Cloud private line communication method, access switch and gateway device

Abstract

The invention discloses a cloud private line communication method, an access switch and gateway equipment, which are applied to scenes of bidirectional forwarding detection, cloud communication and the like of a cloud private line. The method comprises the following steps: an access switch receives BFD message information, wherein the BFD message information comes from a user edge router; sending the BFD message information to a first gateway device and a second gateway device, so as to establish two BFD sessions with the first gateway device and the second gateway device at the cloud private line gateway side through a user edge router, and provide a dual BFD session mechanism; when first closed state message information generated based on the dual BFD session is not received, determining that at least one cloud private line link in the first cloud private line link and the second cloud private line link is in normal communication; and instructing the user edge router to perform communication between the user edge router and the cloud private line gateway through at least one cloud private line link with normal communication, and maintaining the first BFD session and the second BFD session to ensure the stability of cloud private line communication.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to a cloud private line communication method, access switch and gateway device. Background Technology

[0002] Current cloud private line systems generally determine the connection status between user equipment and cloud private line gateway equipment based on Bidirectional Forwarding Detection (BFD) sessions. However, when the cloud private line gateway equipment needs to be switched over due to failure, BFD detection may fail, resulting in unstable cloud private line communication. Summary of the Invention

[0003] This application provides a cloud private line communication method, access switch, and gateway device. By establishing two BFD sessions simultaneously with the first and second gateway devices on the cloud private line gateway side through the user edge router, a dual BFD session mechanism is provided to reduce the probability of overall BFD session jitter caused by single path jitter, thus ensuring the stability of cloud private line communication.

[0004] On one hand, this application provides a cloud private line communication method applicable to a cloud private line communication system. The cloud private line communication system includes a user edge router, an access switch, and a cloud private line gateway. A first gateway device and a second gateway device are configured on the cloud private line gateway. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The method includes:

[0005] The access switch receives bidirectional forwarding detection (BFD) packets, wherein the BFD packets originate from the user edge router.

[0006] The access switch sends the BFD message information to the first gateway device and the second gateway device, so that the first gateway device establishes a first BFD session with the state information configured as execution between the user edge router and the first gateway device based on the BFD message information, and so that the second gateway device establishes a second BFD session with the state information configured as execution between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session;

[0007] When the access switch does not receive the first shutdown status message information fed back by the first gateway device, it determines that at least one of the first cloud private line link and the second cloud private line link is communicating normally. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first shutdown status message information is generated when it is determined that the status information of the first BFD session switches from the execution state to the shutdown state, and the status information of the second BFD session switches from the execution state to the shutdown state.

[0008] The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and to maintain the first BFD session and the second BFD session.

[0009] On the other hand, this application provides a cloud private line communication method applicable to a cloud private line communication system. The cloud private line communication system includes a user edge router, an access switch, a cloud private line gateway, and a database. The cloud private line gateway is configured with a first gateway device and a second gateway device. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The database is connected to the first gateway device and the second gateway device respectively. The method includes:

[0010] The first gateway device receives bidirectional forwarding detection (BFD) message information sent through the access switch, wherein the BFD message information originates from the user edge router;

[0011] The first gateway device establishes a first BFD session with the state information configured as execution state between the user edge router and the first gateway device based on the BFD message information;

[0012] The first gateway device sends the negotiated BFD parameter information from the first BFD session to the database, so that the second gateway device establishes a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information sent by the access switch and the negotiated BFD parameter information from the first BFD session obtained from the database.

[0013] When the first gateway device does not obtain the first closed state message information, it is determined that at least one of the first cloud private line link and the second cloud private line link is communicating normally. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state.

[0014] The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and to maintain the first BFD session and the second BFD session.

[0015] On the other hand, this application provides an access switch applicable to an access switch in a cloud private line communication system. The cloud private line communication system includes a user edge router, the access switch, and a cloud private line gateway. The cloud private line gateway is configured with a first gateway device and a second gateway device. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The access switch includes:

[0016] The first receiving unit is used to receive bidirectional forwarding detection (BFD) message information, wherein the BFD message information originates from the user edge router;

[0017] The first sending unit is configured to send the BFD message information to the first gateway device and the second gateway device, so that the first gateway device establishes a first BFD session with the state information configured as execution state between the user edge router and the first gateway device based on the BFD message information, and to enable the second gateway device to establish a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session;

[0018] The first determining unit is configured to determine that at least one of the first cloud private line links and the second cloud private line link is communicating normally when the access switch does not receive the first closed status message information fed back by the first gateway device. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed status message information is generated when it is determined that the status information of the first BFD session switches from the execution state to the closed state, and the status information of the second BFD session switches from the execution state to the closed state.

[0019] The first processing unit is configured to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links that are communicating normally between the first cloud leased link and the second cloud leased link, and to maintain the first BFD session and the second BFD session.

[0020] In some embodiments, the first processing unit is specifically configured to: when the access switch receives fault information fed back by the first gateway device, determine that the first cloud leased line link communication is abnormal and determine that the second cloud leased line link communication is normal; instruct the first gateway device and the second gateway device to perform a primary / backup identity switch and maintain the first BFD session and the second BFD session; instruct the user edge router to communicate with the cloud leased line gateway through the second cloud leased line link with normal communication.

[0021] In some embodiments, the first BFD session is established between the user edge router and the first gateway device after the first gateway device negotiates the session with the user edge router based on the BFD message information. The negotiated BFD parameter information in the first BFD session is generated by the first gateway device after negotiating the session with the user edge router based on the BFD message information.

[0022] In some embodiments, the cloud private line communication system further includes a database, which is connected to the first gateway device and the second gateway device respectively; the negotiated BFD parameter information in the first BFD session obtained by the second gateway device is obtained by the second gateway device from the database, wherein the negotiated BFD parameter information in the first BFD session in the database is sent by the first gateway device; the second BFD session is established between the user edge router and the second gateway device based on the BFD message information and the negotiated BFD parameter information in the first BFD session obtained by the second gateway device from the database according to the subscription message corresponding to the database.

[0023] In some embodiments, the negotiated BFD parameter information obtained by the second gateway device in the first BFD session is obtained by the second gateway device from the first gateway device; the second BFD session is established between the user edge router and the second gateway device based on the negotiated BFD parameter information obtained by the second gateway device in the first BFD session and the BFD message information and the negotiated BFD parameter information in the first BFD session.

[0024] In some embodiments, the first sending unit is further configured to send the first shutdown status message to the user edge router when the access switch receives the first shutdown status message information fed back by the first gateway device, so as to establish a third BFD session with the status information configured as execution state between the user edge router and the first gateway device based on the first shutdown status message information, and to establish a fourth BFD session with the status information configured as execution state between the user edge router and the second gateway device based on the first shutdown status message information;

[0025] The first determining unit is further configured to determine that at least one of the cloud private line links of the first cloud private line link and the second cloud private line link is communicating normally when the access switch does not receive the second shutdown status message information fed back by the first gateway device. The second shutdown status message information is generated when it is determined that the status information of the third BFD session switches from the execution state to the shutdown state and the status information of the fourth BFD session switches from the execution state to the shutdown state.

[0026] The first processing unit is further configured to instruct the user edge router to communicate with the cloud leased gateway through at least one cloud leased link in the first cloud leased link and the second cloud leased link that are communicating normally, and to maintain the third BFD session and the fourth BFD session.

[0027] In some embodiments, the cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively;

[0028] The first closed state message information is generated by the first gateway device based on the first decision information carrying the closed state issued by the gateway control device. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state.

[0029] The second closed status message information is generated by the first gateway device based on the second decision information carrying the closed status issued by the gateway control device. The second decision information is generated by the gateway control device when it determines that the status information of the third BFD session has switched from the execution state to the closed state, and the status information of the fourth BFD session has switched from the execution state to the closed state.

[0030] In some embodiments, the first sending unit is further configured to send the first shutdown status message information to the user edge router when it receives the first shutdown status message information fed back by the first gateway device, so that the user edge router generates new BFD message information based on the first shutdown status message information;

[0031] The first receiving unit is further configured to receive the new BFD message information;

[0032] The first sending unit is further configured to send the new BFD message information to the first gateway device and the second gateway device, so that after the first gateway device re-negotiates the session with the user edge router based on the new BFD message information, it establishes a third BFD session between the user edge router and the first gateway device with the state information configured as execution state, and so that the second gateway device establishes a fourth BFD session between the user edge router and the second gateway device with the state information configured as execution state based on the new BFD message information and the BFD parameter information negotiated in the third BFD session.

[0033] In some embodiments, the first sending unit is specifically used to: copy the BFD message information and send the copied BFD message information to the first gateway device and the second gateway device according to a preset sending method, wherein the preset sending method includes one of simultaneous sending, separate sending and sequential sending.

[0034] On the other hand, this application provides a gateway device applicable to a first gateway device in a cloud private line communication system. The cloud private line communication system includes a user edge router, an access switch, a cloud private line gateway, and a database. A first gateway device and a second gateway device are configured on the cloud private line gateway. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The database is connected to both the first gateway device and the second gateway device. The gateway device includes:

[0035] The second receiving unit is used to receive bidirectional forwarding detection (BFD) message information sent through the access switch, wherein the BFD message information originates from the user edge router.

[0036] The first establishment unit is used to establish a first BFD session with the state information configured as an execution state between the user edge router and the first gateway device based on the BFD message information.

[0037] The second sending unit is used to send the negotiated BFD parameter information in the first BFD session to the database, so that the second gateway device establishes a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information sent by the access switch and the negotiated BFD parameter information in the first BFD session obtained from the database.

[0038] The second determining unit is configured to determine that at least one of the first cloud private line links and the second cloud private line link is communicating normally when the first gateway device does not obtain the first closed state message information. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state.

[0039] The second processing unit is configured to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links that are communicating normally between the first cloud leased link and the second cloud leased link, and to maintain the first BFD session and the second BFD session.

[0040] In some embodiments, the second processing unit is specifically configured to: when the first gateway device detects fault information, determine that the first cloud leased line link communication is abnormal, and determine that the second cloud leased line link communication is normal; instruct the first gateway device and the second gateway device to perform a primary / backup identity switch, and maintain the first BFD session and the second BFD session; instruct the user edge router to communicate with the cloud leased line gateway through the second cloud leased line link with normal communication.

[0041] In some embodiments, the first gateway device is identified as a primary gateway device, and the second gateway device is identified as a backup gateway device. The second processing unit is further configured to: switch the identity of the first gateway device from the primary gateway device to the backup gateway device, and instruct the identity of the second gateway device to be switched from the backup gateway device to the primary gateway device; the first gateway device maintains the first BFD session, and instruct the second gateway device to maintain the second BFD session.

[0042] In some embodiments, the first establishment unit is specifically configured to: establish a first BFD session between the user edge router and the first gateway device after negotiating a session with the user edge router based on the BFD message information; generate negotiated BFD parameter information in the first BFD session; and configure the status information of the first BFD session to an execution status.

[0043] In some embodiments, when the second gateway device establishes the second BFD session, the status information of the second BFD session is configured as an execution state.

[0044] In some embodiments, the cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively; the gateway device further includes:

[0045] The first reporting unit is used to report the state change information of the first BFD session to the gateway control device when it is detected that the state information of the first BFD session has switched from the execution state to the closed state.

[0046] The first generation unit is configured to generate the first closed state message information if it receives the first decision information carrying the closed state issued by the gateway control device, wherein the first decision information is generated by the gateway control device when it determines that the state information of the first BFD session switches from the execution state to the closed state and the state information of the second BFD session switches from the execution state to the closed state.

[0047] The second sending unit is further configured to send the first closed state message information to the user edge router through the access switch, so as to establish a third BFD session with the state information configured as executed between the user edge router and the first gateway device based on the first closed state message information, and to establish a fourth BFD session with the state information configured as executed between the user edge router and the second gateway device based on the first closed state message information.

[0048] The second determining unit is further configured to determine that at least one of the cloud private line links of the first cloud private line link and the second cloud private line link is communicating normally when the first gateway device does not obtain the second closed state message information. The second closed state message information is generated when it is determined that the state information of the third BFD session switches from the execution state to the closed state and the state information of the fourth BFD session switches from the execution state to the closed state.

[0049] The second processing unit is further configured to instruct the user edge router to communicate with the cloud leased gateway through at least one cloud leased link in the first cloud leased link and the second cloud leased link that are communicating normally, and to maintain the third BFD session and the fourth BFD session.

[0050] In some embodiments, the second sending unit is further configured to: send a deletion instruction to the database, the deletion instruction being used to instruct the deletion of negotiated BFD parameter information in the first BFD session, so that the database responds to the deletion instruction by deleting the negotiated BFD parameter information in the first BFD session in the database, and to cause the second gateway device to respond to the deletion instruction according to the subscription message corresponding to the database by deleting the negotiated BFD parameter information in the first BFD session obtained by the second gateway device.

[0051] In some embodiments, the second processing unit is further configured to: after the first reporting unit reports the closed status of the first BFD session to the gateway control device, if the second receiving unit does not receive the first ruling information carrying the closed status issued by the gateway control device, control the first gateway device to enter a waiting state within the negotiated detection period, the waiting state being used to indicate waiting for execution status message information; in the waiting state, if the second receiving unit continuously receives a preset number of execution status message information, switch the status information of the first BFD session from the closed state to the execution state, the execution status message information originating from the user edge router.

[0052] On the other hand, this application provides a computer-readable storage medium storing a computer program adapted for loading by a processor to execute the cloud private line communication method as described in any of the above embodiments.

[0053] On the other hand, an embodiment of this application provides a computer program product, including computer instructions, which, when executed by a processor, implement the cloud private line communication method as described in any of the above embodiments.

[0054] In this embodiment, the access switch receives BFD message information, which originates from the user edge router. The access switch sends the BFD message information to a first gateway device and a second gateway device, enabling the first gateway device to establish a first BFD session with the state information configured as "executed" between the user edge router and the first gateway device based on the BFD message information, and enabling the second gateway device to establish a second BFD session with the state information configured as "executed" between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session. When the access switch does not receive a first closed state message information from the first gateway device, it determines... At least one of the first and second cloud leased links is communicating normally. The first cloud leased link is the cloud leased link between the user edge router and the first gateway device, and the second cloud leased link is the cloud leased link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session changes from the executed state to the closed state, and the state information of the second BFD session changes from the executed state to the closed state. It instructs the user edge router to communicate with the cloud leased gateway through at least one of the first and second cloud leased links that is communicating normally, and to maintain the first BFD session and the second BFD session. This application embodiment establishes two BFD sessions simultaneously between the user edge router and the first and second gateway devices on the cloud leased line gateway side, providing a dual BFD session mechanism. This ensures the stability of the BFD session during cloud leased line communication. This dual session mechanism ensures that even if one path fails or experiences jitter, the other path can still maintain BFD detection. The dual session mechanism enables seamless upgrade and failover capabilities, allowing seamless switching to the backup gateway device when the primary gateway device fails or requires upgrades or maintenance, without interrupting communication between the user edge router and the cloud leased line gateway, thus guaranteeing the continuity of the BFD session during cloud leased line communication. By establishing two independent BFD session paths, the probability of a single path jitter causing overall BFD session jitter is reduced. Furthermore, when the access switch does not receive the first closed status message from the first gateway device, it can determine that at least one cloud leased line link is communicating normally, thereby instructing the user edge router to communicate through the normally communicating link, improving the efficiency of fault handling. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of a network architecture based on cloud private lines.

[0056] Figure 2 This is a first flowchart illustrating the cloud private line communication method provided in an embodiment of this application.

[0057] Figure 3 This is a schematic diagram of a first application scenario of the cloud private line communication method provided in the embodiments of this application.

[0058] Figure 4 This is a schematic diagram of a second application scenario for the cloud private line communication method provided in the embodiments of this application.

[0059] Figure 5 This is a schematic diagram of a third application scenario for the cloud private line communication method provided in the embodiments of this application.

[0060] Figure 6 This is a schematic diagram of the fourth application scenario of the cloud private line communication method provided in the embodiments of this application.

[0061] Figure 7 This is a second flowchart illustrating the cloud private line communication method provided in the embodiments of this application.

[0062] Figure 8 This is a schematic diagram of the structure of the access switch provided in an embodiment of this application.

[0063] Figure 9 This is a schematic diagram of the gateway device provided in an embodiment of this application. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] This application provides a cloud private line communication method, an access switch, and a gateway device. Exemplarily, the cloud private line communication method of this application can be executed by a computer device, which can be a terminal or a server. The terminal can be a smartphone, tablet, laptop, desktop computer, smart TV, smart speaker, wearable smart device, personal computer (PC), smart vehicle terminal, etc. The terminal can also include a client, which can be a video client, shopping application client, reading application client, browser client, or instant messaging client, etc. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery network (CDN), and big data and artificial intelligence platforms.

[0066] The embodiments of this application can be applied to scenarios such as bidirectional forwarding detection of cloud private lines, cloud computing, and cloud communication.

[0067] First, some of the nouns or terms that appear in the description of the embodiments of this application are explained as follows:

[0068] Cloud computing is a computing model that distributes computing tasks across a large pool of computers, enabling various application systems to access computing power, storage space, and information services as needed. The network providing these resources is called the "cloud." From the user's perspective, resources in the "cloud" appear infinitely scalable, readily available, on-demand, and expandable, with payment based on usage. As a provider of fundamental cloud computing capabilities, a cloud resource pool (referred to as a cloud platform, generally called an Infrastructure as a Service (IaaS) platform) is established. Various types of virtual resources are deployed in the resource pool for external customers to choose from. The cloud resource pool mainly includes: computing devices (virtualized machines containing operating systems), storage devices, and network devices. Logically, a Platform as a Service (PaaS) layer can be deployed on top of the IaaS layer, and a Software as a Service (SaaS) layer can be deployed on top of the PaaS layer. Alternatively, SaaS can be directly deployed on top of IaaS. PaaS is a platform for running software, such as databases and web containers. SaaS refers to various types of business software, such as web portals and bulk SMS senders. Generally, SaaS and PaaS are upper layers compared to IaaS.

[0069] A Customer Edge Router (CER) is a router device deployed at the edge of a user's network, typically used to connect the user's internal network to external networks (such as the Internet or a service provider's network). The CER is responsible for routing the user's internal traffic to the external network and forwarding traffic from the external network to the appropriate destination address within the user's internal network.

[0070] Access switches (Cloud Edge Switches, CES) are typically deployed at the network edge of a cloud service provider to connect the user's network to the cloud service provider's internal network. As the first network device for users accessing the cloud, the CES is responsible for receiving traffic from users and forwarding it to the cloud service provider's internal network for processing.

[0071] An Enterprise Gateway (EGW) is a network device provided by a cloud service provider to establish a dedicated network connection between a user's network and cloud services. EGWs are typically located within the cloud service provider's data center and connected to the user's CER or CES, transmitting data via a dedicated physical connection (such as fiber optic) or a virtual connection (such as a VPN).

[0072] Border Gateway Protocol (BGP) is a protocol for dynamically exchanging routing information between Autonomous Systems (AS). BGP allows ASs to share routing information so they can understand how to reach networks in other ASs. BGP is primarily used for routing between Internet Service Providers (ISPs) and between ISPs and their customers.

[0073] Bidirectional Forwarding Detection (BFD) is a network protocol used to detect faults between two forwarding points, enabling rapid detection of the forwarding connectivity of links or IP routes in a network. BFD provides a general, standardized, media-independent, and protocol-independent fast fault detection mechanism. BFD detects network path connectivity by sending and receiving detection packets, and when a fault is detected, it can quickly notify relevant devices to take appropriate measures (such as rerouting traffic).

[0074] like Figure 1The diagram illustrates a network architecture based on a cloud private line. This architecture may include a Customer Edge Router 110, a Cloud Edge Switch 120, a Master gateway device 130 of the cloud private line gateway, a Standby gateway device 140 of the cloud private line gateway, and a Database 150. The Customer Edge Router 110 is connected to the Master gateway device 130 of the cloud private line gateway via the Cloud Edge Switch 120, and the Customer Edge Router 110 is connected to the Standby gateway device 140 of the cloud private line gateway via the Cloud Edge Switch 120. In cloud private line scenarios, an overlay BFD session is typically established between the user's data center (IDC) and the cloud private line gateway. In the current technical solution, when the customer edge router 110 on the user's IDC side establishes a BGP neighbor relationship and associates with the master gateway 130 of the cloud dedicated line scenario and performs BFD detection, in scenarios such as cloud dedicated line gateway upgrades or cross-backbone network between the cloud dedicated line gateway and access points, the BGP and other routing neighbor states can be stored in a database 150. The standby gateway 140 of the cloud dedicated line gateway can then restore these states by reading the database, thereby achieving rapid failover for the standby gateway 140. However, since BFD sessions have high requirements for real-time performance and sensitivity, directly restoring from the database may exceed the BFD detection time, resulting in BFD neighbor jitter and consequently BFD session jitter.

[0075] like Figure 1As shown, in the traditional technical solution, the BFD session on the master gateway device 130 of the cloud leased line gateway is put into administrative state (Admin Down) operation. That is, the master gateway device 130 sends an administrative state (Admin Down) message to the customer edge router 110, so that the customer edge router 110 stops BFD probing. After the standby gateway device 140 of the cloud leased line gateway restores the BGP neighbor, BFD probing is re-enabled to establish a new BFD session between the customer edge router 110 and the standby gateway device 140. This avoids protocol oscillation caused by the BFD link probing being in a closed state (Down) during the entire master-standby switchover process.

[0076] Traditional solutions rely on sending Admin Down messages during failover to stop BFD probing on the peer. However, if the user has configured BFD to be associated with static routes, Admin Down messages may cause the static routes to fail. Furthermore, this solution can only be used in proactive upgrade scenarios. If the cloud private line gateway's master device (Master 130) malfunctions and undergoes an abnormal failover, it may not have time to send Admin Down messages, resulting in BFD detection failures.

[0077] To address the aforementioned issues, this application proposes a cloud private line communication method. This method maintains an additional BFD session with consistent parameters in a second gateway device (backup gateway device) outside the first gateway device (primary gateway device) of the cloud private line gateway for proxy BFD detection. Multiple copies of the BFD message information are copied and sent to the first and second gateway devices of the cloud private line gateway via multicast from the access switch (CES). Simultaneously establishing BFD sessions with the user edge router (CER) on both the first and second gateway devices ensures that the BFD session is not interrupted during proactive upgrades or abnormal failover of the cloud private line gateway.

[0078] The solutions provided in this application relate to technologies such as cloud private line communication, and are specifically illustrated through the following embodiments. Detailed descriptions are provided below. It should be noted that the order of description of the following embodiments is not intended to limit the priority of the embodiments.

[0079] Please see Figures 2 to 6 , Figure 2This is a first flowchart illustrating the cloud private line communication method provided in an embodiment of this application. Figures 3 to 6 These are schematic diagrams illustrating application scenarios of the cloud private line communication method provided in the embodiments of this application. The method is applicable to a cloud private line communication system, which includes a user edge router, an access switch, and a cloud private line gateway. A first gateway device and a second gateway device are configured on the cloud private line gateway. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway through the access switch, respectively. This method is applied to the access switch and may include the following steps 210 to 240:

[0080] Step 210: The access switch receives bidirectional forwarding detection BFD message information, where the BFD message information originates from the user edge router.

[0081] Please see Figure 3 The diagram illustrates a network architecture for a cloud private line communication system. This system may include a user edge router 310, an access switch 320, a first gateway device 330, a second gateway device 340, and a database 350. The user edge router 310 is connected to the first gateway device 330 of the cloud private line gateway via the access switch 320, and the user edge router 310 is also connected to the second gateway device 340 of the cloud private line gateway via the access switch 320. For example, the first gateway device 330 can be the primary gateway device, and the second gateway device 340 can be the backup gateway device. The first gateway device 330 and the second gateway device 340 can perform primary / backup switching based on a routing protocol.

[0082] The BFD message information received by access switch 320 mainly comes from user edge router 310. This is a step in the BFD protocol used for link or path connectivity detection. When user edge router 310 initiates a BFD session and begins sending BFD message information containing BFD control messages, this BFD message information is received by its downstream access switch 320.

[0083] For example, BFD message information typically includes the following key information:

[0084] Message type: Identifies the type of BFD message, such as control message, echo message, negotiation message, etc.

[0085] Source and destination addresses: These are the IP addresses or MPLS labels of the sender and receiver in the BFD message, used to identify the two communicating parties.

[0086] Version number: Identifies the version of the BFD protocol used.

[0087] Session identifiers, such as local discriminators and remote discriminators, are used to uniquely identify different BFD sessions and ensure correct association and matching of sessions.

[0088] Status information: Indicates the current BFD session status of the sending end, such as down, init, and up. Down indicates the initial state or a link failure; Init indicates that communication with the peer system is possible and the sending end wants to enter the up state; up indicates the execution state, and the session has been successfully established; AdminDown indicates the session is in an administrative down state.

[0089] Detection interval (Desired and Required Min TX Interval / RX Interval): This is the frequency at which BFD messages are sent. It represents the minimum sending interval desired by the sender and the minimum receiving interval required by the receiver. These two parameters are negotiated during the session establishment phase.

[0090] Detection Multiplier: The maximum number of times a response message is not received. If this number is exceeded, the link is considered to be in failure.

[0091] In addition, BFD message information can also include authentication information to support the authentication function of BFD sessions.

[0092] Step 220: The access switch sends BFD message information to the first gateway device and the second gateway device, so that the first gateway device establishes a first BFD session with the state information configured as "executed" between the user edge router and the first gateway device based on the BFD message information, and so that the second gateway device establishes a second BFD session with the state information configured as "executed" between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session.

[0093] In step 220, the access switch sends the received BFD message information to the first gateway device and the second gateway device. The first gateway device can establish a first BFD session with its state information configured as "executed" between the user edge router and the first gateway device based on the BFD message information. Similarly, the second gateway device can also establish a second BFD session with its state information configured as "executed" between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session.

[0094] For example, the BFD parameters negotiated in the first BFD session may include, but are not limited to, source address, destination address, transmission time interval, reception time interval, and detection multiplier. In addition, the following parameters may also be included:

[0095] Detection Modes: BFD supports both single-hop and multi-hop detection modes. Single-hop detection is suitable for IP connectivity testing between directly connected systems, while multi-hop detection can detect whether all intermediate nodes between two systems are functioning correctly.

[0096] Detection time interval: This refers to the time interval between the two parties in a BFD session exchanging control messages. If no control message is received from the other party within the detection time, the connection is considered unusable.

[0097] Minimum detection time: This refers to the minimum amount of time the system must wait after a fault is detected to ensure that the fault has indeed occurred and recovery operations are required.

[0098] Maximum detection time: This refers to the maximum amount of time the system will wait after a fault is detected. If no fault is detected within this time, the connection is considered normal.

[0099] Detection multiplier: This refers to the amount of time the system waits after a fault is detected, multiplied by this multiplier, to determine the time interval for the next attempt to re-establish the connection.

[0100] Diagnostic information: This is information used for troubleshooting, such as error codes and error descriptions.

[0101] Checksum: Used to verify the integrity and accuracy of BFD message information.

[0102] Probe mode (Asynchronous or Demand): In asynchronous mode, both ends continuously send messages; while in demand mode, messages are sent or responded to only when needed.

[0103] Step 220 sends BFD message information to the first and second gateway devices, enabling the user edge router to simultaneously establish two BFD sessions with their status information configured as "executed" on the cloud leased line gateway side. This provides a dual BFD session mechanism, ensuring that even if one path fails or experiences jitter, the other path can still maintain BFD detection. The dual session mechanism enables seamless upgrade and failover capabilities, allowing seamless switching to the backup gateway device when the primary gateway device fails or requires upgrades or maintenance, without interrupting communication between the user edge router and the cloud leased line gateway. By establishing two independent BFD session paths, the probability of a single path jitter causing overall BFD session jitter is reduced.

[0104] In some embodiments, the access switch sends BFD message information to the first gateway device and the second gateway device, including:

[0105] The access switch copies the BFD message information and sends the copied BFD message information to the first gateway device and the second gateway device according to a preset sending method. The preset sending method includes one of simultaneous sending, separate sending, and sequential sending.

[0106] In this process, after receiving a BFD message from the user edge router, the access switch uses a replication mechanism to copy the original message into multiple copies, with each copy maintaining the same content and format as the original. The purpose of this replication operation is to ensure that both the first and second gateway devices (i.e., the primary and backup gateway devices) receive the same BFD session initialization information, thereby enabling them to independently establish BFD sessions.

[0107] The copied BFD message information can be sent to the target gateway device according to different strategies. Preset sending methods can be flexibly configured; common ones include the following:

[0108] Simultaneous transmission: The copied BFD message information is sent to the first gateway device and the second gateway device at the same time, ensuring that the two receive the message almost synchronously.

[0109] Send separately: BFD message information is sent to each gateway device individually in sequence. Although not simultaneously, each gateway device will start the corresponding BFD session establishment process after receiving the message.

[0110] Sequential transmission: Data is sent to each gateway device sequentially according to a predetermined priority order, for example, first to the primary gateway device, then to the backup gateway devices. This method is suitable for certain network environments, such as when the connection bandwidth between two gateway devices is limited.

[0111] like Figure 3As shown, in practical applications, a second BFD session is established on the second gateway device 340 (backup gateway device). Access switch 320 can be configured with multicast functionality to automatically copy and broadcast a single BFD message sent from the user edge router 310 in the IDC direction to multiple specified destinations (such as the first gateway device 330 and the second gateway device 340). For example, configuring multicast on access switch 320 can copy the BFD message information sent by the user edge router 310 in the IDC direction to two copies, sending them to the first gateway device 330 and the second gateway device 340 of the cloud dedicated line gateway respectively. The first gateway device 330 negotiates a session with the user edge router 310 and successfully establishes a first BFD session. The second gateway device 340 generates a second BFD session with a status information directly configured as "up" based on the negotiated BFD parameter information from the first BFD session of the first gateway device 330. This achieves the effect of simultaneously establishing two BFD sessions between the primary and backup gateway devices on the cloud dedicated line gateway side and the user edge router 310 on the IDC side.

[0112] In this process, the first gateway device 330 (the primary gateway device) negotiates a normal session with the user edge router 310 based on the received BFD message information, forming a first BFD session. The second gateway device 340 (the backup gateway device) then uses the BFD parameters negotiated by the first gateway device to simulate or forcibly set its own BFD session state to "up." This is called a proxy mechanism or fast switchover preparation. It does not require actually performing the complete BFD negotiation process but pre-prepares the second BFD session so that traffic can be quickly switched during cloud private line gateway upgrades or network failures, ensuring service continuity. Because the second gateway device 340 generates a second BFD session with a directly configured state of "up" based on the negotiated BFD parameters from the first BFD session of the first gateway device 330, even if the second gateway device 340 does not directly negotiate a session with the user edge router 310, it can ensure that the state of the second BFD session of the second gateway device 340 is consistent with the state of the first BFD session of the first gateway device 330.

[0113] Besides replication, BFD messages used for transmission may also be forwarded or the original BFD messages may be sent separately. These methods depend on the specific network environment and requirements.

[0114] In summary, by processing and sending BFD message information, it can be ensured that the primary and backup gateway devices on the cloud private line gateway side and the user edge router on the IDC side can establish two BFD sessions simultaneously, thereby achieving high availability and rapid fault detection.

[0115] In some embodiments, the first BFD session is established between the user edge router and the first gateway device after the first gateway device negotiates the session with the user edge router based on the BFD message information. The negotiated BFD parameter information in the first BFD session is generated by the first gateway device after negotiating the session with the user edge router based on the BFD message information.

[0116] In some embodiments, the cloud private line communication system further includes a database, which is connected to the first gateway device and the second gateway device respectively; the negotiated BFD parameter information in the first BFD session obtained by the second gateway device is obtained by the second gateway device from the database, wherein the negotiated BFD parameter information in the first BFD session in the database is sent by the first gateway device;

[0117] The second BFD session is established between the user edge router and the second gateway device based on the BFD message information and the negotiated BFD parameters from the first BFD session obtained by the second gateway device from the database according to the corresponding subscription message.

[0118] Please see Figure 4 The diagram shows another network architecture of a cloud private line communication system. This system may include a user edge router 410, an access switch 420, a first gateway device 430, a second gateway device 440, a database 450, and a gateway controller 460. The user edge router 410 is connected to the first gateway device 430 of the cloud private line gateway via the access switch 420, and is also connected to the second gateway device 440 via the access switch 420. The gateway controller 460 is connected to both the first gateway device 430 and the second gateway device 440.

[0119] For example, when BFD detection is enabled, the session establishment process may include the following:

[0120] 1. Gateway control device 460 sends BFD configuration information to both the first gateway device 430 and the second gateway device 440. The sent BFD configuration information consists of local parameters (static parameters), such as the minimum transmission interval, detection period, source address, and destination address information. Specifically, the BFD configuration information sent to the first gateway device 430 is its local parameter, and the BFD configuration information sent to the second gateway device 440 is its local parameter. While gateway control device 460 sends BFD configuration information (local parameters) to both the first gateway device 430 and the second gateway device 440, only the first gateway device 430 negotiates its local parameters using the peer parameters; the second gateway device 440 does not need to negotiate.

[0121] 2. The BFD configuration information is made effective in the first gateway device 430, and a timer is started. The BFD configuration information is not processed in the second gateway device 440.

[0122] 3. Access switch 420 multicasts and copies the BFD message information twice. Access switch 420 copies the BFD message information twice and sends it to the first gateway device 430 and the second gateway device 440 of the cloud private line gateway respectively.

[0123] 4. The user edge router 410 and the first gateway device 430 conduct session negotiation and establish a first BFD session in an active state. During the negotiation process, the first gateway device 430, based on the BFD message information (peer parameters) sent by the user edge router 410 and the BFD configuration information (local parameters) sent by the gateway control device 460, negotiates a session with the user edge router 410, establishes a first BFD session between them, generates mutually agreed-upon negotiated BFD parameter information for the first BFD session, and configures the status information of the first BFD session to active state, indicating that the session is active and is detecting link status. The second gateway device 440 does not process session negotiation messages; therefore, only the first gateway device 430 normally processes the BFD message information during the session negotiation process.

[0124] 5. The first gateway device 430 sends the negotiated BFD parameter information from the first BFD session to the database 450. For example, after the first gateway device 430 successfully negotiates the first BFD session and configures the up state, the first gateway device 430 writes the negotiated BFD parameter information of the first BFD session (up session), such as the source address, destination address, transmission time interval, reception time detection, and detection multiplier, into the database 450. This action ensures that other network components, such as the second gateway device 440, can obtain accurate BFD parameter information as needed.

[0125] 6. The second gateway device 440 obtains the negotiated BFD parameter information from the database 450 based on the subscription message corresponding to the database 450.

[0126] 7. A second BFD session in an executing state is established between the user edge router 410 and the second gateway device 440. Specifically, the second gateway device 440 subscribes to messages in the database 450, obtains the negotiated BFD parameter information from the first BFD session, restores a second BFD session with identical parameters based on the obtained BFD parameter information, and directly configures the state information of the second BFD session to "up," starting to send and receive relevant BFD message information, thus directly restoring an "up" state second BFD session. After obtaining the negotiated BFD parameter information from the first BFD session, the second gateway device 440 establishes a second BFD session with the user edge router 410 using the same parameters, but does not perform the actual negotiation steps. Instead, it directly applies the parameter configuration obtained from the database 450, and the established second BFD session is also set to the executing state (up state). Although it does not go through the regular BFD session negotiation phase, because it uses parameters completely identical to the first BFD session, it ensures that the second gateway device 440 can seamlessly take over traffic and avoid service interruption in the event of a failure of the first gateway device 430.

[0127] The session negotiation process is a three-way handshake. During this process, the communicating parties negotiate the corresponding parameters, and the session state changes to Up. This means that before the session is established, BFD control messages are sent periodically at 1-second intervals to reduce message traffic. Once the session is established, BFD control messages are sent at the negotiated intervals to achieve rapid detection.

[0128] The state machine changes: The BFD state machine transmits state change information through the State field of the BFD message. The network architecture based on the cloud private line drives state changes based on its local session state and the received BFD messages from the peer. For example, if a down packet is received, the state machine will jump from the down state to the init state; if an init packet is received, it may further jump to the up or down state, depending on subsequent interactions.

[0129] For example, the process of session negotiation between the user edge router 410 and the first gateway device 430 may include the following steps:

[0130] 1) User edge router 410 and first gateway device 430 start BFD, each with an initial state of "down", and send BFD message information with a state of "down";

[0131] 2) When the first gateway device 430 receives a BFD message with a status of "down", its local status switches to "init" and sends a BFD message with a status of "init" to the user edge router 410. In this case, after the local BFD status of the first gateway device 430 is "init", it does not process any BFD message with a status of "down" when it receives it.

[0132] 4) When the first gateway device 430 receives a BFD message with a status of "init" from the user edge router 410, its local status switches to "up" and it sends a BFD message with a status of "up" to the user edge router 410. After the local BFD status of the first gateway device 430 is "up", it does not process any BFD message with a status of "init" when it receives it.

[0133] 5) The BFD state change process of the user edge router 410 is the same as above: When the user edge router 410 receives a BFD message with a state of "down" sent by the first gateway device 430, its local state switches to "init" and sends a BFD message with a state of "init" to the first gateway device 430; When the user edge router 410 receives a BFD message with a state of "init" sent by the first gateway device 430, its local state switches to "up" and sends a BFD message with a state of "up" to the first gateway device 430.

[0134] 6) After the user edge router 410 and the first gateway device 430 change from the state "down" to "init", a timeout timer will be started. The purpose of this timer is to prevent the local state from being blocked at "init" (the connection between the two ends may be lost at this time, and the session cannot be established normally). If no BFD message with the state "init / up" is received within the specified time, the state will automatically switch back to "down".

[0135] 7) If both ends are in the up state, the session has been successfully established.

[0136] In some embodiments, the negotiated BFD parameter information obtained by the second gateway device in the first BFD session is obtained by the second gateway device from the first gateway device;

[0137] The second BFD session is established between the user edge router and the second gateway device by the second gateway device obtaining the negotiated BFD parameter information from the first BFD session and based on the BFD message information and the negotiated BFD parameter information from the first BFD session.

[0138] For example, the second gateway device can directly communicate with the first gateway device. The second gateway device can directly obtain the BFD parameter information negotiated in the first BFD session. Based on the BFD message information and the negotiated BFD parameters in the first BFD session, a second BFD session is established between the user edge router and the second gateway device. The state information of the second BFD session is configured to be in the up state. This direct communication method means that information can be quickly exchanged between the two gateway devices, reducing communication latency and improving the overall network response speed. It avoids the need for forwarding through other intermediate devices, thereby improving data transmission efficiency.

[0139] For example, the second gateway device needs to obtain the BFD parameter information successfully negotiated between the first gateway device and the user edge router. Typically, this can be accomplished through some network synchronization mechanism or direct communication. For instance, the second gateway device can obtain this parameter information directly from the first gateway device, or indirectly through network management protocols, log transmission, backup configuration files, etc.

[0140] After obtaining the negotiated BFD parameters from the first BFD session, the second gateway device does not actually renegotiate the BFD session with the user edge router. Instead, it directly uses the negotiated BFD parameters from the first BFD session to establish a new BFD session (i.e., the second BFD session). Although this second BFD session does not undergo a complete handshake negotiation process, it is configured in an "up" state based on known good parameters, meaning that even without actual BFD packet exchange, the link is considered to be in normal operation. Based on the acquired BFD parameters, the second gateway device can quickly establish a second BFD session with the user edge router. Since these parameters have been pre-negotiated, the newly established session can directly enter the execution (up) state. This not only speeds up the session establishment process but also ensures consistency of state information between the two sessions, thereby enhancing network stability and reliability. When the first gateway device fails or requires maintenance, the second gateway device is ready to take over the BFD session. Since the second BFD session is already in the up state, it can seamlessly continue to detect network link status, ensuring that the network's fault detection and notification functions are not affected when the primary gateway device is unavailable.

[0141] Step 230: When the access switch does not receive the first closed status message information from the first gateway device, it determines that at least one of the first cloud private line links and the second cloud private line links is communicating normally. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed status message information is generated when it is determined that the status information of the first BFD session changes from the execution state to the closed state, and the status information of the second BFD session changes from the execution state to the closed state.

[0142] In a cloud private line environment, two BFD sessions (a first BFD session and a second BFD session) are deployed, corresponding to the first cloud private line link and the second cloud private line link, respectively. These two BFD sessions are used to monitor the communication status of the two cloud private line links in real time, ensuring the stability and reliability of data transmission.

[0143] Specifically, when both the first and second BFD sessions switch from the executing state to the closed state, a first closed state message is generated. This indicates that both cloud private line links have failed and cannot transmit data normally.

[0144] If the access switch does not receive a first shutdown status message within the predetermined time, it means that at least one BFD session did not detect a link anomaly, confirming that at least one of the first and second cloud leased line links is communicating normally. This is because a first shutdown status message is only generated if both cloud leased line links fail.

[0145] Step 240: Instruct the user edge router to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and maintain the first BFD session and the second BFD session.

[0146] Step 240 involves selecting at least one of the two cloud leased line links that is functioning normally to maintain communication between the user edge router and the cloud leased line gateway, while simultaneously maintaining the continuity of the BFD session. This step is a critical part of network fault recovery and high availability assurance.

[0147] In cloud private line environments, Border Gateway Protocol (BGP) combined with Bidirectional Forwarding Detection (BFD) is typically used to improve network stability and reliability. BGP is used to exchange routing information between different autonomous systems, while BFD is used to quickly detect any link failures.

[0148] To achieve high availability, two physically independent cloud leased line links can be configured, one as the primary link and the other as a backup link. When the primary link fails, the system can quickly switch to the backup link to minimize network downtime. With the help of BGP, when one link fails, the user edge router can dynamically update its routing table to ensure that packets are transmitted through the other working link. This dynamic routing update helps maintain network stability and connectivity.

[0149] Maintaining the first and second BFD sessions means that health monitoring of these two links will not stop even after a path switch occurs. The BFD session, through its rapid fault detection mechanism, continuously verifies the connectivity of each link, providing real-time link status feedback.

[0150] In some embodiments, instructing the user edge router to communicate with the cloud leased gateway via at least one of the first and second cloud leased links that are in normal communication, and to maintain the first BFD session and the second BFD session, includes:

[0151] When the access switch receives the fault information from the first gateway device, it determines that the first cloud private line link is abnormal and that the second cloud private line link is normal.

[0152] Instruct the first gateway device and the second gateway device to perform a primary / backup identity switch, and maintain the first BFD session and the second BFD session;

[0153] Instruct the user edge router to communicate with the cloud leased line gateway through the second cloud leased line link where communication is normal.

[0154] When the access switch receives fault information from the first gateway device, this is part of the link health detection mechanism. This indicates that there is a communication problem on the first cloud private line link, possibly due to a line fault, equipment failure, or other network issues. In this situation, a rapid response is required to avoid service interruption.

[0155] In this process, based on step 230 which confirms that at least one of the first and second cloud leased line links is communicating normally, in step 240, while determining that the first cloud leased line is communicating abnormally based on the fault information of the first gateway device, it can further confirm that the second cloud leased line is communicating normally based on step 230. Then, the first and second gateway devices are instructed to switch over their primary / backup roles. This switching mechanism ensures that even if the primary link fails, the backup link can immediately take over the traffic, guaranteeing uninterrupted data transmission. Maintaining the first and second BFD sessions is crucial in this process because it allows for continuous monitoring of the status of both links, enabling rapid identification of any new faults even after the primary / backup switchover.

[0156] Once the primary / backup switchover is complete, the user edge router will be instructed to transmit data via the currently functioning second cloud leased line link. This immediate path adjustment is based on real-time analysis and decision-making regarding network status, ensuring that communication between the user edge router and the cloud leased line gateway is not interrupted due to a link failure.

[0157] Even after a switchover, the first and second BFD sessions must be maintained to continuously monitor the communication status of the two links. Once the original faulty link restores normal communication through upgrade or repair operations, the link communication status can be reassessed using the two maintained BFD sessions, and a primary / backup switchover can be performed again if necessary to restore the optimal configuration.

[0158] In some embodiments, the method further includes:

[0159] When the access switch receives the first shutdown state message information fed back by the first gateway device, it sends the first shutdown state message information to the user edge router to establish a third BFD session with the state information configured as execution between the user edge router and the first gateway device based on the first shutdown state message information, and to establish a fourth BFD session with the state information configured as execution between the user edge router and the second gateway device based on the shutdown state message information.

[0160] When the access switch does not receive the second closed status message information from the first gateway device, it is determined that the communication between the first cloud private line link and at least one of the second cloud private line links is normal. The second closed status message information is generated when it is determined that the status information of the third BFD session changes from the execution state to the closed state, and the status information of the fourth BFD session changes from the execution state to the closed state.

[0161] The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are in normal communication between the first cloud leased line link and the second cloud leased line link, and to maintain the third and fourth BFD sessions.

[0162] When the access switch receives the first closed state message from the first gateway device, it indicates that both initially established BFD sessions are in the closed state. At this time, the first closed state message needs to be forwarded to the user edge router so that the user edge router and the first gateway device enter a renegotiation state to establish a new BFD session: so that the user edge router establishes a new BFD session with the first gateway device based on the received first closed state message, called the third BFD session, and its state information is configured as the execution state; at the same time, so that the user edge router establishes another new BFD session with the second gateway device, called the fourth BFD session, and its state information is also configured as the execution state.

[0163] Then, if the access switch does not receive the second shutdown status message from the first gateway device, it can be determined that at least one of the first and second cloud leased line links is communicating normally. The second shutdown status message is generated when the status information of both newly established BFD sessions (the third and fourth BFD sessions) switches from the executing state to the shutdown state. Then, the user edge router is instructed to transmit data through at least one normally communicating cloud leased line link and maintain the newly established third and fourth BFD sessions. These steps are part of the network fault detection and recovery strategy, ensuring that the network can quickly restore normal communication in the event of a link failure, thus guaranteeing the continuity and stability of cloud leased line communication.

[0164] In some embodiments, the cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively;

[0165] The first closed state message information is generated by the first gateway device based on the first decision information carrying the closed state issued by the gateway control device. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session has switched from the execution state to the closed state, and the state information of the second BFD session has switched from the execution state to the closed state.

[0166] The second closed status message is generated by the first gateway device based on the second decision information carrying the closed status issued by the gateway control device. The second decision information is generated by the gateway control device when it determines that the status information of the third BFD session has switched from the execution state to the closed state, and the status information of the fourth BFD session has switched from the execution state to the closed state.

[0167] In the cloud private line communication system, to ensure communication stability and rapid fault recovery between the user edge router and the cloud private line gateway, dual BFD sessions are used to detect link status. The network architecture of the cloud private line communication system also introduces gateway control devices to assist in managing these BFD sessions, thereby optimizing the fault detection and recovery process.

[0168] Please see Figure 5 The diagram shows another network architecture of a cloud private line communication system. This system may include a user edge router 510, an access switch 520, a first gateway device 530, a second gateway device 540, a database 550, and a gateway control device 560. The user edge router 510 is connected to the first gateway device 530 of the cloud private line gateway via the access switch 520, and is also connected to the second gateway device 540 of the cloud private line gateway via the access switch 520. The gateway control device 560 is connected to both the first gateway device 530 and the second gateway device 540.

[0169] like Figure 5As shown, when a link down is detected, due to the existence of two BFD sessions, there may be inconsistencies in their states. In this case, both the first gateway device 530 and the second gateway device 540 need to simultaneously report the state change information of the BFD sessions to the gateway control device 560 for adjudication. During the period before the gateway control device 560 makes its adjudication, the first gateway device 530, which is in a down state, will not send a shutdown (down) state message to prevent the BFD session of the user edge router 510 on the peer IDC side from being switched to a down state. When gateway control device 560 receives two down status messages—that is, after receiving the status change information of the first BFD session changing from the executing state to the closed state, and the status change information of the second BFD session changing from the executing state to the closed state—it sends a first decision message carrying the closed (down) status to first gateway device 530. At this time, first gateway device 530 sends a first closed (down) status message to the peer user edge router 510 through access switch 520, so that user edge router 510 and first gateway device 530 enter a renegotiation state to establish new BFD sessions (third BFD session and fourth BFD session) through renegotiation. At the same time, it can delete the negotiated BFD parameter information of the first BFD session stored in database 550. After second gateway device 540 responds to the deletion of BFD parameter information, it deletes its local BFD parameter information and local second BFD session. At this point, the entire network architecture returns to the state of waiting for first gateway device 530 to negotiate sessions. When only one device's BFD session state information switches to the down state, it may only be a brief, localized link jitter. In this case, the gateway control device 560 will not send an adjudication message carrying the down state. The device will enter a waiting state for up packets. If no adjudication message carrying the down state is received within the negotiated detection period, but BFD packets with the up state information are received consecutively within the corresponding detection period, it indicates that the other BFD session is in a normal state. At this time, the BFD session is directly restored to the up state, and detection continues. For example, when only the first BFD session's state information is available and it switches to the down state, the gateway control device 560 will not send the first adjudication message carrying the down state. The first gateway device will enter a waiting state for up packets. If no first adjudication message carrying the down state is received within the negotiated detection period, but BFD packets with the up state information are received consecutively within the corresponding detection period, it indicates that the second BFD session is in a normal state. At this time, the first BFD session is directly restored to the up state, and detection continues.

[0170] In some embodiments, when the access switch receives a first shutdown state message from the first gateway device, it sends the first shutdown state message to the user edge router to establish a third BFD session between the user edge router and the first gateway device based on the first shutdown state message, and to establish a fourth BFD session between the user edge router and the second gateway device based on the first shutdown state message, including:

[0171] When the access switch receives the first shutdown status message from the first gateway device, it sends the first shutdown status message to the user edge router so that the user edge router can generate a new BFD message based on the first shutdown status message.

[0172] The access switch receives new BFD message information;

[0173] The access switch sends new BFD message information to the first gateway device and the second gateway device, so that the first gateway device can re-negotiate the session with the user edge router based on the new BFD message information and establish a third BFD session between the user edge router and the first gateway device with the state information configured as "executed". The second gateway device can establish a fourth BFD session between the user edge router and the second gateway device with the state information configured as "executed" based on the new BFD message information and the BFD parameter information negotiated in the third BFD session.

[0174] Please see Figure 5When the gateway control device 560 receives the status change information of the first BFD session switching from the execution state to the closed state, and the status change information of the second BFD session switching from the execution state to the closed state, it sends a decision information carrying the closed (down) state to the first gateway device 530. At this time, the first gateway device 530 sends the closed (down) state message information to the peer user edge router 510 through the access switch 520 and enters the renegotiation state. The renegotiation process is as follows: When the access switch 520 receives the shutdown status message from the first gateway device 530, it sends the shutdown status message to the user edge router 510, so that the user edge router 510 generates a new BFD message based on the shutdown status message; the access switch 520 receives the new BFD message; the access switch 520 sends the new BFD message to the first gateway device 530 and the second gateway device 540, so that the first gateway device 530 renegotiations the session with the user edge router 510 based on the new BFD message, and establishes a third BFD session between the user edge router 510 and the first gateway device 530; and the second gateway device 540 establishes a fourth BFD session between the user edge router 510 and the second gateway device 540 based on the new BFD message and the BFD parameter information negotiated in the third BFD session; wherein, the status information of the third BFD session is configured as the execution state, and the status information of the fourth BFD session is configured as the execution state.

[0175] This embodiment monitors the status of the first and second gateway devices in real time through an access switch, and immediately triggers a fault notification process upon receiving a first closed state message. The access switch forwards the first closed state message to the user edge router, prompting the user edge router to generate a new BFD message to initiate a new session negotiation process. After receiving the new BFD message from the user edge router, the access switch re-distributes this information to the first and second gateway devices, guiding them to re-establish the BFD session. Based on the newly received BFD message, the first gateway device conducts a new round of session negotiation with the user edge router, and on this basis, builds a new third BFD session, ensuring that the link state detection in this direction returns to normal. The second gateway device, through the newly received BFD parameter information negotiated in the third BFD session, can quickly establish a fourth BFD session with the user edge router without having to re-negotiate the complete parameters, thus improving the speed and efficiency of fault recovery. This embodiment effectively realizes automatic triggering of BFD session reconstruction in the event of a fault, reducing the need for manual intervention, enhancing the network's self-healing capabilities, and ensuring the high reliability and rapid failover of the cloud private line service.

[0176] Please see Figure 6 The diagram shows another network architecture of a cloud private line communication system. This system may include a user edge router 610, an access switch 620, a first gateway device 630, a second gateway device 640, a database 650, and a gateway control device 660. The user edge router 610 is connected to the first gateway device 630 of the cloud private line gateway via the access switch 620, and is also connected to the second gateway device 640 of the cloud private line gateway via the access switch 620. The gateway control device 660 is connected to both the first gateway device 630 and the second gateway device 640.

[0177] like Figure 6 As shown, by configuring the second gateway device 640 to handle the switching, when the cloud private line gateway performs a primary / backup switch, it is not necessary to send a BFD Admin Down message to the peer. Figure 6 As shown, during primary / standby switchover, the BFD sessions remain unchanged. Specifically, during the primary / standby switchover process, only the routing protocol needs to perform the primary / standby switchover. The BFD sessions on the first gateway device 630 and the second gateway device 640 only need to remain unchanged, continuing to maintain two BFD sessions in the up state, thus simplifying the BFD processing logic during the primary / standby switchover process.

[0178] All of the above technical solutions can be combined in any way to form optional embodiments of this application, and will not be described in detail here.

[0179] In this embodiment, the access switch receives BFD message information, which originates from the user edge router. The access switch sends the BFD message information to a first gateway device and a second gateway device, enabling the first gateway device to establish a first BFD session with the state information configured as "executed" between the user edge router and the first gateway device based on the BFD message information, and enabling the second gateway device to establish a second BFD session with the state information configured as "executed" between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session. When the access switch does not receive a first closed state message information from the first gateway device, it determines... At least one of the first and second cloud leased links is communicating normally. The first cloud leased link is the cloud leased link between the user edge router and the first gateway device, and the second cloud leased link is the cloud leased link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session changes from the executed state to the closed state, and the state information of the second BFD session changes from the executed state to the closed state. It instructs the user edge router to communicate with the cloud leased gateway through at least one of the first and second cloud leased links that is communicating normally, and to maintain the first BFD session and the second BFD session. This application embodiment establishes two BFD sessions simultaneously between the user edge router and the first and second gateway devices on the cloud leased line gateway side, providing a dual BFD session mechanism. This ensures the stability of the BFD session during cloud leased line communication. This dual session mechanism ensures that even if one path fails or experiences jitter, the other path can still maintain BFD detection. The dual session mechanism enables seamless upgrade and failover capabilities, allowing seamless switching to the backup gateway device when the primary gateway device fails or requires upgrades or maintenance, without interrupting communication between the user edge router and the cloud leased line gateway, thus guaranteeing the continuity of the BFD session during cloud leased line communication. By establishing two independent BFD session paths, the probability of a single path jitter causing overall BFD session jitter is reduced. Furthermore, when the access switch does not receive the first closed status message from the first gateway device, it can determine that at least one cloud leased line link is communicating normally, thereby instructing the user edge router to communicate through the normally communicating link, improving the efficiency of fault handling.

[0180] Please see Figure 7 , Figure 7This is a second flowchart illustrating the cloud private line communication method provided in this application embodiment. The method is applicable to a cloud private line communication system, which includes a user edge router, an access switch, a cloud private line gateway, and a database. The cloud private line gateway is configured with a first gateway device and a second gateway device. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The database is connected to both the first gateway device and the second gateway device. The method is applied to the first gateway device and may include steps 710 to 750:

[0181] Step 710: The first gateway device receives bidirectional forwarding detection (BFD) message information sent through the access switch, wherein the BFD message information originates from the user edge router.

[0182] Step 720: The first gateway device establishes a first BFD session between the user edge router and the first gateway device based on the BFD message information, with the state information configured as the execution state.

[0183] Step 730: The first gateway device sends the negotiated BFD parameter information from the first BFD session to the database, so that the second gateway device can establish a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information sent by the access switch and the negotiated BFD parameter information from the first BFD session obtained from the database.

[0184] Please see Figure 4 The first gateway device 430 receives BFD message information sent by the access switch 420, which mainly originates from the user edge router 410. When the user edge router 410 initiates a BFD session and begins sending BFD message information containing BFD control messages, these BFD message messages are received by its downstream access switch 420 and forwarded to the first gateway device 430 and the second gateway device 440. The first gateway device 430 establishes a first BFD session between the user edge router 410 and the second gateway device 440 based on the BFD message information. The first gateway device 430 sends the negotiated BFD parameter information from the first BFD session to the database 450, so that the second gateway device 440 establishes a second BFD session between the user edge router 410 and the second gateway device 440 based on the BFD message information sent by the access switch 420 and the negotiated BFD parameter information from the first BFD session obtained from the database 450.

[0185] In some embodiments, the first gateway device establishes a first BFD session with state information configured as being in an executing state between the user edge router and the first gateway device based on BFD message information, including:

[0186] After the first gateway device negotiates a session with the user edge router based on BFD message information, a first BFD session is established between the user edge router and the first gateway device.

[0187] Generate the negotiated BFD parameter information for the first BFD session;

[0188] Configure the status information of the first BFD session to be in execution state.

[0189] Please see Figure 4 The first gateway device 430 negotiates a session with the user edge router 410 and establishes a first BFD session in an active state. During the negotiation process, based on the BFD message information (peer parameters) sent by the user edge router 410 and the BFD configuration information (local parameters) sent by the gateway control device 460, the first gateway device 430 negotiates a session with the user edge router 410, establishes a first BFD session between them, generates mutually agreed-upon negotiated BFD parameter information for the first BFD session, and configures the state information of the first BFD session to active state, indicating that the session is active and is detecting link status. The second gateway device 440 does not process session negotiation messages; therefore, only the first gateway device 430 normally processes the BFD message information during the session negotiation process.

[0190] Then, the first gateway device 430 sends the negotiated BFD parameter information from the first BFD session to the database 450. For example, after the first gateway device 430 successfully negotiates the first BFD session and configures the up state, it writes the negotiated BFD parameter information, such as the source address, destination address, transmission time interval, reception time detection, and detection multiplier, into the database 450. This action ensures that other network components, such as the second gateway device 440, can obtain accurate BFD parameter information as needed.

[0191] Specifically, when the second gateway device establishes the second BFD session, the status information of the second BFD session is configured as the execution status.

[0192] Please see Figure 4The second gateway device 440 retrieves the negotiated BFD parameter information from the database 450 based on the subscription message corresponding to the database 450. The second gateway device 440 establishes a second BFD session in execution state between the user edge router 410 and the second gateway device 440. Specifically, the second gateway device 440 retrieves the negotiated BFD parameter information from the database 450 by subscribing to messages from the database 450, restores a second BFD session with consistent parameters based on the obtained BFD parameter information, directly configures the state information of the second BFD session to the up state, and begins sending and receiving relevant BFD message information, directly restoring an up-state second BFD session. After obtaining the negotiated BFD parameter information from the first BFD session, the second gateway device 440 establishes a second BFD session with the user edge router 410 based on the same parameters. However, it does not perform the actual negotiation steps, but directly applies the parameter configuration obtained from the database 450. The established second BFD session is also set to the execution state (up state). Although it does not go through the regular BFD session negotiation stage, it can ensure that the second gateway device 440 can seamlessly take over the traffic and avoid service interruption when the first gateway device 430 fails, because it uses parameters that are completely consistent with the first BFD session.

[0193] Step 740: When the first gateway device does not obtain the first closed state message information, it is determined that at least one of the first cloud private line links and the second cloud private line links is communicating normally. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state.

[0194] In a cloud private line environment, two BFD sessions (a first BFD session and a second BFD session) are deployed, corresponding to the first cloud private line link and the second cloud private line link, respectively. These two BFD sessions are used to monitor the communication status of the two cloud private line links in real time, ensuring the stability and reliability of data transmission.

[0195] Specifically, when both the first and second BFD sessions switch from the executing state to the closed state, a first closed state message is generated. This indicates that both cloud private line links have failed and cannot transmit data normally.

[0196] If the first gateway device does not receive the first shutdown status message within the predetermined time, it means that at least one BFD session did not detect a link anomaly, and it can be determined that at least one of the first and second cloud leased line links is communicating normally. This is because the first shutdown status message is only generated if both cloud leased line links fail.

[0197] Step 750: Instruct the user edge router to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and maintain the first BFD session and the second BFD session.

[0198] Step 750 involves selecting at least one of the two cloud leased line links that is functioning normally to maintain communication between the user edge router and the cloud leased line gateway, while simultaneously maintaining the continuity of the BFD session. This step is a critical part of network fault recovery and high availability assurance.

[0199] In cloud private line environments, Border Gateway Protocol (BGP) combined with Bidirectional Forwarding Detection (BFD) is typically used to improve network stability and reliability. BGP is used to exchange routing information between different autonomous systems, while BFD is used to quickly detect any link failures.

[0200] To achieve high availability, two physically independent cloud leased line links can be configured, one as the primary link and the other as a backup link. When the primary link fails, the system can quickly switch to the backup link to minimize network downtime. With the help of BGP, when one link fails, the user edge router can dynamically update its routing table to ensure that packets are transmitted through the other working link. This dynamic routing update helps maintain network stability and connectivity.

[0201] Maintaining the first and second BFD sessions means that health monitoring of these two links will not stop even after a path switch occurs. The BFD session, through its rapid fault detection mechanism, continuously verifies the connectivity of each link, providing real-time link status feedback.

[0202] In some embodiments, the cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively; the method further includes:

[0203] When the first gateway device detects that the state information of the first BFD session has changed from the execution state to the closed state, it reports the state change information of the first BFD session to the gateway control device.

[0204] If the first gateway device receives the first decision information carrying the closed state sent by the gateway control device, it generates the first closed state message information. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session has switched from the execution state to the closed state and the state information of the second BFD session has switched from the execution state to the closed state.

[0205] The first gateway device sends the first closed state message information to the user edge router through the access switch, so as to establish a third BFD session with the state information configured as executed between the user edge router and the first gateway device based on the first closed state message information, and to establish a fourth BFD session with the state information configured as executed between the user edge router and the second gateway device based on the first closed state message information.

[0206] When the first gateway device does not obtain the second closed state message information, it is determined that the communication between the first cloud private line link and at least one of the second cloud private line links is normal. The second closed state message information is generated when it is determined that the state information of the third BFD session changes from the execution state to the closed state, and the state information of the fourth BFD session changes from the execution state to the closed state.

[0207] The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are in normal communication between the first cloud leased line link and the second cloud leased line link, and to maintain the third and fourth BFD sessions.

[0208] Specifically, when the first gateway device receives the first decision information carrying the closed state from the gateway control device, it generates a first closed state message, indicating that both initially established BFD sessions are in the closed state. At this time, the first closed state message needs to be forwarded to the user edge router so that the user edge router and the first gateway device enter a renegotiation state to establish a new BFD session: so that the user edge router establishes a new BFD session with the first gateway device based on the received first closed state message, called the third BFD session, and its state information is configured as the execution state; at the same time, so that the user edge router establishes another new BFD session with the second gateway device, called the fourth BFD session, and its state information is also configured as the execution state.

[0209] Then, if the first gateway device does not obtain the second shutdown status message information, it can be determined that at least one of the first cloud leased line link and the second cloud leased line link is communicating normally. The second shutdown status message information is generated when the status information of both newly established BFD sessions (the third BFD session and the fourth BFD session) switches from the executing state to the shutdown state. Specifically, the second shutdown status message information is generated by the first gateway device based on the second decision information carrying the shutdown status issued by the gateway control device. The second decision information is generated by the gateway control device when it determines that the status information of the third BFD session switches from the executing state to the shutdown state, and the status information of the fourth BFD session switches from the executing state to the shutdown state.

[0210] Then, the user edge router is instructed to transmit data through at least one working cloud leased line link and maintain the newly established third and fourth BFD sessions. These steps are part of the network fault detection and recovery strategy, ensuring that the network can quickly restore normal communication in the event of a link failure, thus guaranteeing the continuity and stability of cloud leased line communication.

[0211] like Figure 5 As shown, when a link down is detected, due to the existence of two BFD sessions, there may be inconsistencies in their states. In this case, both the first gateway device 530 and the second gateway device 540 need to simultaneously report the state change information of the BFD sessions to the gateway control device 560 for adjudication. During the period before the gateway control device 560 makes its adjudication, the first gateway device 530, which is in a down state, will not send a shutdown (down) state message to prevent the BFD session of the user edge router 510 on the peer IDC side from being switched to a down state.

[0212] For example, when the first gateway device 530 detects that the state change information of the first BFD session has changed from the execution state to the closed state, it reports the state change information of the first BFD session to the gateway control device 560, which is connected to the first gateway device 630 and the second gateway device 640 respectively.

[0213] When the gateway control device 560 receives two down status messages, that is, when the gateway control device 560 receives the status change information of the first BFD session from the execution state to the closed state and the status change information of the second BFD session from the execution state to the closed state, it sends a decision message carrying the closed (down) status to the first gateway device 530. When the first gateway device 530 sends the closed (down) status message to the peer user edge router 510 through the access switch 520, the user edge router 510 and the first gateway device 530 enter the renegotiation state.

[0214] In some embodiments, the first gateway device sends a first shutdown state message to the user edge router via an access switch to establish a third BFD session with the state information configured as "executed" between the user edge router and the first gateway device based on the first shutdown state message, and to establish a fourth BFD session with the state information configured as "executed" between the user edge router and the second gateway device based on the shutdown state message, including:

[0215] The first gateway device sends the first closed state message information to the user edge router through the access switch, so that the user edge router can generate a new BFD message information based on the first closed state message information;

[0216] The first gateway device receives new BFD message information sent through the access switch;

[0217] After the first gateway device re-negotiates the session with the user edge router based on the new BFD message information, a third BFD session is established between the user edge router and the first gateway device. The state information of the third BFD session is configured to be in the execution state.

[0218] The negotiated BFD parameter information from the third BFD session is sent to the database so that the second gateway device can establish a fourth BFD session between the user edge router and the second gateway device based on the new BFD message information sent by the access switch and the negotiated BFD parameter information from the third BFD session obtained from the database. The status information of the fourth BFD session is configured as an execution state.

[0219] Please see Figure 5The renegotiation process is as follows: The first gateway device 530 sends the first closed state message information to the user edge router 510 through the access switch 520, so that the user edge router 510 generates new BFD message information based on the first closed state message information; the first gateway device 530 receives the new BFD message information sent through the access switch 520; after the first gateway device 530 renegoties the session with the user edge router 510 based on the new BFD message information, a third BFD session is established between the user edge router 510 and the first gateway device 530, and the status information of the third BFD session is configured as the execution state; the negotiated BFD parameter information in the third BFD session is sent to the database 550, so that the second gateway device 540 establishes a fourth BFD session between the user edge router 510 and the second gateway device 540 based on the new BFD message information sent by the access switch 520 and the negotiated BFD parameter information in the third BFD session obtained from the database 550, and the status information of the fourth BFD session is configured as the execution state.

[0220] In this embodiment, the first gateway device sends a first closed state message to the user edge router via the access switch, prompting the edge router to parse and generate a new BFD message based on the information. This step ensures timely communication of state changes and forms the basis for subsequent session reconstruction. The first gateway device receives the new BFD message generated by the user edge router forwarded by the access switch, and renegotiates with the edge router accordingly. Ultimately, a third BFD session is successfully established between the two, and its state information is set to "executive," indicating that the session is active and can perform link detection normally. To ensure multi-path redundancy and high availability, the negotiated parameter information from the third BFD session is stored in database 550. This process ensures that other gateway devices can quickly use these parameters to synchronously update their own BFD session states. The second gateway device 540 receives the new BFD message from the access switch and extracts the negotiated parameter information from the database 550. Using this data, the second gateway device can quickly establish a fourth BFD session with the user edge router 510 without repeated negotiation and similarly set its state to "executive." This design significantly improves the speed of fault detection and recovery in the network environment, and enhances the stability and reliability of the entire network architecture.

[0221] In some embodiments, after sending the first shutdown state message information to the user edge router through the access switch, the method further includes:

[0222] The first gateway device sends a deletion command to the database. The deletion command is used to instruct the deletion of the negotiated BFD parameter information in the first BFD session, so that the database responds to the deletion command and deletes the negotiated BFD parameter information in the first BFD session in the database, and the second gateway device responds to the deletion command according to the corresponding subscription message of the database and deletes the negotiated BFD parameter information in the first BFD session obtained by the second gateway device.

[0223] Please see Figure 5 After the first gateway device 530 sends the first shutdown state message to the user edge router 510 through the access switch 520, it also sends a deletion command to the database 550. This deletion command instructs the database 550 to delete the negotiated BFD parameter information from the first BFD session, causing the database 550 to delete this information in response. Similarly, the second gateway device 540, based on its corresponding subscription message to the database 550, deletes the negotiated BFD parameter information from the first BFD session it has acquired. This operation aims to clear out outdated session parameters, preventing network resource confusion and redundancy. Specifically, the database 550, in response to the deletion command, deletes the negotiated BFD parameter information from the first BFD session stored in its database, ensuring that the information stored in the database 550 remains up-to-date. After the second gateway device 540 receives the BFD parameter information deletion, it deletes its local BFD parameter information and local second BFD session. The entire network architecture then returns to the state of waiting for the first gateway device 530 to negotiate the session. Since the second gateway device 540 has pre-subscribed to relevant update messages from the database 550, it can immediately respond to this change notification after the database 550 performs a deletion operation, synchronously deleting the corresponding BFD parameter information from its cached first BFD session, thus ensuring consistent configuration across all nodes in the network. The second gateway device 540 not only synchronously deletes the old BFD parameter information from the database 550, but also terminates and clears the local second BFD session built based on these parameters, returning to the initial pending negotiation state. Through this mechanism, the entire network architecture can quickly adapt to changes in session state, efficiently establishing new BFD sessions to ensure link health monitoring, while simultaneously cleaning up old sessions and their parameters. This effectively avoids incorrect judgments and invalid resource consumption caused by outdated parameters, greatly improving the efficiency and accuracy of network maintenance. Furthermore, this real-time synchronization mechanism enhances the collaboration capabilities among multiple devices in the network, making the network architecture more flexible, robust, and easier to manage.

[0224] In some embodiments, after the first gateway device reports the closing status of the first BFD session to the gateway control device, the method further includes:

[0225] If the first gateway device does not receive the first decision information carrying the closed state from the gateway control device, the first gateway device is controlled to enter the waiting state within the negotiated detection period. The waiting state is used to indicate waiting for the execution state message information.

[0226] In the waiting state, if the first gateway device continuously receives a preset number of execution status messages, it will switch the status information of the first BFD session from the closed state to the execution state. The execution status messages originate from the user edge router.

[0227] Please see Figure 5 When the state information of the first BFD session of the first gateway device 530 switches to the down state, it may only be a brief and localized link jitter. In this case, the gateway control device 560 will not send the first decision information carrying the down state, indicating that it may determine that this state change is a temporary link instability phenomenon rather than a long-term link failure. In this situation, the first gateway device 530 will not immediately terminate the first BFD session, but will enter a waiting state (waiting for the up state message) to wait for more state information.

[0228] In the waiting state, the first gateway device 530 continuously monitors BFD packets from the user edge router 510 according to the negotiated monitoring cycle. If the first gateway device 530 does not receive a first decision message carrying a down state within the negotiated monitoring cycle, but continuously receives a preset number (e.g., 3) up state packets within the corresponding monitoring cycle, it indicates that the state of the second BFD session on the other side is normal. At this time, the state information of the first BFD session is directly restored to the up state, and monitoring continues. Based on the continuously received up state packets, the first gateway device 530 will immediately react, switching the state information of the first BFD session from the down state back to the up state, re-enabling the original BFD session, and resuming normal monitoring of the link state. This mechanism avoids frequent session restarts caused by temporary link problems, improves network stability, and reduces unnecessary network fluctuations and latency.

[0229] This application's embodiments, by introducing intelligent adjudication from the gateway control device, enable the network architecture to possess more refined link status judgment capabilities. This allows for flexible adjustments based on actual conditions, preventing overly sensitive response mechanisms from incurring additional network overhead and complexity. By setting a threshold for the number of consecutively received execution status messages, the accuracy of link status judgment is improved, reducing the false positive rate caused by brief link jitter. Rapidly restoring the first BFD session to the execution state ensures service continuity and high availability, avoiding service interruptions or performance degradation caused by short-term link issues. It also avoids frequent re-establishment of BFD sessions, saving network resources and processing time, making the entire network architecture operate more efficiently and stably.

[0230] In some embodiments, instructing the user edge router to communicate with the cloud leased gateway via at least one of the first and second cloud leased links that are in normal communication, and to maintain the first BFD session and the second BFD session, includes:

[0231] When the first gateway device detects fault information, it determines that the first cloud private line link communication is abnormal and that the second cloud private line link communication is normal.

[0232] Instruct the first gateway device and the second gateway device to perform a primary / backup identity switch, and maintain the first BFD session and the second BFD session;

[0233] Instruct the user edge router to communicate with the cloud leased line gateway through the second cloud leased line link where communication is normal.

[0234] In this process, based on step 740 which has determined that at least one of the first and second cloud leased line links is communicating normally, in step 750, while determining that the first cloud leased line is communicating abnormally based on the fault information of the first gateway device, it can further determine that the second cloud leased line is communicating normally based on step 740. Then, the first and second gateway devices are instructed to switch over their primary / backup roles. This switching mechanism ensures that even if the primary link fails, the backup link can immediately take over the traffic, guaranteeing uninterrupted data transmission. Maintaining the first and second BFD sessions is crucial in this process because it allows for continuous monitoring of the status of both links, enabling rapid identification of any new faults even after the primary / backup switchover.

[0235] Once the primary / backup switchover is complete, the user edge router will be instructed to transmit data via the currently functioning second cloud leased line link. This immediate path adjustment is based on real-time analysis and decision-making regarding network status, ensuring that communication between the user edge router and the cloud leased line gateway is not interrupted due to a link failure.

[0236] Even after a switchover, the first and second BFD sessions must be maintained to continuously monitor the communication status of the two links. Once the original faulty link restores normal communication through upgrade or repair operations, the link communication status can be reassessed using the two maintained BFD sessions, and a primary / backup switchover can be performed again if necessary to restore the optimal configuration.

[0237] In some embodiments, the first gateway device is identified as the primary gateway device, and the second gateway device is identified as the backup gateway device. Instructing the first gateway device and the second gateway device to perform a primary / backup identity switch and maintaining the first BFD session and the second BFD session includes:

[0238] Switch the identity of the first gateway device from the primary gateway device to the backup gateway device, and instruct the identity of the second gateway device to switch the identity of the backup gateway device to the primary gateway device;

[0239] The first gateway device maintains the first BFD session and instructs the second gateway device to maintain the second BFD session.

[0240] Please see Figure 6 By configuring the second gateway device 640 to handle the switching, when the cloud private line gateway performs a primary / backup switch, it is not necessary to send a BFD Admin Down message to the peer. For example... Figure 6 As shown, during primary / standby switchover, the BFD sessions remain unchanged. Specifically, when the first gateway device 630 detects fault information, during the primary / standby switchover process, only the routing protocol needs to perform the primary / standby switchover. The BFD sessions on the first gateway device 630 and the second gateway device 640 only need to remain unchanged, continuing to maintain two BFD sessions in the up state, thus simplifying the BFD processing logic during the primary / standby switchover process.

[0241] In certain implementation cases, the roles and functions of gateway devices are further refined and defined. In this configuration, the first gateway device is designated as the primary gateway device, while the second gateway device acts as the backup gateway device. This configuration is typically used to improve system reliability and stability, ensuring that even if the primary gateway device fails or malfunctions during network communication, the backup gateway device can quickly take over and maintain the continuous stability of the network connection.

[0242] For example, fault information may include, but is not limited to, physical fault information, logical fault information, power fault information, and connection fault information.

[0243] For example, physical fault information is usually related to the physical connections and hardware status of the device. For instance, the device will detect a line fault when the first gateway device experiences a broken line, a damaged port, or a loose plug. In addition, severe electromagnetic interference or physical damage to the device will also trigger corresponding physical fault information.

[0244] For example, logical fault information mainly relates to the device's software configuration and communication protocol. For instance, when the communication module of the first gateway device malfunctions, its address conflicts with other devices, its communication protocol is incompatible, or its system program malfunctions, the device will record the corresponding logical fault information. These types of faults are usually related to software configuration and firmware version and require software updates or configuration adjustments to resolve.

[0245] For example, power failure information primarily refers to problems related to the device's power supply. If the power cord of the first gateway device malfunctions, the power outlet is damaged, or the power adapter fails, the device will detect a power failure. Such failures typically prevent the device from receiving power and thus malfunction.

[0246] For example, connection failure information typically relates to the connection status of the first gateway device with other network devices. For instance, connection failure information is triggered when a device's network settings are incorrect, its signal is interfered with, or it is unable to establish a stable communication connection with other devices. Such failures may lead to data transmission interruptions or network instability.

[0247] When the first gateway device detects any of the aforementioned fault information, it indicates a potential malfunction or anomaly, preventing it from continuing normal network forwarding and detection. In this case, to ensure network communication stability and continuity, a failover mechanism is automatically triggered. The network architecture system, according to preset rules and procedures, automatically switches the first gateway device's identity from primary to backup, while simultaneously instructing the second gateway device to switch its identity from backup to primary. This failover process aims to ensure network communication continuity and stability, preventing network service interruption due to a single gateway device failure. After the identity switchover, the first gateway device maintains its first BFD session, even after its identity has changed to backup. This is to maintain network communication continuity and stability, preventing network connection anomalies caused by BFD session interruptions. Simultaneously, the second gateway device is instructed to maintain its second BFD session, ensuring the new primary gateway device can continue normal network forwarding and detection.

[0248] Please see Figure 6By setting up a backup gateway device (i.e., the second gateway device 640) as a proxy device, when the primary gateway device (i.e., the first gateway device 630) needs to perform a switchover, the system does not need to send a BFD AdminDown message to the peer to notify it to update its status. This design simplifies the signaling interaction and processing logic during the switchover process, improving the system's response speed and stability. During the switchover process, the routing protocol will be adjusted and updated accordingly to ensure that the new primary gateway device can correctly select and forward routes. However, the BFD sessions themselves do not need to be changed. That is, the BFD sessions on the first gateway device 630 and the second gateway device 640 will remain unchanged during the switchover process, continuing to maintain two BFD sessions in the up state. This design simplifies the BFD processing logic during the switchover process while ensuring the continuity and stability of network communication.

[0249] This application embodiment, by setting up primary and backup gateway devices and corresponding BFD session maintenance mechanisms, can simplify signaling interaction and processing logic during the primary / backup switchover process while ensuring network communication stability and continuity, thereby improving the overall performance and reliability of the system.

[0250] All of the above technical solutions can be combined in any way to form optional embodiments of this application, and will not be described in detail here.

[0251] In this embodiment, a first gateway device receives bidirectional forwarding detection (BFD) packets sent through an access switch, wherein the BFD packets originate from a user edge router. The first gateway device establishes a first BFD session with its state information configured as "executed" between the user edge router and the first gateway device based on the BFD packets. The first gateway device sends the negotiated BFD parameters from the first BFD session to a database, enabling a second gateway device to establish a second BFD session with its state information configured as "executed" between the user edge router and the second gateway device based on the BFD packets sent by the access switch and the negotiated BFD parameters from the first BFD session retrieved from the database. When the first gateway device fails to obtain the first BFD packet, the second gateway device... When a closed status message is sent, it is determined that at least one of the first cloud leased link and the second cloud leased link is communicating normally. The first cloud leased link is the cloud leased link between the user edge router and the first gateway device, and the second cloud leased link is the cloud leased link between the user edge router and the second gateway device. The first closed status message is generated when it is determined that the status information of the first BFD session has switched from the executing state to the closed state, and the status information of the second BFD session has switched from the executing state to the closed state. It instructs the user edge router to communicate with the cloud leased gateway through at least one of the first cloud leased link and the second cloud leased link that is communicating normally, and to maintain the first BFD session and the second BFD session. This application embodiment establishes two BFD sessions simultaneously between the user edge router and the first and second gateway devices on the cloud leased line gateway side, providing a dual BFD session mechanism. This ensures the stability of the BFD session during cloud leased line communication. This dual session mechanism ensures that even if one path fails or experiences jitter, the other path can still maintain BFD detection. The dual session mechanism enables seamless upgrade and failover capabilities, allowing seamless switching to the backup gateway device when the primary gateway device fails or requires upgrades or maintenance, without interrupting communication between the user edge router and the cloud leased line gateway, thus guaranteeing the continuity of the BFD session during cloud leased line communication. By establishing two independent BFD session paths, the probability of a single path jitter causing overall BFD session jitter is reduced. Furthermore, when the access switch does not receive the first closed status message from the first gateway device, it can determine that at least one cloud leased line link is communicating normally, thereby instructing the user edge router to communicate through the normally communicating link, improving the efficiency of fault handling.

[0252] This application proposes an innovative BFD session establishment and maintenance mechanism. By adding an additional BFD session with identical parameters to the cloud private line communication system and employing message replication and multi-point response methods, dual transmission and reception of BFD messages are achieved, thereby significantly enhancing the stability and reliability of the BFD session. When the cloud private line gateway undergoes software upgrades or encounters a fault, this additional maintained BFD session ensures that the BFD session status on the client side remains normal during the primary / backup switchover process, effectively preventing frequent session oscillations and the resulting routing convergence problems.

[0253] In this embodiment, the user edge router only needs to initiate one BFD session. The primary and backup gateway devices of the cloud private line gateway copy the received BFD message information through the forwarding device (access interaction device) so that it arrives at the primary and backup gateway devices at the same time. Then, each of them establishes an independent and corresponding BFD session with the user edge router based on the same parameters, thereby realizing the state mapping between one BFD session on the user edge router side and two primary and backup BFD sessions on the cloud private line gateway side.

[0254] During the negotiation and establishment of a BFD session, this embodiment employs an optimization strategy, whereby only the primary gateway device is responsible for the actual negotiation process to ensure successful session establishment and correct configuration. After session establishment, this embodiment introduces a database as the core element for parameter synchronization. Backup gateway devices do not need to repeat the negotiation process; instead, they directly read the negotiated BFD parameter information from the database, thereby quickly establishing their own BFD session.

[0255] Furthermore, this embodiment introduces a gateway control device as the core control node, responsible for detecting BFD status changes in the primary and backup gateway devices and making decision-making decisions. Only when both BFD sessions on the cloud private line gateway side are displayed as "down" will the gateway control device send decision information carrying the down status, ensuring the accuracy and consistency of network status by uniformly configuring all BFD sessions in the entire network architecture to the down state. The gateway control device also has the ability to manage access switches, controlling their multicast and distribution operations. Access switches can distribute BFD message information automatically or in response to controller commands to distribute replicated BFD message information. In addition, the gateway control device also distributes corresponding BFD configuration information to the first and second gateway devices respectively, ensuring that each device operates according to the correct configuration.

[0256] The BFD session architecture constructed using the above method ensures that when the primary cloud gateway device undergoes upgrades or experiences a failure, the backup gateway device's BFD session can still effectively maintain a normal session connection with the user's edge router. This provides ample time for system failover and effectively prevents instability and frequent oscillations in routing protocol neighbor relationships. Furthermore, the two independent BFD sessions cover two underlying network paths within the cloud, significantly reducing the risk of BFD session instability caused by a single path failure.

[0257] The proxy answering device in this embodiment is highly flexible in deployment; it can be deployed on a standby cloud dedicated line gateway or on any other server. This flexible design can adapt to different network environments and business needs.

[0258] In summary, this application provides an innovative BFD session construction and maintenance strategy. Through packet replication, collaborative operation of primary and backup gateway devices, the introduction of a database synchronization mechanism, and intelligent adjudication by the gateway control device, a single BFD session on the user edge router side can simultaneously establish effective BFD session connections with the primary and backup gateway devices of the cloud leased line gateway. This application is particularly suitable for cloud network access scenarios, providing users with highly reliable BFD capabilities. During primary / backup switching caused by software upgrades or failures of the cloud leased line gateway, the BFD session of the backup gateway device maintains a stable session state with the user side, ensuring that the user-side BFD session is unaffected, avoiding abnormal jitter, and ensuring that users are unaware of the BFD session down state, thus improving the user experience. Furthermore, this application embodiment reduces the latency sensitivity of the primary and backup gateway devices during data backup or restoration operations, providing more time for data backup or restoration. It also supports cross-availability zone disaster recovery capabilities for the cloud dedicated line gateway by deploying the primary and backup instances of dual-point probing in different availability zones. This prevents local link jitter within the cloud dedicated line gateway from causing BFD session jitter, thus improving the overall stability of the BFD session and significantly enhancing the reliability and service level of the entire system. Here, an availability zone refers to an IDC data center within the same region where power, network, and other resources are isolated. This primarily enables cross-availability zone disaster recovery on the cloud side. When an availability zone on the cloud dedicated line gateway side fails, a primary / backup switch can be performed to another availability zone to continue providing service.

[0259] To facilitate better implementation of the cloud private line communication method of this application embodiment, this application embodiment also provides an access switch. Please refer to... Figure 8 , Figure 8This is a schematic diagram of the access switch provided in an embodiment of this application. The access switch 800 is suitable for use in a cloud private line communication system. The cloud private line communication system includes a user edge router, an access switch, and a cloud private line gateway. The cloud private line gateway is configured with a first gateway device and a second gateway device. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The access switch 800 may include:

[0260] The first receiving unit 810 is used to receive bidirectional forwarding detection (BFD) message information, wherein the BFD message information originates from the user edge router.

[0261] The first sending unit 820 is configured to send BFD message information to the first gateway device and the second gateway device, so that the first gateway device establishes a first BFD session with the state information configured as execution state between the user edge router and the first gateway device based on the BFD message information, and so that the second gateway device establishes a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session.

[0262] The first determining unit 830 is used to determine that at least one of the first cloud private line links and the second cloud private line link is communicating normally when the access switch does not receive the first closed status message information fed back by the first gateway device. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed status message information is generated when it is determined that the status information of the first BFD session switches from the execution state to the closed state and the status information of the second BFD session switches from the execution state to the closed state.

[0263] The first processing unit 840 is used to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links in the first cloud leased link and the second cloud leased link, and to maintain the first BFD session and the second BFD session.

[0264] In some embodiments, the first processing unit 840 is specifically configured to: when the access switch receives fault information fed back by the first gateway device, determine that the first cloud leased line link communication is abnormal and determine that the second cloud leased line link communication is normal; instruct the first gateway device and the second gateway device to perform a primary / backup identity switch and maintain the first BFD session and the second BFD session; instruct the user edge router to communicate with the cloud leased line gateway through the second cloud leased line link with normal communication.

[0265] In some embodiments, the first BFD session is established between the user edge router and the first gateway device after the first gateway device negotiates the session with the user edge router based on the BFD message information. The negotiated BFD parameter information in the first BFD session is generated by the first gateway device after negotiating the session with the user edge router based on the BFD message information.

[0266] In some embodiments, the cloud private line communication system further includes a database, which is connected to both the first gateway device and the second gateway device. The negotiated BFD parameter information in the first BFD session obtained by the second gateway device is retrieved from the database, wherein the negotiated BFD parameter information in the first BFD session in the database is sent by the first gateway device. The second BFD session is established between the user edge router and the second gateway device based on the BFD message information and the negotiated BFD parameter information in the first BFD session, obtained by the second gateway device from the database according to the subscription message corresponding to the database.

[0267] In some embodiments, the negotiated BFD parameter information obtained by the second gateway device in the first BFD session is obtained by the second gateway device from the first gateway device; the second BFD session is established between the user edge router and the second gateway device based on the BFD message information and the negotiated BFD parameter information in the first BFD session obtained by the second gateway device from the first gateway device.

[0268] In some embodiments, the negotiated BFD parameter information in the first BFD session obtained by the second gateway device is obtained by the second gateway device from the first gateway device; the second BFD session is established between the user edge router and the second gateway device based on the negotiated BFD parameter information in the first BFD session obtained by the second gateway device from the second gateway device, and the BFD message information and the negotiated BFD parameter information in the first BFD session. The state information of the second BFD session is configured as an execution state.

[0269] In some embodiments, the first sending unit 820 is further configured to send the first shutdown status message to the user edge router when the access switch receives the first shutdown status message information fed back by the first gateway device, so as to establish a third BFD session with the status information configured as execution state between the user edge router and the first gateway device based on the first shutdown status message information, and to establish a fourth BFD session with the status information configured as execution state between the user edge router and the second gateway device based on the first shutdown status message information;

[0270] The first determining unit 830 is further configured to determine that at least one of the cloud private line links of the first cloud private line link and the second cloud private line link is communicating normally when the access switch does not receive the second closed status message information fed back by the first gateway device. The second closed status message information is generated when the status information of the third BFD session is determined to switch from the execution state to the closed state and the status information of the fourth BFD session is determined to switch from the execution state to the closed state.

[0271] The first processing unit 840 is also configured to instruct the user edge router to communicate with the cloud leased gateway through at least one cloud leased link in the first cloud leased link and the second cloud leased link, and to maintain the third BFD session and the fourth BFD session.

[0272] In some embodiments, the cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively;

[0273] The first closed state message information is generated by the first gateway device based on the first decision information carrying the closed state issued by the gateway control device. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session has switched from the execution state to the closed state, and the state information of the second BFD session has switched from the execution state to the closed state.

[0274] The second closed status message is generated by the first gateway device based on the second decision information carrying the closed status issued by the gateway control device. The second decision information is generated by the gateway control device when it determines that the status information of the third BFD session has switched from the execution state to the closed state, and the status information of the fourth BFD session has switched from the execution state to the closed state.

[0275] In some embodiments, the first sending unit 820 is further configured to send the first shutdown status message information to the user edge router when it receives the first shutdown status message information fed back by the first gateway device, so that the user edge router generates new BFD message information according to the first shutdown status message information;

[0276] The first receiving unit 810 is also used to receive new BFD message information;

[0277] The first sending unit 820 is further configured to send new BFD message information to the first gateway device and the second gateway device, so that after the first gateway device re-negotiates the session with the user edge router based on the new BFD message information, a third BFD session with the state information configured as execution is established between the user edge router and the first gateway device, and to enable the second gateway device to establish a fourth BFD session with the state information configured as execution is established between the user edge router and the second gateway device based on the new BFD message information and the BFD parameter information negotiated in the third BFD session.

[0278] In some embodiments, the first sending unit 820 is specifically used to: copy the BFD message information and send the copied BFD message information to the first gateway device and the second gateway device according to a preset sending method, wherein the preset sending method includes one of simultaneous sending, separate sending and sequential sending.

[0279] This application also provides a gateway device. Please refer to... Figure 9 , Figure 9 This is a schematic diagram of the gateway device provided in an embodiment of this application. The gateway device 900 is applicable as a first gateway device in a cloud private line communication system. The cloud private line communication system includes a user edge router, an access switch, a cloud private line gateway, and a database. A first gateway device and a second gateway device are configured on the cloud private line gateway. The user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch. The database is connected to both the first gateway device and the second gateway device. The gateway device 900 is the first gateway device, and it may include:

[0280] The second receiving unit 910 is used to receive bidirectional forwarding detection (BFD) message information sent through the access switch, wherein the BFD message information originates from the user edge router.

[0281] The first establishment unit 920 is used to establish a first BFD session between the user edge router and the first gateway device based on BFD message information, wherein the state information is configured to be in the execution state.

[0282] The second sending unit 930 is used to send the negotiated BFD parameter information in the first BFD session to the database, so that the second gateway device can establish a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information sent by the access switch and the negotiated BFD parameter information in the first BFD session obtained from the database.

[0283] The second determining unit 940 is used to determine that at least one of the first cloud private line links and the second cloud private line link is communicating normally when the first gateway device does not obtain the first closed state message information. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session switches from the execution state to the closed state and the state information of the second BFD session switches from the execution state to the closed state.

[0284] The second processing unit 950 is used to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links in the first cloud leased link and the second cloud leased link, and to maintain the first BFD session and the second BFD session.

[0285] In some embodiments, the second processing unit 950 is specifically configured to: when the first gateway device detects fault information, determine that the first cloud leased line link communication is abnormal, and determine that the second cloud leased line link communication is normal; instruct the first gateway device and the second gateway device to perform a primary / backup identity switch, and maintain the first BFD session and the second BFD session; instruct the user edge router to communicate with the cloud leased line gateway through the second cloud leased line link with normal communication.

[0286] In some embodiments, the first gateway device is identified as a primary gateway device and the second gateway device is identified as a backup gateway device. The second processing unit 950 is further configured to: switch the identity of the first gateway device from primary gateway device to backup gateway device, and instruct the identity of the second gateway device to be switched from backup gateway device to primary gateway device; the first gateway device maintains a first BFD session, and instructs the second gateway device to maintain a second BFD session.

[0287] In some embodiments, the first establishment unit 920 is specifically used to establish a first BFD session between the user edge router and the first gateway device after negotiating a session with the user edge router based on BFD message information; generate negotiated BFD parameter information in the first BFD session; and configure the status information of the first BFD session to an execution state.

[0288] In some embodiments, when the second gateway device establishes a second BFD session, the status information of the second BFD session is configured as an execution state.

[0289] In some embodiments, the cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively; the gateway device 900 further includes:

[0290] The first reporting unit is used to report the status change information of the first BFD session to the gateway control device when it detects that the status information of the first BFD session has switched from the execution state to the closed state.

[0291] The first generation unit is configured to generate a first closed state message if it receives a first decision information carrying a closed state from the gateway control device. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session has switched from the execution state to the closed state and the state information of the second BFD session has switched from the execution state to the closed state.

[0292] The second sending unit 930 is further configured to send the first closed state message information to the user edge router through the access switch, so as to establish a third BFD session with the state information configured as executed between the user edge router and the first gateway device based on the first closed state message information, and to establish a fourth BFD session with the state information configured as executed between the user edge router and the second gateway device based on the first closed state message information.

[0293] The second determining unit 940 is further configured to determine that at least one of the cloud private line links of the first cloud private line link and the second cloud private line link is communicating normally when the first gateway device does not obtain the second closed state message information. The second closed state message information is generated when the state information of the third BFD session is determined to switch from the execution state to the closed state and the state information of the fourth BFD session is determined to switch from the execution state to the closed state.

[0294] The second processing unit 950 is also configured to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links in the first cloud leased link and the second cloud leased link, and to maintain the third BFD session and the fourth BFD session.

[0295] In some embodiments, the second sending unit 930 is further configured to send the first closed state message information to the user edge router through the access switch, so that the user edge router generates new BFD message information based on the first closed state message information;

[0296] The second receiving unit 910 is also used to receive new BFD message information sent through the access switch;

[0297] The first establishment unit 920 is also used to establish a third BFD session between the user edge router and the first gateway device after renegotiation of the session with the user edge router based on the new BFD message information. The status information of the third BFD session is configured as an execution state.

[0298] The second sending unit 930 is further configured to send the negotiated BFD parameter information in the third BFD session to the database, so that the second gateway device can establish a fourth BFD session between the user edge router and the second gateway device based on the new BFD message information sent by the access switch and the negotiated BFD parameter information in the third BFD session obtained from the database. The status information of the fourth BFD session is configured as an execution state.

[0299] In some embodiments, the second sending unit 930 is further configured to: send a deletion instruction to the database, the deletion instruction being used to instruct the deletion of negotiated BFD parameter information in the first BFD session, so that the database responds to the deletion instruction by deleting the negotiated BFD parameter information in the first BFD session in the database, and to cause the second gateway device to respond to the deletion instruction according to the subscription message corresponding to the database by deleting the negotiated BFD parameter information obtained in the first BFD session in the second gateway device.

[0300] In some embodiments, the second processing unit 950 is further configured to: after the first reporting unit reports the closed status of the first BFD session to the gateway control device, if the second receiving unit 910 does not receive the first decision information carrying the closed status issued by the gateway control device, control the first gateway device to enter a waiting state within the negotiated detection period, the waiting state being used to indicate waiting for execution status message information; in the waiting state, if the second receiving unit 910 continuously receives a preset number of execution status message information, switch the status information of the first BFD session from the closed state to the execution state, the execution status message information originating from the user edge router.

[0301] In some embodiments, the first gateway device is identified as a primary gateway device, and the second gateway device is identified as a backup gateway device. The gateway device further includes a second processing unit, configured to: when fault information is detected, switch the identity of the first gateway device from primary gateway device to backup gateway device, and instruct the identity of the second gateway device to switch from backup gateway device to primary gateway device; control the first gateway device to maintain a first BFD session, and instruct the second gateway device to maintain a second BFD session.

[0302] It should be noted that the functions of each unit in the access switch 800 and gateway device 900 in this application embodiment can be referred to the specific implementation of any embodiment in the above method embodiments, and will not be repeated here.

[0303] Each unit in the access switch 800 and gateway device 900 can be implemented entirely or partially through software, hardware, or a combination thereof. Each unit can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each unit.

[0304] In some embodiments, this application also provides a computer-readable storage medium for storing a computer program. This computer-readable storage medium can be applied to a computer device, and the computer program causes the computer device to execute the corresponding processes in the methods described above in the embodiments of this application; for brevity, further details are omitted here.

[0305] In some embodiments, this application also provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the corresponding processes in the methods described above in the embodiments of this application. For brevity, these details will not be elaborated further here.

[0306] This application also provides a computer program that includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the corresponding processes in the methods described above in the embodiments of this application. For brevity, these details will not be elaborated further here.

[0307] It should be understood that the processor in the embodiments of this application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0308] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0309] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0310] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0311] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0312] In this application embodiment, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0313] The unit described as a separate component may or may not be physically separate. The component shown as a unit may or may not be a physical unit; that is, it may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0314] In addition, the functional units in the embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0315] If this function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer or a server) to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0316] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cloud private line communication method, applicable to a cloud private line communication system, wherein the cloud private line communication system includes a user edge router, an access switch, and a cloud private line gateway, wherein a first gateway device and a second gateway device are configured in the cloud private line gateway, and the user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch, characterized in that, The method includes: The access switch receives bidirectional forwarding detection (BFD) packets, wherein the BFD packets originate from the user edge router. The access switch sends the BFD message information to the first gateway device and the second gateway device, so that the first gateway device establishes a first BFD session with the state information configured as execution between the user edge router and the first gateway device based on the BFD message information, and so that the second gateway device establishes a second BFD session with the state information configured as execution between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session; When the access switch does not receive the first shutdown status message information fed back by the first gateway device, it determines that at least one of the first cloud private line link and the second cloud private line link is communicating normally. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first shutdown status message information is generated when it is determined that the status information of the first BFD session switches from the execution state to the shutdown state, and the status information of the second BFD session switches from the execution state to the shutdown state. The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and to maintain the first BFD session and the second BFD session.

2. The method as described in claim 1, characterized in that, The instruction to the user edge router to communicate with the cloud leased gateway via at least one of the first and second cloud leased links that are communicating normally, and to maintain the first BFD session and the second BFD session, includes: When the access switch receives the fault information fed back by the first gateway device, it determines that the first cloud private line link communication is abnormal and that the second cloud private line link communication is normal. Instruct the first gateway device and the second gateway device to perform a primary / backup identity switch, and maintain the first BFD session and the second BFD session; The user edge router is instructed to communicate with the cloud leased line gateway through the second cloud leased line link, which is in good communication condition.

3. The method as described in claim 1, characterized in that, The first BFD session is established between the user edge router and the first gateway device after the first gateway device negotiates the session with the user edge router based on the BFD message information. The negotiated BFD parameter information in the first BFD session is generated by the first gateway device after negotiating the session with the user edge router based on the BFD message information.

4. The method as described in claim 3, characterized in that, The cloud private line communication system also includes a database, which is connected to the first gateway device and the second gateway device respectively. The negotiated BFD parameter information in the first BFD session obtained by the second gateway device is obtained by the second gateway device from the database, wherein the negotiated BFD parameter information in the first BFD session in the database is sent by the first gateway device; The second BFD session is established between the user edge router and the second gateway device based on the BFD message information and the negotiated BFD parameter information in the first BFD session obtained from the database according to the subscription message corresponding to the database.

5. The method as described in claim 3, characterized in that, The negotiated BFD parameter information obtained by the second gateway device in the first BFD session is obtained by the second gateway device from the first gateway device; The second BFD session is established between the user edge router and the second gateway device based on the BFD message information obtained by the second gateway device from the negotiated BFD parameter information in the first BFD session and the negotiated BFD parameter information in the first BFD session.

6. The method as described in claim 1, characterized in that, The method further includes: When the access switch receives the first shutdown status message information fed back by the first gateway device, it sends the first shutdown status message information to the user edge router to establish a third BFD session with the status information configured as execution state between the user edge router and the first gateway device based on the first shutdown status message information, and to establish a fourth BFD session with the status information configured as execution state between the user edge router and the second gateway device based on the first shutdown status message information. When the access switch does not receive the second shutdown status message information fed back by the first gateway device, it determines that the communication between the first cloud private line link and at least one of the second cloud private line links is normal. The second shutdown status message information is generated when it is determined that the status information of the third BFD session switches from the execution state to the shutdown state, and the status information of the fourth BFD session switches from the execution state to the shutdown state. The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and to maintain the third BFD session and the fourth BFD session.

7. The method as described in claim 6, characterized in that, The cloud private line communication system also includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively; The first closed state message information is generated by the first gateway device based on the first decision information carrying the closed state issued by the gateway control device. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state. The second closed status message information is generated by the first gateway device based on the second decision information carrying the closed status issued by the gateway control device. The second decision information is generated by the gateway control device when it determines that the status information of the third BFD session has switched from the execution state to the closed state, and the status information of the fourth BFD session has switched from the execution state to the closed state.

8. The method as described in claim 6, characterized in that, When the access switch receives the first shutdown status message information fed back by the first gateway device, it sends the first shutdown status message information to the user edge router to establish a third BFD session with the status information configured as "executed" between the user edge router and the first gateway device based on the first shutdown status message information, and to establish a fourth BFD session with the status information configured as "executed" between the user edge router and the second gateway device based on the first shutdown status message information, including: When the access switch receives the first shutdown status message information fed back by the first gateway device, it sends the first shutdown status message information to the user edge router, so that the user edge router generates new BFD message information based on the first shutdown status message information; The access switch receives the new BFD message information; The access switch sends the new BFD message information to the first gateway device and the second gateway device, so that the first gateway device, based on the new BFD message information, re-negotiates the session with the user edge router and establishes a third BFD session between the user edge router and the first gateway device with the state information configured as "executed". The second gateway device, based on the new BFD message information and the BFD parameter information negotiated in the third BFD session, establishes a fourth BFD session between the user edge router and the second gateway device with the state information configured as "executed".

9. The method as described in claim 1, characterized in that, The access switch sends the BFD message information to the first gateway device and the second gateway device, including: The access switch copies the BFD message information and sends the copied BFD message information to the first gateway device and the second gateway device according to a preset sending method, which includes one of simultaneous sending, separate sending, and sequential sending.

10. A cloud private line communication method, applicable to a cloud private line communication system, wherein the cloud private line communication system includes a user edge router, an access switch, a cloud private line gateway, and a database; the cloud private line gateway is configured with a first gateway device and a second gateway device; the user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch; and the database is connected to the first gateway device and the second gateway device respectively, characterized in that... The method includes: The first gateway device receives bidirectional forwarding detection (BFD) message information sent through the access switch, wherein the BFD message information originates from the user edge router; The first gateway device establishes a first BFD session with the state information configured as execution state between the user edge router and the first gateway device based on the BFD message information; The first gateway device sends the negotiated BFD parameter information from the first BFD session to the database, so that the second gateway device establishes a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information sent by the access switch and the negotiated BFD parameter information from the first BFD session obtained from the database. When the first gateway device does not obtain the first closed state message information, it is determined that at least one of the first cloud private line link and the second cloud private line link is communicating normally. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state. The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and to maintain the first BFD session and the second BFD session.

11. The method as described in claim 10, characterized in that, The instruction to the user edge router to communicate with the cloud leased gateway via at least one of the first and second cloud leased links that are communicating normally, and to maintain the first BFD session and the second BFD session, includes: When the first gateway device detects fault information, it determines that the first cloud private line link communication is abnormal and that the second cloud private line link communication is normal. Instruct the first gateway device and the second gateway device to perform a primary / backup identity switch, and maintain the first BFD session and the second BFD session; The user edge router is instructed to communicate with the cloud leased line gateway through the second cloud leased line link, which is in good communication condition.

12. The method as described in claim 11, characterized in that, The first gateway device is identified as the primary gateway device, and the second gateway device is identified as the backup gateway device. The step of instructing the first gateway device and the second gateway device to perform a primary / backup identity switch and maintaining the first BFD session and the second BFD session includes: The identity of the first gateway device is switched from the primary gateway device to the backup gateway device, and the identity of the second gateway device is switched from the backup gateway device to the primary gateway device. The first gateway device maintains the first BFD session and instructs the second gateway device to maintain the second BFD session.

13. The method as described in claim 10, characterized in that, The first gateway device establishes a first BFD session with its state information configured as "executed" between the user edge router and the first gateway device based on the BFD message information, including: After the first gateway device negotiates a session with the user edge router based on the BFD message information, it establishes a first BFD session between the user edge router and the first gateway device. Generate the negotiated BFD parameter information in the first BFD session; Configure the status information of the first BFD session to be in execution state.

14. The method as described in claim 10, characterized in that, The cloud private line communication system further includes a gateway control device, which is connected to the first gateway device and the second gateway device respectively; the method further includes: When the first gateway device detects that the state change information of the first BFD session is that the state information of the first BFD session has switched from the execution state to the closed state, it reports the state change information of the first BFD session to the gateway control device. If the first gateway device receives a first decision information carrying a closed state from the gateway control device, then the first closed state message information is generated. The first decision information is generated by the gateway control device when it determines that the state information of the first BFD session has switched from the execution state to the closed state, and the state information of the second BFD session has switched from the execution state to the closed state. The first gateway device sends the first shutdown state message information to the user edge router through the access switch, so as to establish a third BFD session with the state information configured as execution state between the user edge router and the first gateway device based on the first shutdown state message information, and to establish a fourth BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the first shutdown state message information. When the first gateway device does not obtain the second closed state message information, it is determined that the communication between the first cloud private line link and at least one of the second cloud private line links is normal. The second closed state message information is generated when it is determined that the state information of the third BFD session switches from the execution state to the closed state, and the state information of the fourth BFD session switches from the execution state to the closed state. The user edge router is instructed to communicate with the cloud leased line gateway through at least one of the cloud leased line links that are communicating normally between the first cloud leased line link and the second cloud leased line link, and to maintain the third BFD session and the fourth BFD session.

15. The method as described in claim 14, characterized in that, After sending the first shutdown status message information to the user edge router through the access switch, the method further includes: The first gateway device sends a deletion command to the database. The deletion command is used to instruct the deletion of the negotiated BFD parameter information in the first BFD session, so that the database responds to the deletion command by deleting the negotiated BFD parameter information in the first BFD session in the database, and the second gateway device responds to the deletion command according to the subscription message corresponding to the database by deleting the negotiated BFD parameter information in the first BFD session obtained by the second gateway device.

16. The method as described in claim 14, characterized in that, After the first gateway device reports the closing status of the first BFD session to the gateway control device, the method further includes: If the first gateway device does not receive the first decision information carrying the closed state issued by the gateway control device, the first gateway device is controlled to enter the waiting state within the negotiated detection period. The waiting state is used to indicate waiting for the execution state message information. In the waiting state, if the first gateway device continuously receives a preset number of execution status messages, it switches the status information of the first BFD session from the closed state to the execution state, and the execution status messages originate from the user edge router.

17. An access switch, applicable to an access switch in a cloud private line communication system, the cloud private line communication system comprising a user edge router, the access switch, and a cloud private line gateway, wherein the cloud private line gateway is configured with a first gateway device and a second gateway device, and the user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch, characterized in that, The access switch includes: The first receiving unit is used to receive bidirectional forwarding detection (BFD) message information, wherein the BFD message information originates from the user edge router; The first sending unit is configured to send the BFD message information to the first gateway device and the second gateway device, so that the first gateway device establishes a first BFD session with the state information configured as execution state between the user edge router and the first gateway device based on the BFD message information, and to enable the second gateway device to establish a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information and the BFD parameter information negotiated in the first BFD session; The first determining unit is configured to determine that at least one of the first cloud private line links and the second cloud private line link is communicating normally when the access switch does not receive the first closed status message information fed back by the first gateway device. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed status message information is generated when it is determined that the status information of the first BFD session switches from the execution state to the closed state, and the status information of the second BFD session switches from the execution state to the closed state. The first processing unit is configured to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links that are communicating normally between the first cloud leased link and the second cloud leased link, and to maintain the first BFD session and the second BFD session.

18. A gateway device, applicable to a first gateway device in a cloud private line communication system, the cloud private line communication system comprising a user edge router, an access switch, a cloud private line gateway, and a database, wherein a first gateway device and a second gateway device are configured in the cloud private line gateway, the user edge router is connected to the first gateway device and the second gateway device of the cloud private line gateway respectively through the access switch, and the database is connected to the first gateway device and the second gateway device respectively, characterized in that, The gateway device includes: The second receiving unit is used to receive bidirectional forwarding detection (BFD) message information sent through the access switch, wherein the BFD message information originates from the user edge router. The first establishment unit is used to establish a first BFD session with the state information configured as an execution state between the user edge router and the first gateway device based on the BFD message information. The second sending unit is used to send the negotiated BFD parameter information in the first BFD session to the database, so that the second gateway device establishes a second BFD session with the state information configured as execution state between the user edge router and the second gateway device based on the BFD message information sent by the access switch and the negotiated BFD parameter information in the first BFD session obtained from the database. The second determining unit is configured to determine that at least one of the first cloud private line links and the second cloud private line link is communicating normally when the first gateway device does not obtain the first closed state message information. The first cloud private line link is the cloud private line link between the user edge router and the first gateway device, and the second cloud private line link is the cloud private line link between the user edge router and the second gateway device. The first closed state message information is generated when it is determined that the state information of the first BFD session switches from the execution state to the closed state, and the state information of the second BFD session switches from the execution state to the closed state. The second processing unit is configured to instruct the user edge router to communicate with the cloud leased gateway through at least one of the cloud leased links that are communicating normally between the first cloud leased link and the second cloud leased link, and to maintain the first BFD session and the second BFD session.

19. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program adapted for loading by a processor to execute the cloud private line communication method as described in any one of claims 1-16.

20. A computer program product comprising computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the cloud private line communication method according to any one of claims 1-16.

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