the communication device 700 obtains the adjacency topology information advertised by other POP devices through the transceiver module 701, thereby obtaining the topology information of the SD-WAN. The processing module 702 is used to determine the first next hop of the route (underlay route) to the IP address based on the topology information of the SD-WAN, where the first next hop is the third site.

[0111] In one possible implementation, the transceiver module 701 is specifically configured to receive a first message, the first message including node information advertised by the second POP device, the node information advertised by the second POP device including the local site identifier of the second site. The transceiver module 701 is further configured to receive a second message, the second message including the adjacency relationship between sites advertised by the second POP device, the adjacency relationship between sites advertised by the second POP device including the correspondence between the local site identifier and the remote site identifier of the second site. The transceiver module 701 is further configured to receive a third message, the third message including address prefix information advertised by the second POP device, the address prefix information advertised by the second POP device including the local site identifier of the second site and the IP address.

[0112] In one possible implementation, the first message, the second message, and the third message are Border Gateway Protocol-Link State Protocol-Shortest Path First (BGP-LS-SPF) messages.

[0113] In one possible implementation, a first SD-WAN tunnel is established between the first site and the third site. The first SD-WAN tunnel includes multiple links, and the multiple links in the first SD-WAN tunnel form a primary backup link or a load-sharing link.

[0114] In one possible implementation, the SD-WAN further includes a fourth site. The transceiver module 701 is further configured to obtain the local site identifier of the fourth site and the adjacency relationships between sites advertised by the fourth POP device in the fourth site, wherein the adjacency relationships between sites advertised by the second POP device include the correspondence between the local site identifier and the remote site identifier of the fourth site. The processing module 702 is further configured to determine the second next hop of the route (underlay route) to the second site based on the SD-WAN topology information, wherein the second next hop is the fourth site.

[0115] In one possible implementation, the third station and the fourth station form a primary and backup protection on the traffic transmission path; or the third station and the fourth station form a load-sharing on the traffic transmission path.

[0116] In one possible implementation, a first SD-WAN tunnel is established between the first site and the third site, and a second SD-WAN tunnel is established between the first site and the fourth site, wherein the first SD-WAN tunnel and the second SD-WAN tunnel form a primary and backup protection on the traffic transmission path; or the first SD-WAN tunnel and the second SD-WAN tunnel form a load sharing on the traffic transmission path.

[0117] In one possible implementation, the first SD-WAN tunnel includes multiple links, which form a primary / backup link or a load-sharing link; the second SD-WAN tunnel includes multiple links, which form a primary / backup link or a load-sharing link.

[0118] It should be noted that, Figure 7 The communication device 700 shown here, when executing the communication methods described above, is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the communication device 700 provided in the above embodiments belongs to the same concept as the communication method embodiments shown in methods 300, 500 and 600. For details of its specific implementation process, please refer to the method embodiments shown in methods 300, 500 and 600, which will not be repeated here.

[0119] Figure 8 This is a schematic diagram of the hardware structure of a communication device 800 provided in an embodiment of this application. The communication device 800 can be used to implement some or all of the operations in the methods 300, 500, or 600 described above. The communication device 800 can be used for... Figure 1 In the network scenario shown, implement Figure 1 Some or all of the operations performed by any POP device at any of the sites shown.

[0120] like Figure 8 As shown, the communication device 800 may include a processor 810, a memory 820 coupled to the processor 810, and a transceiver 830. The transceiver 830 may be, for example, a communication interface or an optical module.

[0121] Processor 810 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. Processor 810 may also be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination of an ASIC and a PLD. The aforementioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. Processor 810 may refer to a single processor or may include multiple processors.

[0122] The memory 820 may include volatile memory, such as random-access memory (RAM); it may also include non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); or it may include a combination of the above types of memory. The memory 820 may refer to a single memory or may include multiple memories. In one embodiment, the memory 820 stores computer-readable instructions, which include multiple software modules, such as a transceiver module 821 and a processing module 822. After executing each software module, the processor 810 can perform corresponding operations according to the instructions of each software module. In this embodiment, the operation performed by a software module actually refers to the operation performed by the processor 810 according to the instructions of the software module.

[0123] In one example, communication device 800 corresponds to the first POP device in method 500. Transceiver 830 is used to perform the transmit / receive operations performed by the first POP device. Processor 810 is used to perform operations other than transmit / receive operations performed by the first POP device. For example, transceiver 830 is used to obtain SD-WAN topology information, which includes the local site identifier of each site in the SD-WAN, the adjacency relationships between sites, and address prefix information. The adjacency relationships between sites are characterized by the correspondence between the local site identifier and the remote site identifier of each site. The address prefix information includes the local site identifier and IP address of the second site advertised by the second POP device in the second site. Processor 810 is used to determine the first next hop of the route (underlay route) to the IP address based on the SD-WAN topology information, where the first next hop is the third site.

[0124] This application also provides a communication system. This communication system may include, for example, […]. Figure 1 The SD-WAN shown, or the sites within that SD-WAN. This communication system may include... Figure 7 and / or Figure 8 The communication device shown. The communication device included in this communication system can be used to perform the methods 300, 500 and / or 600 described above.

[0125] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0126] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. It should be understood that in the embodiments of this application, the order of the process numbers does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0127] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A communication method characterized by comprising: The method comprises: A first point of presence (POP) device acquires topology information of a software-defined wide area network (SD-WAN), wherein the topology information of the SD-WAN comprises local site identifiers of each site in the SD-WAN, adjacency relationships between sites, and address prefix information, the adjacency relationships between sites are represented by a corresponding relationship between local site identifiers and remote site identifiers of each site, the SD-WAN comprises at least a first site, a second site, and a third site, the first POP device belongs to the first site, and the address prefix information comprises a local site identifier of the second site and an IP address of a second POP device in the second site, which are announced by the second POP device. The first POP device determines a first next hop of a route to the IP address according to the topology information of the SD-WAN, and the first next hop is the third site.

2. The method of claim 1, wherein, Acquiring the topology information of the SD-WAN comprises: The first POP device receives a first packet, and the first packet comprises node information announced by the second POP device, wherein the node information announced by the second POP device comprises the local site identifier of the second site. The first POP device receives a second packet, and the second packet comprises adjacency relationships between sites announced by the second POP device, wherein the adjacency relationships between sites announced by the second POP device comprise a corresponding relationship between the local site identifier of the second site and a remote site identifier. The first POP device receives a third packet, and the third packet comprises address prefix information announced by the second POP device, wherein the address prefix information announced by the second POP device comprises the local site identifier of the second site and the IP address of the second POP device.

3. The method of claim 2, wherein, The first packet, the second packet, and the third packet are border gateway protocol-link state protocol-shortest path first (BGP-LS-SPF) packets.

4. The method according to any one of claims 1 to 3, characterized in that, The route is a BGP-LS-SPF route.

5. The method according to any one of claims 1 to 4, characterized in that, A first SD-WAN tunnel is established between the first site and the third site, and the first SD-WAN tunnel comprises a plurality of links, and the plurality of links in the first SD-WAN tunnel form primary and backup links or load sharing links.

6. The method according to any one of claims 1 to 5, characterized in that, The SD-WAN further comprises a fourth site, and acquiring the topology information of the SD-WAN further comprises: The first POP device acquires a local site identifier of the fourth site and adjacency relationships between sites announced by a fourth POP device in the fourth site, wherein the adjacency relationships between sites announced by the second POP device comprise a corresponding relationship between the local site identifier of the fourth site and a remote site identifier. The method further comprises: The first POP device determines a second next hop of a route to the IP address according to the topology information of the SD-WAN, and the second next hop is the fourth site.

7. The method of claim 6, wherein: The third site and the fourth site form primary and backup protection on a traffic transmission path; or The third site and the fourth site form primary and backup protection on a traffic transmission path; or The third site and the fourth site form load sharing on a traffic transmission path.

8. The method of claim 6, wherein, A first SD-WAN tunnel is established between the first site and the third site, and a second SD-WAN tunnel is established between the first site and the fourth site, wherein, The first SD-WAN tunnel and the second SD-WAN tunnel form active-standby protection on a traffic transmission path; or The first SD-WAN tunnel and the second SD-WAN tunnel form load sharing on a traffic transmission path.

9. The method of claim 8, wherein, The first SD-WAN tunnel includes a plurality of links, and the plurality of links in the first SD-WAN tunnel form active-standby links or load sharing links; the second SD-WAN tunnel includes a plurality of links, and the plurality of links in the second SD-WAN tunnel form active-standby links or load sharing links.

10. A communications device, characterized by The communication device comprises: a transceiver module and a processing module; The transceiver module is configured to perform the receiving and / or transmitting operations of any one of claims 1-9 performed by the first POP device; The processing module is configured to perform operations other than the receiving and / or transmitting operations of any one of claims 1-9 performed by the first POP device.

11. A communications device, characterized by The communication device comprises a processor and a memory, wherein the processor is configured to execute instructions stored in the memory to enable the communication device to implement the method of any one of claims 1-9.

12. A communication system, characterized by The communication system comprises the communication device of claim 10 or claim 11.

13. A computer-readable storage medium, characterized in that, The computer program product comprises instructions which, when executed on a computer, cause the computer to implement the method of any one of claims 1-9.

14. A computer program product, characterised in that, The computer program product comprises instructions which, when executed on a computer, cause the computer to implement the method of any one of claims 1-9.

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