WO2024114329A1 - Link discovery method, apparatus, and system - Google Patents

Abstract

The present invention relates to the technical field of networks, and provides a link discovery method, apparatus, and system. The method comprises: a controller acquires first discovery information and second discovery information, the first discovery information being discovery information of a first link acquired by a first network device on the basis of a clock protocol packet, the second discovery information being discovery information of the first link acquired by a second network device on the basis of the clock protocol packet, the first network device being in a first network domain, the second network device being in a second network domain, the network type of the first network domain being different from that of the second network domain, and the first link being a cross-domain link between a first port of the first network device and a second port of the second network device; and the controller determines the first link on the basis of the first discovery information and the second discovery information. According to the link discovery solution provided in the present application, a cross-domain link can be discovered, and the link discovery solution has a wide range of application scenarios and strong universality.

Description

Link discovery method, device and system

This application claims the priority of a Chinese patent application filed on November 29, 2022, with application number 202211511422.6, and application name “A method and device for information processing”, as well as the priority of a Chinese patent application filed on January 18, 2023, with application number 202310086087.8, and application name “Link discovery method, device and system”. The entire contents of these two patent applications are incorporated into this application by reference.

Technical Field

The present application relates to the field of network technology, and in particular to a link discovery method, device and system.

Background technique

Cross-domain links refer to communication links between different network domains. In the process of network maintenance, fault handling, network cutover, etc., it is often necessary to obtain the network topology of the communication network, which requires the discovery of cross-domain links in the communication network.

Currently, network devices obtain discovery information of cross-domain links through the link layer discovery protocol (LLDP) and report the discovery information of cross-domain links to the controller, so that the controller can discover the cross-domain links.

However, discovering cross-domain links through LLDP requires that network devices in different network domains all support LLDP, which limits the application scenarios of discovering cross-domain links through LLDP, and the universality of this cross-domain link discovery solution is poor.

Summary of the invention

The present application provides a link discovery method, device and system. The technical solution of the present application is as follows.

In a first aspect, a link discovery method is provided, the method comprising: a controller obtains first discovery information and second discovery information, the first discovery information is discovery information of a first link obtained by a first network device based on a clock protocol message, the second discovery information is discovery information of the first link obtained by a second network device based on the clock protocol message, the first network device is in a first network domain, the second network device is in a second network domain, the network type of the first network domain is different from the network type of the second network domain, and the first link is a cross-domain link between a first port of the first network device and a second port of the second network device; the controller determines the first link based on the first discovery information and the second discovery information.

At present, cross-domain links are usually discovered through LLDP, which requires that network devices in different network domains support LLDP, resulting in limited application scenarios of the solution and poor universality. For example, in the scenario where LLDP is used to discover cross-domain links between the optical network domain and the Internet Protocol (IP) network domain, the single board of the optical network device (or wavelength division device) needs to support LLDP, but currently only a few single boards of wavelength division devices support LLDP, which results in that in most scenarios, LLDP cannot be used to discover cross-domain links between the optical network domain and the IP network domain. The present application discovers cross-domain links between different network domains based on clock protocol messages. For example, the cross-domain link between the optical network domain and the IP network domain is discovered based on the clock protocol message. Since most network devices support the clock protocol, the cross-domain link discovery solution of the present application can be applied to most network scenarios. The cross-domain link discovery solution of the present application has a wide range of application scenarios and strong universality.

Optionally, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port, and the controller determines the first link according to the first discovery information and the second discovery information, including: the controller determines the first port of the first network device according to the indication information of the first port; the controller determines the second port of the second network device according to the indication information of the second port; the controller determines that the first port corresponds to the second port according to the correspondence. The controller determines that the first port corresponds to the second port, that is, the controller discovers the first link between the first port and the second port.

Optionally, the first discovery information also includes indication information of the first network device, the second discovery information also includes indication information of the second network device, and the controller determines the first link according to the first discovery information and the second discovery information, and further includes: the controller determines the first network device according to the indication information of the first network device; the controller determines the second network device according to the indication information of the second network device. Since the first discovery information includes the indication information of the first network device and the indication information of the first port, the controller can determine that the first port belongs to the first network device according to the first discovery information; since the second discovery information includes the indication information of the second network device and the indication information of the second port, the controller can determine that the second port belongs to the second network device according to the second discovery information; thereby facilitating the controller to determine the first link between the first port and the second port.

Optionally, before the controller obtains the first discovery information and the second discovery information, the method further includes: the controller sends a target policy to the first network device and the second network device, the target policy being used to instruct the first network device and the second network device to discover a cross-domain link between the first network domain and the second network domain based on the first clock protocol, wherein the clock protocol message is a message based on the first clock protocol. The target policy is a link discovery policy based on the first clock protocol.

The technical solution provided by the present application is that the controller sends a target policy to the first network device and the second network device, so that the first network device can obtain the first discovery information based on the clock protocol message, and the second network device can obtain the second discovery information based on the clock protocol message, so that the controller determines the first link according to the first discovery information and the second discovery information.

Optionally, before the controller sends the target policy to the first network device and the second network device, the method also includes: the controller obtains first capability information and second capability information, the first capability information is used to indicate that the first port supports the first clock protocol (that is, the first port supports the link discovery capability based on the first clock protocol), and the second capability information is used to indicate that the second port supports the first clock protocol (that is, the second port supports the link discovery capability based on the first clock protocol); the controller determines the target policy based on the first capability information and the second capability information.

The technical solution provided by the present application is that since the target policy is determined by the controller based on the first capability information and the second capability information, the target policy can adapt to the link discovery capability of the first port of the first network device and the link discovery capability of the second port of the second network device, thereby facilitating the first network device and the second network device to execute the target policy to obtain link discovery information.

Optionally, the controller is a cross-domain controller, and the controller obtains first discovery information and second discovery information, including: the controller receives first discovery information sent by a first controller, and the first controller is a controller of a first network domain; the controller receives second discovery information sent by a second controller, and the second controller is a controller of a second network domain.

Optionally, the cross-domain controller, the first controller, and the second controller are three different controllers. For example, the first controller is in the first network domain, the second controller is in the second network domain, the cross-domain controller is outside the first network domain, and the cross-domain controller is outside the second network domain.

Optionally, at least two of the cross-domain controller, the first controller, and the second controller are one controller. For example, the cross-domain controller is one controller, and the first controller and the second controller are the same controller; or, the cross-domain controller, the first controller, and the second controller are one controller.

Optionally, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain. For example, the first network domain is an IP network domain, and the second network domain is an optical network domain. For example, the optical network domain is an optical transmission network (OTN).

Optionally, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain. For example, the first network domain is a wireless network domain, and the second network domain is a wired network domain.

In a second aspect, a link discovery method is provided, the method comprising: a controller acquires first capability information and second capability information, the first capability information being used to indicate a link discovery capability supported by a first port of a first network device, the second capability information being used to indicate a link discovery capability supported by a second port of a second network device, the first network device being in a first network domain, the second network device being in a second network domain, and a network type of the first network domain being different from a network type of the second network domain; the controller sends a target policy to the first network device and the second network device, the target policy being used to instruct the first network device and the second network device to discover a cross-domain link between the first network domain and the second network domain based on the target policy, the target policy being determined based on the first capability information and the second capability information.

At present, the staff determines the discovery strategy of the cross-domain link according to the network situation, which requires the staff to be familiar with the network situation and has high requirements for the staff. The technical solution provided by the present application is that the controller determines the target strategy according to the first capability information and the second capability information, that is, the controller determines the discovery strategy of the cross-domain link according to the link discovery capability supported by the network port. The process of determining the discovery strategy of the cross-domain link does not require manual participation, and the requirements for the staff are relatively low.

Optionally, the target strategy includes at least one of the following: a link discovery strategy based on a first clock protocol; a link discovery strategy based on a first discovery protocol; a link discovery strategy based on port traffic statistics; a link discovery strategy based on port alarms. For example, the first discovery protocol is LLDP or other link discovery protocols. The first clock protocol is the Institute of Electrical and Electronics Engineers (IEEE) 1588 protocol, the International Telecommunication Union Telecommunication Standardization Sector (ITU-T for ITU Telecommunication Standardization Sector, ITU-T) G.8275.1 protocol or other clock protocols. For example, the first clock protocol is IEEE 1588 version 2 (version 2, V2). The IEEE 1588 protocol is also called the 1588 protocol or the precision time protocol (PTP). The full name of the 1588 protocol is: Precision Clock Synchronization Protocol Standard for Network Measurement and Control Systems. The ITU-TG.8275.1 protocol is also called the G.8275.1 protocol. The ITU-TG.8275.1 protocol defines a telecommunication-grade precision time protocol telecom profile for phase/time synchronization with full timing support from the network.

Optionally, before the controller sends the target policy to the first network device and the second network device, the method further includes: the controller according to The first capability information and the second capability information determine the target policy.

The technical solution provided by the present application is that the controller determines the target strategy based on the first capability information and the second capability information, that is, the controller determines the cross-domain link discovery strategy based on the link discovery capability supported by the network port. Therefore, the process of determining the cross-domain link discovery strategy does not require human participation and has low requirements for staff.

Optionally, the controller determines the target policy according to the first capability information and the second capability information, including:

When the first capability information is used to indicate that the first port supports a link discovery capability based on a first clock protocol and the second capability information is used to indicate that the second port supports a link discovery capability based on the first clock protocol, the controller determines that the target strategy includes a link discovery strategy based on the first clock protocol; and/or,

When the first capability information is used to indicate that the first port supports a link discovery capability based on a first discovery protocol and the second capability information is used to indicate that the second port supports a link discovery capability based on the first discovery protocol, the controller determines that the target policy includes a link discovery policy based on the first discovery protocol; and/or,

When the first capability information is used to indicate that the first port supports a link discovery capability based on port traffic statistics and the second capability information is used to indicate that the second port supports a link discovery capability based on port traffic statistics, the controller determines that the target strategy includes a link discovery strategy based on port traffic statistics; and/or,

When the first capability information is used to indicate that the first port supports a link discovery capability based on port alarms and the second capability information is used to indicate that the second port supports a link discovery capability based on port alarms, the controller determines that the target policy includes a link discovery policy based on port alarms.

Optionally, after the controller sends the target policy to the first network device and the second network device, the method also includes: the controller obtains first discovery information and second discovery information, the first discovery information is the discovery information of the cross-domain link between the first network domain and the second network domain (for example, the cross-domain link between the first port of the first network device and the second port of the second network device) obtained by the first network device based on the target policy, and the second discovery information is the discovery information of the cross-domain link between the first network domain and the second network domain obtained by the second network device based on the target policy; the controller determines the cross-domain link between the first network domain and the second network domain based on the first discovery information and the second discovery information.

The technical solution provided by the present application is that the controller determines the target strategy according to the link discovery capability supported by the first port of the first network device and the link discovery capability supported by the second port of the second network device, that is, determines the discovery strategy of the cross-domain link between the first network domain and the second network domain, and the first network device and the second network device respectively obtain the discovery information of the cross-domain link based on the target strategy. Therefore, the process of discovering the cross-domain link does not require human participation and has low requirements for staff.

Optionally, the target strategy includes a link discovery strategy based on a first clock protocol, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port, and the controller determines the cross-domain link between the first network domain and the second network domain according to the first discovery information and the second discovery information, including: the controller determines the first port of the first network device according to the indication information of the first port; the controller determines the second port of the second network device according to the indication information of the second port; the controller determines that the first port corresponds to the second port according to the correspondence. The controller determines that the first port of the first network device corresponds to the second port of the second network device, that is, the controller discovers the cross-domain link between the first port and the second port (that is, the cross-domain link between the first network domain and the second network domain).

Optionally, the target strategy includes a link discovery strategy based on a first discovery protocol, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port, and the controller determines the cross-domain link between the first network domain and the second network domain according to the first discovery information and the second discovery information, including: the controller determines the first port of the first network device according to the indication information of the first port; the controller determines the second port of the second network device according to the indication information of the second port; the controller determines that the first port corresponds to the second port according to the correspondence. The controller determines that the first port of the first network device corresponds to the second port of the second network device, that is, the controller discovers the cross-domain link between the first port and the second port (that is, the cross-domain link between the first network domain and the second network domain).

Optionally, the target strategy includes a link discovery strategy based on port traffic statistics, the first discovery information includes indication information of the first port and a traffic distribution curve of the first port in a first time period, the second discovery information includes indication information of the second port and a traffic distribution curve of the second port in the first time period, and the controller determines the cross-domain link between the first network domain and the second network domain according to the first discovery information and the second discovery information, including: the controller determines the first port of the first network device according to the indication information of the first port; the controller determines the second port of the second network device according to the indication information of the second port; the controller determines that the first port corresponds to the second port according to the traffic distribution curve of the first port in the first time period and the traffic distribution curve of the second port in the first time period. The controller determines that the first port of the first network device corresponds to the second port of the second network device, that is, the controller discovers the cross-domain link between the first port and the second port (that is, the cross-domain link between the first network domain and the second network domain).

Optionally, the target strategy includes a link discovery strategy based on port alarms, the first discovery information includes indication information and disconnection time information of the first port, the disconnection time information is used to indicate that the first port is disconnected within the second time period, the second discovery information includes indication information and alarm time information of the second port, the alarm time information is used to indicate that the second port has an alarm within the second time period, and the controller determines the cross-domain link between the first network domain and the second network domain according to the first discovery information and the second discovery information, including: the controller determines the first port of the first network device according to the indication information of the first port; the controller determines the second port of the second network device according to the indication information of the second port; the controller determines that the first port corresponds to the second port according to the disconnection time information and the alarm time information. The controller determines that the first port of the first network device corresponds to the second port of the second network device, that is, the controller discovers the cross-domain link between the first port and the second port (that is, the cross-domain link between the first network domain and the second network domain).

Optionally, the first discovery information also includes indication information of the first network device, the second discovery information also includes indication information of the second network device, and the controller determines the cross-domain link between the first network domain and the second network domain based on the first discovery information and the second discovery information, and further includes: the controller determines the first network device based on the indication information of the first network device; the controller determines the second network device based on the indication information of the second network device. Since the first discovery information includes the indication information of the first network device and the indication information of the first port, the controller can determine that the first port belongs to the first network device based on the first discovery information; since the second discovery information includes the indication information of the second network device and the indication information of the second port, the controller can determine that the second port belongs to the second network device based on the second discovery information.

Optionally, the controller is a cross-domain controller, and the controller obtains first capability information and second capability information, including: the controller receives first capability information sent by a first controller, and the first controller is a controller of a first network domain; the controller receives second capability information sent by a second controller, and the second controller is a controller of a second network domain.

Optionally, the cross-domain controller, the first controller and the second controller are three different controllers.

Optionally, at least two of the cross-domain controller, the first controller, and the second controller are one controller. For example, the cross-domain controller is one controller, and the first controller and the second controller are one controller; or, the cross-domain controller, the first controller, and the second controller are one controller.

Optionally, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain.

Optionally, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain.

In a third aspect, a link discovery device is provided, which is applied to a controller and includes modules for executing the link discovery method provided in the first aspect or any optional manner of the first aspect.

In a fourth aspect, a link discovery device is provided, which is applied to a controller and includes modules for executing the link discovery method provided in the second aspect or any optional manner of the second aspect.

The modules of the third and fourth aspects mentioned above may be implemented based on software, hardware or a combination of software and hardware, and the modules may be arbitrarily combined or divided based on specific implementations.

In the fifth aspect, a link discovery device is provided, comprising a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program stored in the memory so that the link discovery device performs a link discovery method provided in the first aspect or any optional method of the first aspect.

In the sixth aspect, a link discovery device is provided, comprising a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program stored in the memory so that the link discovery device performs a link discovery method provided in the second aspect or any optional method of the second aspect.

In the seventh aspect, a link discovery system is provided, including a controller, a first network device and a second network device, the first network device is in a first network domain, the second network device is in a second network domain, the network type of the first network domain is different from the network type of the second network domain, and the controller includes a link discovery device as provided in any one of the third to sixth aspects above.

Optionally, the controller is a cross-domain controller, and the system further includes a first controller and a second controller, the first controller is a controller of a first network domain, and the second controller is a controller of a second network domain.

Optionally, the cross-domain controller, the first controller and the second controller are three different controllers.

Optionally, at least two of the cross-domain controller, the first controller, and the second controller are one controller. For example, the cross-domain controller is one controller, and the first controller and the second controller are one controller; or, the cross-domain controller, the first controller, and the second controller are one controller.

Optionally, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain.

Optionally, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain.

In an eighth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program. When the program is executed, the link discovery method provided by the first aspect or any optional method of the first aspect is implemented; or, the link discovery method provided by the second aspect or any optional method of the second aspect is implemented.

In the ninth aspect, a computer program product is provided, which includes a program or code, and when the program or code is executed, it implements the link discovery method provided by the first aspect or any optional method of the first aspect; or, it implements the link discovery method provided by the second aspect or any optional method of the second aspect.

In the tenth aspect, a chip is provided, which includes a programmable logic circuit and/or program instructions, and when the chip is running, it is used to implement the link discovery method provided by the first aspect or any optional method of the first aspect; or, to implement the link discovery method provided by the second aspect or any optional method of the second aspect.

For the technical effects of the third to tenth aspects mentioned above, please refer to the technical effects of the first to second aspects and will not be elaborated here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a communication network provided in an embodiment of the present application;

FIG2 is a schematic diagram of another communication network provided in an embodiment of the present application;

FIG3 is a flow chart of a link discovery method provided by an embodiment of the present application;

FIG4 is a schematic diagram of a PTP header provided in an embodiment of the present application;

FIG5 is a flow chart of another link discovery method provided in an embodiment of the present application;

FIG6 is an interaction diagram of a link discovery method provided in an embodiment of the present application;

7 is a flowchart of another link discovery method provided in an embodiment of the present application;

FIG8 is a flowchart of another link discovery method provided in an embodiment of the present application;

FIG9 is an interaction diagram of another link discovery method provided in an embodiment of the present application;

FIG10 is a schematic diagram of a link discovery device provided in an embodiment of the present application;

11 is a schematic diagram of another link discovery device provided in an embodiment of the present application;

FIG. 12 is a schematic diagram of another link discovery device provided in an embodiment of the present application.

Detailed ways

The implementation methods of the present application will be further described below in conjunction with the accompanying drawings.

A cross-domain link refers to a communication link between different network domains. For example, the communication link between the optical network domain and the Internet Protocol (IP) network domain is a cross-domain link, which is also called a pigtail.

In the process of network maintenance, troubleshooting, network cutover, etc. of the communication network, it is often necessary to obtain the network topology of the communication network, which requires the controller to discover the cross-domain links in the communication network. In traditional network maintenance, staff often use documents to record the cross-domain links in the communication network in the early stage of network construction. However, the errors recorded by the staff are large, such as recording errors and omissions in recording some cross-domain links, which results in a lot of time required to confirm cross-domain links in subsequent network maintenance, troubleshooting, network cutover and other stages. And if the network scale is large, the workload of the staff to record cross-domain links is large, which makes the document maintenance difficult or even impossible to maintain.

Currently, there are a variety of link discovery solutions that can be used to discover cross-domain links, including LLDP-based link discovery solutions, port traffic statistics-based link discovery solutions, and port alarm-based link discovery solutions, which are introduced below.

In the LLDP-based link discovery scheme, cross-domain links are discovered through LLDP. However, this link discovery scheme requires that network devices in different network domains support LLDP, which limits the application scenarios of the link discovery scheme and has poor universality. For example, if the cross-domain link between the optical network domain and the IP network domain is discovered through LLDP, the client-side board of the optical network device (that is, the board in the optical network device used to connect to the IP network domain) needs to support LLDP. Currently, only a few client-side boards of optical network devices support LLDP, and most client-side boards of optical network devices do not support LLDP, resulting in that the LLDP-based link discovery scheme cannot be used to discover the cross-domain link between the optical network domain and the IP network domain in most scenarios.

In the link discovery solution based on port traffic statistics, cross-domain links are discovered based on the network traffic distribution of different network ports in different network domains (that is, the network ports of network devices in different network domains) in the same time period. However, if the network traffic distribution of multiple different network ports in the same time period is consistent or slightly different, it will be difficult to discover cross-domain links, requiring manual assistance in judgment, or even making it impossible to discover cross-domain links.

In the link discovery scheme based on port alarm, the cross-domain link is discovered by disconnecting the communication link corresponding to a certain network port and determining the network port that generates an alarm after disconnecting the communication link. For example, the network port of the optical network device and the network port of the IP network device are both provided with Laser, by turning off the laser of a certain network port of the optical network device, and determining the IP network port (that is, the network port of the IP network device) where an alarm occurs after the laser of the certain network port is turned off, it is determined that there is a cross-domain link between the certain network port and the IP network port where the alarm occurs. However, disconnecting the communication link corresponding to the network port (for example, turning off the laser of a certain network port) is likely to affect the operation of the business carried by the communication link. For example, if a certain communication link has no protection link (or called a standby link or backup link), disconnecting the communication link will cause the business carried by the communication link to be interrupted. Therefore, this link discovery solution is only applicable to scenarios where there is a protection link in the communication link.

The above three link discovery schemes are all scenario-limited and have poor universality. It is usually necessary to select different link discovery schemes from the above three link discovery schemes in combination with the actual network conditions to discover cross-domain links. At present, the staff selects the link discovery scheme from the above three link discovery schemes according to the network conditions of the communication network to discover the cross-domain links in the communication network. This requires the staff to be familiar with the network conditions of the communication network, which places high demands on the staff. For example, if the link discovery scheme based on LLDP discovers the cross-domain link between the optical network domain and the IP network domain, the staff needs to be familiar with which network devices in the optical network domain support LLDP. If the link discovery scheme based on port traffic statistics discovers the cross-domain link between the optical network domain and the IP network domain, the staff needs to be familiar with the network conditions to assist in judgment. If the link discovery scheme based on port alarms discovers the cross-domain link between the optical network domain and the IP network domain, the staff needs to be familiar with which communication links have protection links.

The present application provides a link discovery solution that can discover cross-domain links based on a clock protocol. Since most network devices support the clock protocol, the link discovery solution can be applied to most network scenarios. The link discovery solution has a wide range of application scenarios, strong universality, and high accuracy. In addition, in the present application, the controller determines the discovery strategy of the cross-domain link based on the link discovery capability supported by the network port, and the network device executes the discovery strategy to discover the cross-domain link. The process of determining the discovery strategy of the cross-domain link and the process of discovering the cross-domain link do not require human participation, and there is no requirement for the operating skills of the staff.

The technical solution of the present application is introduced below, and the application scenario of the present application is first introduced.

The application scenario of the present application provides a communication network, which includes at least two network domains, and the at least two network domains are communicatively connected. For example, a communication link is deployed between the at least two network domains, so that the at least two network domains are communicatively connected. Among them, each of the at least two network domains includes at least one network device, and the at least two network domains are communicatively connected, that is, the network devices in the at least two network domains are communicatively connected, and the communication link between the at least two network domains is also the communication link between the network devices in the at least two network domains, and the communication link between the at least two network domains is called a cross-domain link. In the present application, the network types of the at least two network domains are different, and the network type of each network domain is used to indicate the type of network device in the network domain, and/or, to indicate the type of communication link in the network domain.

In one example, the at least two network domains include an optical network domain and an IP network domain, and the optical network domain and the IP network domain respectively include a plurality of network devices, the network devices in the optical network domain are communicatively connected, the network devices in the IP network domain are communicatively connected, and the network devices in the optical network domain are communicatively connected with the network devices in the IP network domain. Among them, the network type of the optical network domain is an optical network type, and the optical network type is used to indicate that the network devices in the optical network domain are optical network devices, and/or, the optical network type is used for the communication link in the optical network domain to be an optical fiber link. The network type of the IP network domain is an IP network type, and the IP network type is used to indicate that the network devices in the IP network domain are IP network devices, and/or, the IP network type is used to indicate that the communication link in the IP network domain is an IP link. For example, the optical network domain is an OTN, a synchronous digital herarchy (SDH) network, etc. Optical network equipment refers to network equipment that supports optical communication protocols, and optical fiber links refer to communication links that support optical communication protocols. Optical network equipment is also called optical communication equipment, wavelength division equipment, OTN equipment, SDH equipment, etc. For example, optical network equipment is OTN equipment. IP network equipment refers to network equipment that supports IP communication protocols, and IP links refer to communication links that support IP communication protocols. IP network equipment is also called IP communication equipment, data communication equipment, data communication equipment, etc. For example, IP network equipment is switches and routers that support IP communication protocols.

In another example, the at least two network domains include a wireless network domain and a wired network domain, the wireless network domain and the wired network domain respectively include multiple network devices, the network devices in the wireless network domain are communicatively connected, the network devices in the wired network domain are communicatively connected, and the network devices in the wireless network domain are communicatively connected to the network devices in the wired network domain.

Among them, the network type of the wireless network domain is a wireless network type, and the wireless network type is used to indicate that the network equipment in the wireless network domain is a wireless network equipment, and/or, the wireless network type is used for the communication link in the wireless network domain is a wireless link. The network type of the wired network domain is a wired network type, and the wired network type is used to indicate that the network equipment in the wired network domain is a wired network equipment, and/or, the wired network type is used to indicate that the communication link in the wired network domain is a wired link. For example, the wireless network domain is a base station subsystem, which includes a wireless base station and a wireless communication device connected to the wireless base station, the wireless network device refers to a network device that supports a wireless communication protocol, and the wireless link refers to a communication link that supports a wireless communication protocol, for example, the wireless network device is a wireless base station, a wireless gateway, etc. The wired network domain can be a bearer network, the wired network device refers to a network device that supports a wired communication protocol, and the wired link refers to a network device that supports a wired communication protocol. The communication link of the protocol, wired network equipment is also called fixed network equipment, and wired network equipment can be switches, routers, etc.

In an embodiment of the present application, the communication network also includes at least one controller, each controller is connected in communication with at least one network device in the communication network to control the at least one network device. Optionally, the at least one controller includes a cross-domain controller and at least two intra-domain controllers; each intra-domain controller can be located in a network domain and connected in communication with the network devices in the network domain to control the network devices in the network domain; the cross-domain controller can be located outside the at least two network domains and connected in communication with the at least two intra-domain controllers to control the at least two intra-domain controllers, thereby performing collaborative control between the at least two network domains. In the present application, the at least one controller can work in collaboration with the network devices in the at least two network domains to discover the cross-domain links between the at least two network domains.

For example, Figure 1 is a schematic diagram of a communication network provided in an embodiment of the present application. Figure 1 takes the communication network including network domain 1 and network domain 2 as an example. Network domain 1 includes a controller 100 and network devices 101-102, and the controller 100 is communicatively connected to the network devices 101-102, and the controller 100 is used to control the network devices 101-102. Network domain 2 includes a controller 200 and network devices 201-202, and the controller 200 is communicatively connected to the network devices 201-202, and the controller 200 is used to control the network devices 201-202. The communication network also includes a controller 300, and the controller 300 is communicatively connected to the controllers 100-200 respectively, and the controller 300 is used to control the controllers 100-200, so as to control the network devices 101-102, 201-202 through the controllers 100-200. As shown in Figure 1, network device P1-101 (i.e., network port P1 of network device 101) is connected to network device P2-201 (i.e., network port P2 of network device 201), network port P3-201 (i.e., network port P3 of network device 201) is connected to network port P4-202 (i.e., network port P4 of network device 202), and network port P5-202 (i.e., network port P5 of network device 202) is connected to network port P6-102 (i.e., network port P6 of network device 102). A communication link L1 is deployed between network device 101 and network device 201, one end of the communication link L1 is network port P1-101, and the other end is network port P2-201. A communication link L2 is deployed between network device 102 and network device 202, one end of the communication link L2 is network port P5-202, and the other end is network port P6-102. Both the communication link L1 and the communication link L2 are cross-domain links between the network domain 1 and the network domain 2. In the present application, the controllers 100-300 and the network devices 101-102, 201-202 work together to discover the cross-domain link L1 and the cross-domain link L2.

In an optional embodiment, the controller and the network device work together to discover cross-domain links between different network domains based on the clock protocol. The communication network also includes a clock source, which can be located in a certain network device or can be deployed separately and communicated with at least one network device. The clock source can trigger a clock protocol message based on a clock, and the clock protocol message can be transmitted in the communication network. Network devices in different network domains can obtain link discovery information based on the clock protocol message, and send the link discovery information to the controller. The controller analyzes the link discovery information obtained by network devices in different network domains to determine the cross-domain links between the different network domains. The embodiment of the present application is illustrated by the separate deployment of the clock source. For example, Figure 2 is a schematic diagram of another communication network provided in an embodiment of the present application. On the basis of Figure 1, the communication network shown in Figure 2 also includes a clock source 400, which is connected to the network device 101, and the clock source 400 can generate a clock protocol message based on the clock triggering network device 101. After the network device 101 generates the clock protocol message, it sends the clock protocol message to the network device 201. After receiving the clock protocol message, the network device 201 sends the clock protocol message to the network device 202. After receiving the clock protocol message, the network device 202 sends the clock protocol message to the network device 102. During the transmission of the clock protocol message, the network devices 101, 201, 202 and 102 respectively obtain link discovery information based on the clock protocol message, and send the obtained link discovery information to the controller 300 through the controller 100 or the controller 200. The controller 300 determines the cross-domain link L1 and the cross-domain link L2 according to the link discovery information obtained by the network devices 101, 201, 202 and 102.

For example, the clock source 400 is connected to the network port P0-101 (that is, the network port P0 of the network device 101), and the clock source 400 triggers the clock protocol message A based on the first clock protocol, and the transmission path of the clock protocol message A includes 101->201->202->102. In the process of each network device on the transmission path sending the clock protocol message A to the next hop device of each network device, each network device encapsulates the indication information of the network port of each network device sending the clock protocol message A in the clock protocol message A, and each network device obtains the link discovery information according to the clock protocol message A. For example, the network device 101 receives a clock protocol message A sent by the clock source 400 through the network port P0-101. The network device 101 encapsulates the indication information "P1-101" of the network port P1-101 in the clock protocol message A and then sends the clock protocol message A to the network device 201 through the network port P1-101. The network device 101 obtains link discovery information 1 based on the clock protocol message A. The link discovery information 1 includes the indication information "P1-101" of the network port P1-101 from which the network device 101 sends the clock protocol message A. The network device 201 receives the clock protocol message A sent by the network device 101 through the network port P2-201, and the network device 201 encapsulates the indication information "P3-201" of the network port P3-201 in the clock protocol message A, and then sends the clock protocol message A to the network device 202 through the network port P3-201, and the network device 201 obtains the link discovery information 2 according to the clock protocol message A, and the link discovery information 2 includes the indication information of the network port P2-201 at which the network device 201 receives the clock protocol message A "P2-101" and the correspondence between network port P1-101 and network port P2-201 "P1-101<—>P2-201" (network device 201 determines the correspondence based on network port P2-201 at which network device 201 receives clock protocol message A and indication information "P1-101" of network port P1-101 carried in the clock protocol message A received by network device 201). Network device 202 receives the clock protocol message A sent by network device 201 through network port P4-202. After encapsulating the indication information "P5-202" of network port P5-202 in the clock protocol message A, network device 202 sends the clock protocol message A to network device 102 through network port P5-202. Network device 202 obtains link discovery information 3 based on the clock protocol message A. The link discovery information 3 includes the indication information "P5-202" of network port P5-202 from which network device 202 sends the clock protocol message A. The network device 102 receives the clock protocol message A sent by the network device 202 through the network port P6-102. The network device 102 obtains the link discovery information 4 according to the clock protocol message A. The link discovery information 4 includes the indication information "P6-102" of the network port P6-102 through which the network device 102 receives the clock protocol message A and the correspondence between the network port P5-202 and the network port P6-102 "P5-202<—>P6-102" (the network device 102 determines the correspondence according to the network port P6-102 through which the network device 102 receives the clock protocol message A and the indication information "P5-202" of the network port P5-202 carried in the clock protocol message A received by the network device 102). The controller 300 can determine the network port P1-101 according to the indication information "P1-101" of the network port P1-101 included in the link discovery information 1, determine the network port P2-201 according to the indication information "P2-101" of the network port P2-201 included in the link discovery information 2, and determine that the network port P1-101 corresponds to the network port P2-201 according to the corresponding relationship "P1-101<—>P2-201" included in the link discovery information 2, thereby determining the cross-domain link L1. Similarly, the controller 300 can determine the network port P5-202 according to the indication information "P5-202" of the network port P5-202 included in the link discovery information 3, determine the network port P6-102 according to the indication information "P6-102" of the network port P6-102 included in the link discovery information 4, and determine that the network port P5-202 corresponds to the network port P6-102 according to the corresponding relationship "P5-202<—>P6-102" included in the link discovery information 4, thereby determining the cross-domain link L2.

It should be noted that the technical solution provided by the present application can not only discover cross-domain links, but also discover intra-domain links. For example, the above-mentioned link discovery information 2 may also include the indication information "P3-101" of the network port P3-201 of the network device 201 sending the clock protocol message A. The above-mentioned link discovery information 3 may also include the indication information "P4-202" of the network port P4-202 of the network device 202 receiving the clock protocol message A and the corresponding relationship between the network port P3-201 and the network port P4-202 "P3-201<—>P4-202". The controller 300 can determine the network port P3-201 according to the indication information "P3-101" of the network port P3-201 included in the link discovery information 2, determine the network port P4-202 according to the indication information "P4-202" of the network port P4-202 included in the link discovery information 3, and determine that the network port P3-201 corresponds to the network port P4-202 according to the corresponding relationship "P3-201<—>P4-202" included in the link discovery information 3, thereby determining the communication link between the network device 201 and the network device 202, which is an intra-domain link in the network domain 2.

In an optional embodiment, in the communication network shown in Figures 1 and 2, network device 101 and network device 201 belong to the same geographical domain, network device 102 and network device 202 belong to the same geographical domain, and network device 201 and network device 202 may belong to different geographical domains. The geographical domain described here may be a site, such as a computer room, etc. In one embodiment, one of network domains 1 and 2 is an IP network domain, and the other network domain is an optical network domain, and cross-domain link L1 and cross-domain link L2 are both optical fiber links. For example, network domain 1 is an IP network domain, network domain 2 is an optical network domain, and cross-domain link L1, cross-domain link L2, and the communication link between network device 201 and network device 202 are all optical fiber links. Network device 101 and network device 201 can be deployed in computer room 1, and network device 102 and network device 202 can be deployed in computer room 2. Network device 201 in computer room 1 and network device 202 in computer room 2 are connected by optical fiber link communication, so that network device 201 and network device 202 can communicate, and thus network device 101 in computer room 1 and network device 102 in computer room 2 can communicate. In another embodiment, one of network domains 1 and 2 is a wireless network domain, and the other network domain is a wired network domain, and cross-domain link L1 and cross-domain link L2 are both wired links. For example, network domain 1 is a wireless network domain, network device 101 is a wireless base station, network domain 2 is a wired network domain, and network device 201 is a fixed network device.

In an embodiment of the present application, each controller in the controllers 100-300 may be a functional module deployed in a server, or a server, or a server cluster consisting of several servers, or a cloud computing service center. The controllers 100-300 may be three different controllers, or at least two of the controllers 100-300 may be one controller, for example, the controller 100 and the controller 200 may be the same controller, and the controller 300 may be another controller; or, the controller 100, the controller 200 and the controller 300 may be the same controller. In one implementation, some or all of the controllers 100-300 may be functional modules deployed in one server; for example, the controllers 100-300 may be three functional modules deployed in the same server, or, the controllers 100-200 may be two functional modules deployed in the same server, and the controller 300 may be a functional module deployed in another server. In another implementation, part or all of the controllers 100-300 are servers; for example, the controllers 100-300 are servers, or the controllers 100-200 are servers, and the controller 300 is a functional module deployed in another server. In another implementation, part or all of the controllers 100-300 are server clusters, for example, the controllers 100-300 are servers, or the controllers 100-200 are servers. Belongs to one server cluster, and the controller 300 belongs to another server cluster. In some embodiments, the controller is also called a manager, a network manager, a network controller, etc.

In the embodiment of the present application, the clock source 400 supports at least one clock protocol. For example, the clock source 400 supports at least one of the Institute of Electrical and Electronics Engineers (IEEE) 1588 protocol and the International Telecommunication Union Telecommunication Standardization Sector (ITU-T for ITU Telecommunication Standardization Sector, ITU-T) G.8275.1 protocol. The IEEE 1588 protocol is a protocol defined by IEEE 1588 that can achieve high-precision clock synchronization in measurement and control systems. The IEEE 1588 protocol is also called the 1588 protocol or the precision time protocol (PTP). The full name of the 1588 protocol is: Precision Clock Synchronization Protocol Standard for Network Measurement and Control Systems. The ITU-TG.8275.1 protocol is also called the G.8275.1 protocol. The ITU-TG.8275.1 protocol defines a telecom profile for phase/time synchronization with full timing support from the network. The clock source 400 can trigger the clock protocol message A based on a first clock protocol supported by the clock source 400. For example, the first clock protocol is the IEEE1588 V2 protocol or the ITU-TG.8275.1 protocol. Optionally, the clock source 400 is a building integrated timing supply (BITS) device.

It should be noted that, for the sake of convenience, FIG. 1 and FIG. 2 show two network domains 1 and two controllers 100, and the two network domains 1 are actually the same network domain, and the two controllers 100 are actually the same controller. In addition, the communication network shown in FIG. 1 and FIG. 2 is only used for example, and is not used to limit the technical solution of the embodiment of the present application. In the actual implementation process, the number of network devices, the number of controllers, the number of network domains, the number of clock sources, and the connection relationship between different devices in the communication network can be configured as needed, and the embodiment of the present application does not limit this.

The above is an introduction to the application scenario of the present application. The following is an embodiment of the link discovery method of the present application. For ease of description, in some of the following descriptions, the message based on the first clock protocol is referred to as the first clock protocol message, and the message based on the first discovery protocol is referred to as the first discovery protocol message.

Please refer to Figure 3, which shows a flow chart of a link discovery method provided by an embodiment of the present application. The link discovery method is applied to a communication network including a controller, a first network domain and a second network domain, the network type of the first network domain is different from the network type of the second network domain, and the link discovery method is executed by the controller. For example, the communication network is shown in Figure 1 or Figure 2, one of the first network domain and the second network domain is network domain 1, the other network domain is network domain 2, and the controller is controller 300. Referring to Figure 3, the link discovery method includes the following steps S301 to S302.

S301. The controller obtains first discovery information and second discovery information, the first discovery information is the discovery information of the first link obtained by the first network device based on the clock protocol message B, and the second discovery information is the discovery information of the first link obtained by the second network device based on the clock protocol message B. The first network device is in the first network domain, and the second network device is in the second network domain. The network type of the first network domain is different from the network type of the second network domain, and the first link is a cross-domain link between the first port of the first network device and the second port of the second network device.

The controller receives the first discovery information and the second discovery information, or the controller actively collects the first discovery information and the second discovery information. For example, the controller is a cross-domain controller, the cross-domain controller receives the first discovery information sent by the first controller, and the cross-domain controller receives the second discovery information sent by the second controller, the first controller is a controller of the first network domain, and the second controller is a controller of the second network domain. For example, the first controller is located in the first network domain, and the second controller is located in the second network domain. The cross-domain controller, the first controller, and the second controller can be three different controllers (that is, three independent controllers). Or, at least two of the cross-domain controller, the first controller, and the second controller are one controller. The network type of the first network domain is different from the network type of the second network domain; in one example, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain; in another example, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain.

Different network devices in a communication network can synchronize their clocks by transmitting clock protocol message B. The first network device and the second network device are two network devices in the communication network, so the first network device and the second network device can transmit the clock protocol message B. The first network device can obtain first discovery information based on the clock protocol message B during the process of transmitting (e.g., sending or receiving) the clock protocol message B. The second network device can obtain second discovery information based on the clock protocol message B during the process of transmitting (e.g., sending or receiving) the clock protocol message B. In one embodiment, after the first network device obtains the first discovery information, it sends the first discovery information to the first controller, and the first controller sends the first discovery information to the cross-domain controller; after the second network device obtains the second discovery information, it sends the second discovery information to the second controller, and the second controller sends the second discovery information to the cross-domain controller. In another embodiment, the first controller periodically collects link discovery information (e.g., first discovery information) from the first network device, and sends the first discovery information to the cross-domain controller; the second controller periodically collects link discovery information (e.g., second discovery information) from the second network device, and sends the second discovery information to the cross-domain controller. The first controller and the second network device can periodically collect link discovery information (e.g., second discovery information) from the second network device, and send the second discovery information to the cross-domain controller. The period for the second controller to collect link discovery information can be equal to the period for sending clock protocol messages. Optionally, the first network device sends the first discovery information to the first controller via the border gateway protocol (BGP), the network configuration protocol (NETCONF), the path computation element communication protocol (PCEP), the telemetry protocol, the Qx protocol (a protocol for communication between the host software and the network management device), or other private protocols; and/or, the second network device sends the second discovery information to the second controller via BGP, NETCONF, PCEP, the telemetry protocol, the Qx protocol, or other private protocols, which is not limited in the embodiments of the present application.

In an embodiment of the present application, the first discovery information includes indication information of a first port of a first network device, the second discovery information includes indication information of a second port of a second network device, and at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port. For example, the correspondence between the first port and the second port is a correspondence between the indication information of the first port and the indication information of the second port. In one embodiment, the indication information of the first port is a port identifier of the first port, and the indication information of the second port is a port identifier of the second port. The first discovery information may also include indication information of the first network device to indicate the first network device, so that the first discovery information indicates that the first port belongs to the first network device, and the second discovery information may also include indication information of the second network device to indicate the second network device, so that the second discovery information indicates that the second port belongs to the second network device. For example, as shown in FIG. 1 or FIG. 2, the first network device is network device 101, the first port is network port P1, the second network device is network device 201, and the second port is network port P2, then the first discovery information includes the indication information "P1" of the first port and the indication information "101" of the first network device, and the second discovery information includes the indication information "P2" of the second port and the indication information "201" of the second network device. In another embodiment, the indication information of the first port includes the indication information of the first network device and the port identifier of the first port (for example, the indication information of the first port is composed of the indication information of the first network device and the port identifier of the first port), and the indication information of the first port is used to indicate the first port and to indicate that the first port belongs to the first network device; the indication information of the second port includes the indication information of the second network device and the port identifier of the second port (for example, the indication information of the second port is composed of the indication information of the second network device and the port identifier of the second port), and the indication information of the second port is used to indicate the second port and to indicate that the second port belongs to the second network device. For example, as shown in FIG. 1 or FIG. 2, the first network device is network device 101, the first port is network port P1, the second network device is network device 201, and the second port is network port P2, then the first discovery information includes the indication information "P1-101" of the first port, and the second discovery information includes the indication information "P2-201" of the second port. The indication information of the first port is composed of the indication information "101" of the first network device and the port identifier "P1" of the first port, and the indication information of the second port is composed of the indication information "201" of the second network device and the port identifier "P2" of the second port. The above description of the port indication information (such as the indication information of the first port) and the device indication information (such as the indication information of the first network device) is only for example, and the port indication information can be any identification information that can be used to indicate the port, such as the port number, the media access control (MAC) address of the port. The device indication information can be a device identification, such as the address of the device, the serial number of the device, and any identification information that can be used to indicate the network device.

In one embodiment, the first network device and the second network device are two network devices on the transmission path of the clock protocol message B, and the second network device is the next hop device of the first network device. The first network device sends the clock protocol message B to the second network device through the first port, and the second network device receives the clock protocol message B through the second port. Then the first port is the network port through which the first network device sends the clock protocol message B, and the second port is the network port through which the second network device receives the clock protocol message B. The clock protocol message B sent by the first network device to the second network device carries the indication information of the first port. The first network device generates the first discovery information according to the network port (that is, the first port) through which the first network device sends the clock protocol message B, and the second network device generates the second discovery information according to the network port (that is, the second port) through which the second network device receives the clock protocol message B and the indication information of the first port carried by the clock protocol message B. The first discovery information includes the indication information of the first port, and the second discovery information includes the indication information of the second port and the corresponding relationship between the first port and the second port. Take the example that the indication information of the first port includes the indication information of the first network device and the port identifier of the first port, and the indication information of the second port includes the indication information of the second network device and the port identifier of the second port. As shown in FIG1 or FIG2, the first network device is the network device 101, the first port is the network port P1, the second network device is the network device 201, and the second port is the network port P2, then the first discovery information includes the indication information "P1-101" of the first port, the second discovery information includes the indication information "P2-201" of the second port, and the corresponding relationship "P1-101<—>P2-201" between the indication information "P1-101" of the first port and the indication information "P2-201" of the second port.

In another embodiment, the first network device and the second network device are two network devices on the transmission path of the clock protocol message B, and the first network device is the next-hop device of the second network device. The second network device sends the clock protocol message B to the first network device through the second port, and the first network device receives the clock protocol message B through the first port. The second port is the network port through which the second network device sends the clock protocol message B, and the first port is the network port through which the first network device receives the clock protocol message B. The clock protocol message B sent by the second network device to the first network device carries the indication information of the second port. The second network device generates the second discovery information according to the network port (i.e., the second port) through which the second network device sends the clock protocol message B, and the first network device generates the second discovery information according to the network port (i.e., the second port) through which the first network device receives the clock protocol message B. The first discovery information is generated based on the network port (i.e., the first port) of the clock protocol message B and the indication information of the second port carried by the clock protocol message B. The first discovery information includes the indication information of the first port and the corresponding relationship between the first port and the second port, and the second discovery information includes the indication information of the second port. Take the example that the indication information of the first port includes the indication information of the first network device and the port identifier of the first port, and the indication information of the second port includes the indication information of the second network device and the port identifier of the second port. As shown in FIG. 1 or FIG. 2, the first network device is the network device 101, the first port is the network port P1, the second network device is the network device 201, and the second port is the network port P2. Then, the first discovery information includes the indication information "P1-101" of the first port and the corresponding relationship "P1-101<—>P2-201" between the indication information "P1-101" of the first port and the indication information "P2-201" of the second port, and the second discovery information includes the indication information "P2-201" of the second port.

The clock protocol message B in the present application is a message based on the first clock protocol (i.e., the first clock protocol message), and the first clock protocol is any possible clock protocol such as the IEEE1588 protocol, the ITU-TG.8275.1 protocol, etc. The source end (or constructor) of the clock protocol message B can be a clock source or a network device (e.g., a first network device or a second network device). For example, the first clock protocol is the IEEE1588 protocol, the clock protocol message B is also called a PTP message, and the message header of the clock protocol message B is also called a PTP header, and the PTP header includes a source port identification (source port identity) field. In the process of each network device along the way of the clock protocol message B sending the clock protocol message B to the next hop device of each network device, each network device adds the indication information of the network port of each network device sending the clock protocol message B, the indication information of each network device, etc. in the source port identification field, for example, the information carried in the source port identification field is replaced with the indication information of the network port of each network device sending the clock protocol message B, the indication information of each network device, etc. In an embodiment where the second network device is a next-hop device of the first network device, in the clock protocol message B sent by the first network device to the second network device, the indication information of the first port is located in the source port identification field. In an embodiment where the first network device is a next-hop device of the second network device, in the clock protocol message B sent by the second network device to the first network device, the indication information of the second port is located in the source port identification field. For example, the structure of the PTP header is shown in FIG4. The PTP header includes the following fields: transport specific, message type, reserved, PTP version, message length, domain number, flag field, correction field, source port identity, sequence ID, control field, log message interval. In Figure 4: the length value corresponding to each line in the PTP header represents the length of each line of fields, and the unit of the length value is octets; the offset value corresponding to each line in the PTP header represents the offset of the starting position of each line of fields from the first byte of the clock protocol message where the PTP header is located, and the unit of the offset value is byte. The length of the source port identification field is 10 bytes, and the source port identification field is used to carry the relevant attributes of the sending port of the clock protocol message. For example, the first network device sends a clock protocol message B to the second network device through the first port, and the source port identification field in the clock protocol message B sent by the first network device carries the indication information of the first port. For the meaning of the fields such as transmission characteristics, message type, PTP version, message length, domain sequence number, flag field, correction field, sequence identification, control field, logarithmic message interval, etc. in Figure 4, please refer to the relevant standard documents, which will not be repeated here.

S302: The controller determines a first link according to the first discovery information and the second discovery information.

In an optional embodiment, the first discovery information includes indication information of the first port of the first network device, the second discovery information includes indication information of the second port of the second network device, and at least one of the first discovery information and the second discovery information includes the correspondence between the first port and the second port. The controller determines the first port of the first network device based on the indication information of the first port, the controller determines the second port of the second network device based on the indication information of the second port, and the controller determines that the first port corresponds to the second port based on the correspondence between the first port and the second port. The controller determines that the first port corresponds to the second port, that is, the controller determines that there is a communication link between the first port and the second port, and the communication link is the first link. The first link is a cross-domain link between the first network domain and the second network domain.

In one embodiment, the indication information of the first port is the port identifier of the first port, the indication information of the second port is the port identifier of the second port, the first discovery information also includes the indication information of the first network device, and the second discovery information also includes the indication information of the second network device. The controller determines the first network device according to the indication information of the first network device included in the first discovery information, and the controller determines the first port according to the indication information of the first port included in the first discovery information, so that the controller determines that the first port belongs to the first network device according to the first discovery information (that is, the controller determines the first port of the first network device according to the first discovery information). The controller determines the second network device according to the indication information of the second network device included in the second discovery information, and the controller determines the second port according to the indication information of the second port included in the second discovery information, so that the controller determines that the second port belongs to the second network device according to the second discovery information (that is, the controller determines the second port of the second network device according to the second discovery information). And, the controller determines that the first port of the first network device corresponds to the second port of the second network device according to the correspondence between the first port and the second port included in the first discovery information and/or the second discovery information, so that the controller determines that there is a cross-domain link (that is, the first link) between the first port of the first network device and the second port of the second network device. For example, as shown in Figure 1 or Figure 2, The first network device is the network device 101, the first port is the network port P1, the second network device is the network device 201, the second port is the network port P2, the first discovery information includes the indication information "P1" of the first port and the indication information "101" of the first network device, the second discovery information includes the indication information "P2" of the second port and the indication information "201" of the second network device, and the second discovery information includes the corresponding relationship "P1<—>P2" between the indication information "P1" of the first port and the indication information "P2" of the second port. The controller determines the first network device 101 according to the indication information "101" of the first network device included in the first discovery information, and the controller determines the first port P1 according to the indication information "P1" of the first port included in the first discovery information, so that the controller determines that the first port P1 belongs to the first network device 101 according to the first discovery information. The controller determines the second network device 201 according to the indication information "201" of the second network device included in the second discovery information, and the controller determines the second port P2 according to the indication information "P2" of the second port included in the second discovery information, so that the controller determines that the second port P2 belongs to the second network device 201 according to the second discovery information. And, the controller determines that the first port P1 of the first network device corresponds to the second port P2 of the second network device according to the correspondence relationship “P1<—>P2” between the indication information “P1” of the first port and the indication information “P2” of the second port included in the second discovery information.

In another embodiment, the indication information of the first port includes the indication information of the first network device and the port identifier of the first port, and the indication information of the second port includes the indication information of the second network device and the port identifier of the second port. The controller determines the first port according to the indication information of the first port included in the first discovery information and determines that the first port belongs to the first network device. The controller determines the second port according to the indication information of the second port included in the second discovery information and determines that the second port belongs to the second network device. And, the controller determines that the first port of the first network device corresponds to the second port of the second network device according to the correspondence between the first port and the second port included in the first discovery information and/or the second discovery information, so that the controller determines that there is a cross-domain link (i.e., the first link) between the first port of the first network device and the second port of the second network device. For example, as shown in Figure 1 or Figure 2, the first network device is network device 101, the first port is network port P1, the second network device is network device 201, the second port is network port P2, the first discovery information includes the indication information "P1-101" of the first port, the second discovery information includes the indication information "P2-201" of the second port, and the correspondence "P1-101<—>P2-201" between the indication information "P1-101" of the first port and the indication information "P2-201" of the second port. The controller determines the first port P1 of the first network device 101 according to the indication information "P1-101" of the first port included in the first discovery information; the controller determines the second port P2 of the second network device 201 according to the indication information "P2-201" of the second port included in the second discovery information; and, the controller determines that the first port P1 of the first network device (i.e., network device 101) corresponds to the second port P2 of the second network device (i.e., network device 201) according to the correspondence relationship "P1-101<—>P2-201" between the indication information "P1-101" of the first port and the indication information "P2-201" of the second port included in the second discovery information.

In summary, in the link discovery method provided by the embodiment of the present application, the first network device in the first network domain and the second network device in the second network domain obtain link discovery information based on the clock protocol message, and the controller determines the cross-domain link between the first port of the first network device and the second port of the second network device based on the link discovery information obtained by the first network device and the second network device. That is, in the embodiment of the present application, the controller and the network device work together to discover cross-domain links based on the clock protocol. Since most network devices support the clock protocol, for example, 90% of the network devices in the existing network support the clock protocol, the link discovery solution provided by the embodiment of the present application can be applied to most network scenarios, the link discovery solution has a wide range of application scenarios, strong universality, and the link discovery solution has a high accuracy in discovering cross-domain links.

In an optional embodiment, please refer to Figure 5, which shows a flow chart of another link discovery method provided in an embodiment of the present application. As shown in Figure 5, before S301, the method further includes the following step S303.

S303. The controller sends a target policy to the first network device and the second network device, where the target policy is used to instruct the first network device and the second network device to discover a cross-domain link between the first network domain and the second network domain based on the first clock protocol.

Since the target policy is used to instruct the first network device and the second network device to discover the cross-domain link between the first network domain and the second network domain based on the first clock protocol, the target policy is also called a link discovery policy based on the first clock protocol. The clock protocol message B described in S301 is a message based on the first clock protocol (i.e., the first clock protocol message). After the controller sends the target policy to the first network device and the second network device, during the process of transmitting the clock protocol message B, the first network device and the second network device respectively obtain link discovery information based on the target policy and the clock protocol message B to discover the cross-domain link between the first network domain and the second network domain.

In one embodiment, the controller is a cross-domain controller, and the cross-domain controller, the first controller, and the second controller are three independent controllers. The cross-domain controller controls the first network domain through the first controller, and the cross-domain controller controls the second network domain through the second controller. The cross-domain controller sends the target policy to the first network device through the first controller, and the cross-domain controller sends the target policy to the second network device through the second controller. For example, the cross-domain controller sends the target policy to the first controller and the second controller respectively, and after receiving the target policy, the first controller sends the target policy to the first network device, and after receiving the target policy, the second controller sends the target policy to the second network device.

In another embodiment, the controller is a cross-domain controller, the cross-domain controller, the first controller and the second controller are the same controller, the cross-domain controller directly controls the first network domain and the second network domain, the cross-domain controller directly sends the target policy to the first network device, and the cross-domain controller directly sends the target policy to the second network device.

In an optional embodiment, the controller sends indication information for indicating a target policy to the first network device and the second network device (the application refers to the indication information for indicating a target policy as target policy information). The target policy information may include indication information of the first clock protocol (e.g., protocol number), indication information of the first port of the first network device, indication information of the second port of the second network device, etc. The first network device determines the first port according to the indication information of the first port of the first network device included in the target policy information, determines the first clock protocol according to the indication information of the first clock protocol included in the target policy information, and the first network device obtains link discovery information based on the first clock protocol message in the process of transmitting (e.g., sending or receiving) the first clock protocol message through the first port. Similarly, the second network device determines the second port according to the indication information of the second port of the second network device included in the target policy information, determines the first clock protocol according to the indication information of the first clock protocol included in the target policy information, and the second network device obtains link discovery information based on the first clock protocol message in the process of transmitting (e.g., sending or receiving) the first clock protocol message through the second port.

In an optional embodiment, before the controller sends the target policy to the first network device and the second network device, the controller determines the target policy according to the link discovery capability supported by the first port of the first network device and the link discovery capability supported by the second port of the second network device. Please continue to refer to Figure 5. Before S303, the method also includes the following steps S304 to S305.

S304. The controller obtains first capability information and second capability information, the first capability information is used to indicate that the first port of the first network device supports the first clock protocol, and the second capability information is used to indicate that the second port of the second network device supports the first clock protocol.

The first capability information includes capability information of the first port, and the capability information of the first port is used to indicate that the first port supports the first clock protocol (that is, the link discovery capability supported by the first port includes the link discovery capability based on the first clock protocol). The second capability information includes capability information of the second port, and the capability information of the second port is used to indicate that the second port supports the first clock protocol (that is, the link discovery capability supported by the second port includes the link discovery capability based on the first clock protocol). For example, the first capability information and the second capability information respectively include indication information of the first clock protocol.

The controller may receive the first capability information and the second capability information, or the controller actively collects the first capability information and the second capability information. For example, the controller is a cross-domain controller, the cross-domain controller receives the first capability information sent by the first controller, and the cross-domain controller receives the second capability information sent by the second controller. Optionally, the first network device sends the port capability information (e.g., the first capability information) of the first network device to the first controller in real time, periodically, or based on event triggering (e.g., the link discovery capability of the first port changes, the network topology of the first network domain and/or the second network domain changes), and the first controller sends the port capability information to the cross-domain controller after receiving the port capability information of the first network device. The second network device sends the port capability information (e.g., the second capability information) of the second network device to the second controller in real time, periodically, or based on event triggering (e.g., the link discovery capability of the second port changes, the network topology of the first network domain and/or the second network domain changes), and the second controller sends the port capability information to the cross-domain controller after receiving the port capability information of the second network device. For example, the first network device sends the first capability information to the first controller through BGP, NETCONF, PCEP, telemetry protocol or other private protocols; and/or, the second network device sends the first capability information to the second controller through BGP, NETCONF, PCEP, telemetry protocol, Qx protocol or other private protocols. Among them, the port capability information of the first network device includes the capability information of the first port, and may also include the capability information of other network ports of the first network device; in this embodiment, the port capability information of the first network device may include at least one set of correspondences, and each set of correspondences in the at least one set of correspondences includes the indication information of a network port of the first network device and the capability information of the one network port. Similarly, the port capability information of the second network device includes the capability information of the second port, and may also include the capability information of other network ports of the second network device; in this embodiment, the port capability information of the second network device may include at least one set of correspondences, and each set of correspondences in the at least one set of correspondences includes the indication information of a network port of the second network device and the capability information of the one network port.

S305: The controller determines a target strategy according to the first capability information and the second capability information.

The controller determines that the first port of the first network device supports the first clock protocol based on the first capability information, and the controller determines that the second port of the second network device supports the first clock protocol based on the second capability information. The controller determines a target policy based on that both the first port and the second port support the first clock protocol, and the target policy is a link discovery policy based on the first clock protocol.

In an optional embodiment, the controller determines that the first network device and the second network device are at the same site (for example, the same computer room), and the controller determines that the target strategy is a link discovery strategy based on the first clock protocol based on the fact that the first network device and the second network device are at the same site and that both the first port and the second port support the first clock protocol.

It should be noted that a network port may support multiple link discovery capabilities. If the controller is a cross-domain link in the same site, The two network ports at the end determine different link discovery strategies, which may result in the inability to discover the cross-domain link in the end. Therefore, when the controller determines the target strategy, the controller first determines that the first network device and the second network device are in the same site, and then the controller determines the target strategy based on the first port of the first network device and the second port of the second network device. In this way, the controller determines the same link discovery strategy for the two network ports at both ends of the same cross-domain link in the same site, and the network devices where the two network ports are located can discover the cross-domain link according to the link discovery strategy.

Please refer to Figure 6, which shows an interaction diagram of a link discovery method provided by an embodiment of the present application. As shown in Figure 6, the method includes the following steps S601 to S617.

S601. A first network device sends first capability information to a first controller, where the first capability information is used to indicate that a first port of the first network device supports a first clock protocol.

The first network device is in the first network domain, and the first controller is the controller of the first network domain.

S602. The first controller sends first capability information to the cross-domain controller.

S603. The second network device sends second capability information to the second controller, where the second capability information is used to indicate that the second port of the second network device supports the first clock protocol.

The second network device is in the second network domain, and the second controller is a controller of the second network domain. The network type of the first network domain is different from the network type of the second network domain. For example, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain.

S604. The second controller sends second capability information to the cross-domain controller.

S605. The cross-domain controller determines a target policy according to the first capability information and the second capability information, where the target policy is used to instruct to discover a cross-domain link between the first network domain and the second network domain based on the first clock protocol.

S606. The cross-domain controller sends the target policy to the first controller and the second controller respectively.

S607. The first controller sends the target policy to the first network device.

S608. The second controller sends the target policy to the second network device.

S609. The first network device sends a clock protocol message B to the second network device through the first port, where the clock protocol message B carries indication information of the first port.

The clock protocol message B is a message based on the first clock protocol, that is, the first clock protocol message.

In one embodiment, the source end (or constructor) of the clock protocol message B is a first network device, the first network device generates the clock protocol message B, and sends the clock protocol message B to the second network device through the first port.

In another embodiment, the source end of the clock protocol message B is a clock source or a network device before the first network device. The first network device receives the clock protocol message B from the previous-hop device of the first network device. After the first network device encapsulates the indication information of the first port in the clock protocol message B, it sends the clock protocol message B to the second network device through the first port.

S610. The first network device obtains first discovery information based on the clock protocol message B, where the first discovery information includes indication information of the first port.

The first network device acquires the first discovery information according to the network port (ie, the first port) through which the first network device sends the clock protocol message B. The first discovery information includes indication information of the first port and may also include indication information of the first network device.

S611. The first network device sends first discovery information to the first controller.

S612. The first controller sends first discovery information to the cross-domain controller.

S613. The second network device receives clock protocol message B through the second port.

S614. The second network device obtains second discovery information based on the clock protocol message B, where the second discovery information includes indication information of the second port and a correspondence between the first port and the second port.

The second network device can obtain the second discovery information based on the network port (i.e., the second port) at which the second network device receives the clock protocol message B and the indication information of the first port carried by the clock protocol message B received by the second network device. The second discovery information includes the indication information of the second port and the correspondence between the first port and the second port, and may also include the indication information of the second network device. The correspondence between the first port and the second port may be the correspondence between the indication information of the first port and the indication information of the second port. For example, the second network device obtains the indication information of the second port based on the second port at which the second network device receives the clock protocol message B; the second network device obtains the correspondence between the first port and the second port based on the indication information of the second port and the indication information of the first port carried by the clock protocol message B.

S615. The second network device sends second discovery information to the second controller.

S616. The second controller sends second discovery information to the cross-domain controller.

S617. The cross-domain controller determines a first link according to the first discovery information and the second discovery information, where the first link is a cross-domain link between the first port and the second port.

The detailed implementation process of the above S601 to S617 can refer to the embodiments shown in Figures 3 and 5, and will not be repeated here.

Please refer to Figure 7, which shows a flowchart of another link discovery method provided by an embodiment of the present application. The link discovery method is applied to a communication network including a controller, a first network domain and a second network domain. The network type of the first network domain is different from the network type of the second network domain, and the link discovery method is executed by the controller. For example, the communication network is shown in Figure 1 or Figure 2, one of the first network domain and the second network domain is network domain 1, the other network domain is network domain 2, and the controller is controller 300. Referring to Figure 7, the link discovery method includes the following steps S701 to S703.

S701. The controller obtains first capability information and second capability information, the first capability information is used to indicate the link discovery capability supported by the first port of the first network device, and the second capability information is used to indicate the link discovery capability supported by the second port of the second network device, the first network device is in the first network domain, the second network device is in the second network domain, and the network type of the first network domain is different from the network type of the second network domain.

Among them, the first capability information includes the capability information of the first port, and the capability information of the first port is used to indicate the link discovery capability supported by the first port. The second capability information includes the capability information of the second port, and the capability information of the second port is used to indicate the link discovery capability supported by the second port. In the present application, the link discovery capability supported by the first port and the link discovery capability supported by the second port respectively include at least one of the following: a link discovery capability based on the first clock protocol, a link discovery capability based on the first discovery protocol, a link discovery capability based on port traffic statistics, and a link discovery capability based on port alarms. Among them, a certain network port supporting a link discovery capability based on the first clock protocol can also be called that the certain network port supports the first clock protocol; a certain network port supporting a link discovery capability based on the first discovery protocol can also be called that the certain network port supports the first discovery protocol; a certain network port supporting a link discovery capability based on port traffic statistics can also be called that the certain network port supports port traffic statistics; a certain network port supporting a link discovery capability based on port alarms can also be called that the certain network port supports port alarms; therefore, the first port and the second port respectively support at least one of the first clock protocol, the first discovery protocol, port traffic statistics, and port alarms. Among them, the first clock protocol is the IEEE1588 protocol, the ITU-T G.8275.1 protocol or other clock protocols. The first discovery protocol is LLDP or other link discovery protocols. A certain network port supports port traffic statistics, which means that the certain network port can support network traffic statistics on the certain network port, including but not limited to the network device where the certain network port is located counting the network traffic of the certain network port, the monitoring device connected to the certain network port counting the network traffic of the certain network port, etc. A certain network port supports port alarm, which means that the certain network port can generate an alarm after the certain network port goes offline (down). The down of the certain network port can be the down of the communication link with the certain network port as the endpoint. For example, after a certain communication link is disconnected from the network port at one end, the network port at the other end of the certain communication link can generate an alarm. In the example, the first port and the second port respectively support the first clock protocol, the first discovery protocol, port traffic statistics and port alarms, the capability information of the first port includes indication information of the first clock protocol, indication information of the first discovery protocol, port traffic statistics indication information (the port traffic statistics indication information is used to indicate that the first port supports port traffic statistics) and port alarm indication information (the port alarm indication information is used to indicate that the first port supports port alarms), and the capability information of the second port includes indication information of the first clock protocol, indication information of the first discovery protocol, port traffic statistics indication information and port alarm indication information.

In an embodiment of the present application, the controller may receive the first capability information and the second capability information, or the controller actively collects the first capability information and the second capability information. For example, the controller is a cross-domain controller, the cross-domain controller receives the first capability information sent by the first controller, and the cross-domain controller receives the second capability information sent by the second controller, the first controller is a controller of the first network domain, and the second controller is a controller of the second network domain. For example, the first controller is located in the first network domain, and the second controller is located in the second network domain. Optionally, the first network device sends the port capability information (e.g., the first capability information) of the first network device to the first controller in real time, periodically, or based on event triggering, and the first controller sends the port capability information of the first network device to the cross-domain controller after receiving the port capability information of the first network device. The second network device sends the port capability information (e.g., the second capability information) of the second network device to the second controller in real time, periodically, or based on event triggering, and the second controller sends the port capability information of the second network device to the cross-domain controller after receiving the port capability information of the second network device. For example, the first network device sends the first capability information to the first controller via BGP, NETCONF, PCEP, telemetry protocol, Qx protocol or other private protocols; and/or, the second network device sends the first capability information to the second controller via BGP, NETCONF, PCEP, telemetry protocol or other private protocols. The port capability information of the first network device includes the capability information of the first port, and may also include the capability information of other network ports of the first network device; in this embodiment, the port capability information of the first network device may include at least one set of correspondences, and each set of correspondences in the at least one set of correspondences includes indication information of a network port of the first network device and the capability information of the one network port. The port capability information of the second network device includes the capability information of the second port, and may also include the capability information of other network ports of the first network device. May include capability information of other network ports of the second network device; in this embodiment, the port capability information of the second network device may include at least one set of correspondences, each set of correspondences in the at least one set of correspondences includes indication information of a network port of the second network device and capability information of the one network port. In an embodiment of the present application, the cross-domain controller, the first controller, and the second controller are three different controllers. Alternatively, at least two of the cross-domain controller, the first controller, and the second controller are one controller. The network type of the first network domain is different from the network type of the second network domain; for example, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain; or, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain.

S702: The controller determines a target policy according to the first capability information and the second capability information.

The controller determines the link discovery capability supported by the first port of the first network device according to the first capability information, determines the link discovery capability supported by the second port of the second network device according to the second capability information, and determines the target policy according to the link discovery capability supported by the first port and the link discovery capability supported by the second port. Optionally, the controller determines that the first network device and the second network device are at the same site, and determines the target policy according to the first network device and the second network device being at the same site, the link discovery capability supported by the first port, and the link discovery capability supported by the second port.

In the embodiment of the present application, the target strategy includes at least one of the following: a link discovery strategy based on a first clock protocol, a link discovery strategy based on a first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms. S702 includes at least one of the following four implementations.

The first implementation manner: when the first capability information is used to indicate that the first port supports the link discovery capability based on the first clock protocol and the second capability information is used to indicate that the second port supports the link discovery capability based on the first clock protocol, the controller determines that the target policy includes the link discovery policy based on the first clock protocol. That is, when the controller determines that both the first port and the second port support the first clock protocol, the controller determines that the target policy includes the link discovery policy based on the first clock protocol.

Second implementation: When the first capability information is used to indicate that the first port supports the link discovery capability based on the first discovery protocol and the second capability information is used to indicate that the second port supports the link discovery capability based on the first discovery protocol, the controller determines that the target policy includes the link discovery policy based on the first discovery protocol. That is, when the controller determines that both the first port and the second port support the first discovery protocol, the controller determines that the target policy includes the link discovery policy based on the first discovery protocol.

A third implementation manner: when the first capability information is used to indicate that the first port supports a link discovery capability based on port traffic statistics and the second capability information is used to indicate that the second port supports a link discovery capability based on port traffic statistics, the controller determines that the target policy includes a link discovery policy based on port traffic statistics. That is, when the controller determines that both the first port and the second port support port traffic statistics, the controller determines that the target policy includes a link discovery policy based on port traffic statistics.

Fourth implementation: When the first capability information is used to indicate that the first port supports the link discovery capability based on the port alarm and the second capability information is used to indicate that the second port supports the link discovery capability based on the port alarm, the controller determines that the target policy includes the link discovery policy based on the port alarm. That is, when the controller determines that both the first port and the second port support the port alarm, the controller determines that the target policy includes the link discovery policy based on the port alarm.

The above four implementations can be implemented independently or in combination. In one embodiment, the first port and the second port both support the first clock protocol, the first discovery protocol, port traffic statistics and port alarms, and the controller determines the target strategy to be one of the link discovery strategy based on the first clock protocol, the link discovery strategy based on the first discovery protocol, the link discovery strategy based on port traffic statistics and the link discovery strategy based on port alarms. In one example, the controller determines the target strategy to be any one of the link discovery strategy based on the first clock protocol, the link discovery strategy based on the first discovery protocol, the link discovery strategy based on port traffic statistics and the link discovery strategy based on port alarms. In another example, the controller determines the target strategy to be one of the link discovery strategy based on the first clock protocol, the link discovery strategy based on the first discovery protocol, the link discovery strategy based on port traffic statistics and the link discovery strategy based on port alarms in order (e.g., priority); for example, the priorities of the link discovery strategy based on the first clock protocol, the link discovery strategy based on the first discovery protocol, the link discovery strategy based on port traffic statistics and the link discovery strategy based on port alarms are reduced in sequence, and the controller determines the target strategy to be the link discovery strategy based on the first clock protocol. In another embodiment, the first port and the second port both support the first clock protocol, the first discovery protocol, port traffic statistics, and port alarms, and the controller determines that the target strategy includes at least two of a link discovery strategy based on the first clock protocol, a link discovery strategy based on the first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms. In one example, the controller determines that the target strategy includes at least two of a link discovery strategy based on the first clock protocol, a link discovery strategy based on the first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms. In another example, the controller determines the target strategy in order (e.g., priority) to include a link discovery strategy based on the first clock protocol, a link discovery strategy based on the first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms. At least two of the following strategies: a link discovery strategy based on a first clock protocol, a link discovery strategy based on a first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms; for example, the priorities of a link discovery strategy based on a first clock protocol, a link discovery strategy based on a first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms are reduced in sequence, and the controller determines that the target strategy includes a link discovery strategy based on a first clock protocol and a link discovery strategy based on port traffic statistics. When the above four implementation methods are implemented in combination, the network device and the controller work together to discover cross-domain links based on at least two link discovery strategies during each link discovery process, which helps to improve the accuracy of discovering cross-domain links.

S703. The controller sends a target policy to the first network device and the second network device, where the target policy is used to instruct the first network device and the second network device to discover a cross-domain link between the first network domain and the second network domain based on the target policy.

The controller may send the target policy to the first network device and the second network device via NETCON or other private protocols. In one embodiment, the controller is a cross-domain controller, the cross-domain controller, the first controller, and the second controller are three independent controllers, the cross-domain controller sends the target policy to the first network device via the first controller, and the cross-domain controller sends the target policy to the second network device via the second controller. In another embodiment, the controller is a cross-domain controller, the cross-domain controller, the first controller, and the second controller are the same controller, the cross-domain controller directly sends the target policy to the first network device, and the cross-domain controller directly sends the target policy to the second network device.

In an optional embodiment, the controller sends indication information indicating a target policy to the first network device and the second network device (the indication information indicating a target policy is referred to as target policy information in this application). Depending on the target policy, the target policy information includes at least one of the following four implementations.

The first implementation method: the target policy includes a link discovery policy based on a first clock protocol, and the target policy information includes first policy information, and the first policy information is used to indicate the link discovery policy based on the first clock protocol. For example, the first policy information includes indication information of the first clock protocol, indication information of the first port of the first network device, and indication information of the second port of the second network device, and the first policy information is used to indicate the first network device to obtain link discovery information at the first port based on the first clock protocol, and to indicate the second network device to obtain link discovery information at the second port based on the first clock protocol.

The second implementation method: the target policy includes a link discovery policy based on the first discovery protocol, and the target policy information includes second policy information, and the second policy information is used to indicate the link discovery policy based on the first discovery protocol. For example, the second policy information includes indication information of the first discovery protocol, indication information of the first port of the first network device, and indication information of the second port of the second network device, and the second policy information is used to indicate the first network device to obtain link discovery information at the first port based on the first discovery protocol, and to indicate the second network device to obtain link discovery information at the second port based on the first discovery protocol.

A third implementation method: the target policy includes a link discovery policy based on port traffic statistics, and the target policy information includes third policy information, and the third policy information is used to indicate the link discovery policy based on port traffic statistics. For example, the third policy information includes port traffic statistics indication information, indication information of the first port of the first network device, and indication information of the second port of the second network device, and the port traffic statistics indication information is used to indicate that port traffic statistics are performed, and the third policy information is used to instruct the first network device to count the network traffic of the first port, and to instruct the second network device to count the network traffic of the second port. Optionally, the third policy information also includes indication information of the first time period to instruct the first network device and the second network device to count the network traffic of the corresponding network port within the first time period.

The fourth implementation method: the target policy includes a link discovery policy based on port alarms, and the target policy information includes fourth policy information, and the fourth policy information is used to indicate the link discovery policy based on port alarms. For example, the fourth policy information includes indication information of the first port of the first network device, indication information of the second port of the second network device, and disconnection indication information corresponding to the indication information of the first port, and the disconnection indication information is used to instruct the first network device to disconnect the first port (for example, disconnect the communication link corresponding to the first port), and the fourth policy information is used to instruct the first network device to disconnect the first port. Optionally, the fourth policy information also includes alarm monitoring indication information corresponding to the indication information of the second port, and the alarm monitoring indication information is used to instruct the second network device to monitor the alarm condition of the second port. The fourth policy information can also include indication information of the second time period to instruct the first network device to disconnect the first port within the second time period, and to instruct the second network device to monitor the alarm condition of the second port within the second time period.

It should be noted that the first time period and the second time period may be the same or different. The first time period and the second time period may overlap or not overlap, which is not limited in the embodiment of the present application.

To sum up, in the technical solution provided by the embodiment of the present application, the controller determines the target strategy (that is, the cross-domain link discovery strategy) based on the link discovery capability supported by the first port of the first network device in the first network domain and the link discovery capability supported by the second port of the second network device in the second network domain. Therefore, the process of determining the cross-domain link discovery strategy does not require human participation, does not require the staff to be familiar with the network situation, and has no additional requirements for the staff's skills.

In an optional embodiment, please refer to FIG8 , which shows a flowchart of another link discovery method provided by an embodiment of the present application. As shown, after S703, the method further includes the following steps S704 to S705.

S704. The controller obtains first discovery information and second discovery information, the first discovery information is the discovery information of the cross-domain link between the first network domain and the second network domain obtained by the first network device based on the target policy, and the second discovery information is the discovery information of the cross-domain link obtained by the second network device based on the target policy.

After the controller sends the target policy to the first network device and the second network device, the first network device obtains the discovery information of the cross-domain link between the first network domain and the second network domain based on the target policy (that is, the first discovery information), and the second network device obtains the discovery information of the cross-domain link between the first network domain and the second network domain based on the target policy (that is, the second discovery information), and the controller can obtain the first discovery information and the second discovery information. Optionally, the controller receives the first discovery information and the second discovery information, or the controller actively collects the first discovery information and the second discovery information. In one example, the controller is a cross-domain controller, and the first network device sends the first discovery information to the first controller after obtaining the first discovery information, and the first controller sends the first discovery information to the cross-domain controller after receiving the first discovery information, and the cross-domain controller receives the first discovery information sent by the first controller; similarly, the second network device sends the second discovery information to the second controller after obtaining the second discovery information, and the second controller sends the second discovery information to the cross-domain controller after receiving the second discovery information, and the cross-domain controller receives the second discovery information sent by the second controller. In another example, the controller is a cross-domain controller. After the first network device obtains the first discovery information, the first controller collects the first discovery information from the first network device and sends the first discovery information to the cross-domain controller, and the cross-domain controller receives the first discovery information sent by the first controller. Similarly, after the second network device obtains the second discovery information, the second controller collects the second discovery information from the second network device and sends the second discovery information to the cross-domain controller, and the cross-domain controller receives the second discovery information sent by the second controller. The first network device sends the first discovery information to the first controller via BGP, NETCONF, PCEP, telemetry protocol, Qx protocol or other private protocols; and/or the second network device sends the second discovery information to the second controller via BGP, NETCONF, PCEP, telemetry protocol, Qx protocol or other private protocols, which is not limited in this application.

In an optional embodiment, in S703, the controller sends target policy information to the first network device and the second network device. After receiving the target policy information, the first network device determines the target policy according to the target policy information, and then the first network device obtains the discovery information of the cross-domain link between the first network domain and the second network domain based on the target policy. Similarly, after receiving the target policy information, the second network device determines the target policy according to the target policy information, and then the second network device obtains the discovery information of the cross-domain link between the first network domain and the second network domain based on the target policy. Depending on the target policy and the target policy information, the implementation method of the first network device and the second network device obtaining the link discovery information is different. For example, the first network device and the second network device obtain the link discovery information including at least one of the following four implementation methods.

The first implementation method: the target policy information includes first policy information, the first policy information is used to indicate a link discovery strategy based on a first clock protocol, the target policy includes a link discovery strategy based on the first clock protocol, and the first network device and the second network device respectively obtain link discovery information based on the link discovery strategy of the first clock protocol.

The first network device and the second network device respectively determine that the target policy includes a link discovery policy based on the first clock protocol according to the first policy information included in the target policy information. The first network device obtains the first discovery information based on the first clock protocol message during the transmission (e.g., sending or receiving) of the first clock protocol message. The second network device obtains the second discovery information based on the first clock protocol message during the transmission (e.g., sending or receiving) of the first clock protocol message.

Optionally, the first policy information includes indication information of the first clock protocol, indication information of the first port of the first network device, and indication information of the second port of the second network device. The first network device determines the first clock protocol according to the indication information of the first clock protocol, the first network device determines the first port of the first network device according to the indication information of the first port, and the first network device obtains the first discovery information based on the first clock protocol message during the process of transmitting (e.g., sending or receiving) the first clock protocol message through the first port. Similarly, the second network device determines the first clock protocol according to the indication information of the first clock protocol, the second network device determines the second port of the second network device according to the indication information of the second port, and the second network device obtains the second discovery information based on the first clock protocol message during the process of transmitting (e.g., sending or receiving) the first clock protocol message through the second port. Among them, the first discovery information includes the indication information of the first port, the second discovery information includes the indication information of the second port, and at least one of the first discovery information and the second discovery information includes the corresponding relationship between the first port and the second port. In one example, the second network device is the next-hop device of the first network device. The first network device sends a first clock protocol message to the second network device through a first port. The first clock protocol message carries indication information of the first port. The second network device receives the first clock protocol message through a second port. The second network device obtains the correspondence between the first port and the second port based on the network port (i.e., the second port) at which the second network device receives the first clock protocol message and the indication information of the first port carried by the first clock protocol message. Then, the second discovery information includes the correspondence between the first port and the second port. In another example, the first network device is the next-hop device of the second network device. The second network device sends a first clock protocol message to the first network device through a second port. The first clock protocol message carries indication information of the second port. The first network device receives the first clock protocol message through the first port. The network device obtains the correspondence between the first port and the second port according to the network port (i.e., the first port) through which the first network device receives the first clock protocol message and the indication information of the second port carried by the first clock protocol message, and the first discovery information includes the correspondence between the first port and the second port.

The second implementation method: the target policy information includes second policy information, the second policy information is used to indicate a link discovery strategy based on the first discovery protocol, the target policy includes a link discovery strategy based on the first discovery protocol, and the first network device and the second network device respectively obtain link discovery information based on the link discovery strategy of the first discovery protocol.

The first network device and the second network device respectively determine that the target policy includes a link discovery policy based on the first discovery protocol according to the second policy information included in the target policy information. The first network device obtains the first discovery information based on the first discovery protocol message during the process of transmitting (e.g., sending or receiving) the first discovery protocol message. The second network device obtains the second discovery information based on the first discovery protocol message during the process of transmitting (e.g., sending or receiving) the first discovery protocol message.

Optionally, the second policy information includes indication information of the first discovery protocol, indication information of the first port of the first network device, and indication information of the second port of the second network device. The first network device determines the first discovery protocol according to the indication information of the first discovery protocol, the first network device determines the first port of the first network device according to the indication information of the first port, and the first network device obtains the first discovery information based on the first discovery protocol message during the process of transmitting (e.g., sending or receiving) the first discovery protocol message through the first port. Similarly, the second network device determines the first discovery protocol according to the indication information of the first discovery protocol, the second network device determines the second port of the second network device according to the indication information of the second port, and the second network device obtains the second discovery information based on the first discovery protocol message during the process of transmitting (e.g., sending or receiving) the first discovery protocol message through the second port. Among them, the first discovery information includes the indication information of the first port, the second discovery information includes the indication information of the second port, and at least one of the first discovery information and the second discovery information includes the corresponding relationship between the first port and the second port. In one example, the second network device is the next hop device of the first network device, the first network device sends a first discovery protocol message to the second network device through the first port, the first discovery protocol message carries the indication information of the first port, the second network device receives the first discovery protocol message through the second port, the second network device obtains the correspondence between the first port and the second port according to the network port (i.e., the second port) at which the second network device receives the first discovery protocol message and the indication information of the first port carried by the first discovery protocol message, then the second discovery information includes the correspondence between the first port and the second port. In another example, the first network device is the next hop device of the second network device, the second network device sends a first discovery protocol message to the first network device through the second port, the first discovery protocol message carries the indication information of the second port, the first network device receives the first discovery protocol message through the first port, the first network device obtains the correspondence between the first port and the second port according to the network port (i.e., the first port) at which the first network device receives the first discovery protocol message and the indication information of the second port carried by the first discovery protocol message, then the first discovery information includes the correspondence between the first port and the second port.

The third implementation method: the target policy information includes third policy information, the third policy information is used to indicate a link discovery strategy based on port traffic statistics, the target policy includes a link discovery strategy based on port traffic statistics, and the first network device and the second network device respectively obtain link discovery information based on the link discovery strategy based on port traffic statistics.

Optionally, the third policy information includes port traffic statistics indication information, indication information of the first port of the first network device, indication information of the second port of the second network device, and indication information of the first time period. The first network device determines that port traffic statistics need to be performed according to the port traffic statistics indication information, the first network device determines the first port of the first network device according to the indication information of the first port, and the first network device determines the first time period according to the indication information of the first time period, and then the first network device determines that the network traffic of the first port in the first time period needs to be counted. The first network device starts counting the network traffic of the first port from the start time of the first time period, and ends counting the network traffic of the first port at the end time of the first time period, and the first network device obtains the first discovery information based on the statistical result. Among them, the first discovery information includes the indication information of the first port and the traffic distribution curve of the first port in the first time period, and the traffic distribution curve of the first port in the first time period is used to characterize the traffic distribution of the first port in the first time period. Similarly, the second network device determines that the network traffic of the second port in the first time period needs to be counted according to the third policy information, the second network device starts counting the network traffic of the second port from the start time of the first time period, and ends counting the network traffic of the second port at the end time of the first time period, and the second network device obtains the second discovery information based on the statistical result. The second discovery information includes indication information of the second port and a traffic distribution curve of the second port in the first time period, and the traffic distribution curve of the second port in the first time period is used to characterize traffic distribution of the second port in the first time period.

The fourth implementation method: the target policy information includes fourth policy information, the fourth policy information is used to indicate a link discovery strategy based on port alarms, the target policy includes a link discovery strategy based on port alarms, and the first network device and the second network device respectively obtain link discovery information based on the link discovery strategy based on port alarms.

Optionally, the fourth policy information includes the indication information of the first port of the first network device and the indication information of the second port of the second network device. Information, disconnection indication information corresponding to the indication information of the first port, alarm monitoring indication information corresponding to the indication information of the second port, and indication information of the second time period. The first network device determines the first port of the first network device according to the indication information of the first port, the first network device determines to disconnect the first port according to the disconnection indication information corresponding to the indication information of the first port, and the first network device determines the second time period according to the indication information of the second time period, and then the first network device determines that the first port needs to be disconnected within the second time period; the first network device controls the first port to be disconnected within the second time period (for example, the first network device turns off the laser of the first port at the start time of the second time period, and turns on the laser of the first port at the end time of the second time period, thereby controlling the first port to be in a disconnected state within the second time period), and the first network device obtains the first discovery information at the end of the second time period. Wherein, the first discovery information includes the indication information of the first port and the disconnection time information, and the disconnection time information is used to indicate that the first port is disconnected within the second time period, for example, the disconnection time information is used to indicate that the first port is disconnected within the second time period and the duration of the first port being in a disconnected state is equal to the duration of the second time period. The second network device determines the second port of the second network device according to the indication information of the second port, the second network device determines the alarm situation of the second port that needs to be monitored according to the alarm monitoring indication information corresponding to the indication information of the second port, and the second network device determines the second time period according to the indication information of the second time period, and then the second network device determines the alarm situation of the second port in the second time period that needs to be monitored. The second network device starts to monitor the alarm situation of the second port from the start time of the second time period, and stops monitoring the alarm situation of the second port at the end time of the second time period, and the second network device obtains the second discovery information according to the monitoring result. Among them, the second discovery information includes the indication information and alarm time information of the second port, and the alarm time information is used to indicate the time period when the second port generates an alarm. The time period when the second port generates an alarm may be the second time period or may not be the second time period. This application takes the time period when the second port generates an alarm as the second time period as an example, then the alarm time information is used to indicate that the second port generates an alarm in the second time period, for example, the alarm time information is used to indicate that the second port generates an alarm in the second time period and the duration of the alarm generation of the second port is equal to the duration of the second time period.

S705. The controller determines a cross-domain link between the first network domain and the second network domain according to the first discovery information and the second discovery information.

The controller may determine a communication link between a first port of the first network device and a second port of the second network device according to the first discovery information and the second discovery information, and the communication link is a cross-domain link between the first network domain and the second network domain.

In an embodiment of the present application, according to different target discovery strategies, the content of the first discovery information is different, the content of the second discovery information is different, and the controller determines the implementation method of the cross-domain link between the first network domain and the second network domain according to the first discovery information and the second discovery information in different ways. For example, S705 includes at least one of the following four implementation methods.

The first implementation method: the target strategy includes a link discovery strategy based on the first clock protocol, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, and at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port. The controller determines the first port of the first network device according to the indication information of the first port included in the first discovery information, the controller determines the second port of the second network device according to the indication information of the second port included in the second discovery information, and the controller determines that the first port corresponds to the second port according to the correspondence between the first port and the second port included in the first discovery information and/or the second discovery information. The controller determines that the first port corresponds to the second port, that is, the controller determines that there is a cross-domain link between the first port and the second port.

The second implementation method: the target strategy includes a link discovery strategy based on the first discovery protocol, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, and at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port. The controller determines the first port of the first network device according to the indication information of the first port included in the first discovery information, the controller determines the second port of the second network device according to the indication information of the second port included in the second discovery information, and the controller determines that the first port corresponds to the second port according to the correspondence between the first port and the second port included in the first discovery information and/or the second discovery information. The controller determines that the first port corresponds to the second port, that is, the controller determines that there is a cross-domain link between the first port and the second port.

A third implementation method: the target strategy includes a link discovery strategy based on port traffic statistics, the first discovery information includes indication information of the first port and a traffic distribution curve of the first port in a first time period, and the second discovery information includes indication information of the second port and a traffic distribution curve of the second port in the first time period. The controller determines the first port of the first network device according to the indication information of the first port included in the first discovery information, determines the second port of the second network device according to the indication information of the second port included in the second discovery information, and determines that the first port corresponds to the second port according to the traffic distribution curve of the first port in the first time period included in the first discovery information and the traffic distribution curve of the second port in the first time period included in the second discovery information, so that the controller determines that there is a cross-domain link between the first port and the second port. For example, the controller determines that the traffic distribution curve of the first port in the first time period matches the traffic distribution curve of the second port in the first time period, for example, the traffic distribution curve of the first port in the first time period is the same as the traffic distribution curve of the second port in the first time period and the two overlap in the same coordinate system, so that the controller determines that the first port corresponds to the second port.

Fourth implementation: the target strategy includes a link discovery strategy based on port alarms, the first discovery information includes indication information and disconnection time information of the first port, the disconnection time information is used to indicate that the first port is disconnected within the second time period, and the second discovery information includes indication information and alarm time information of the second port, the alarm time information is used to indicate that the second port has an alarm within the second time period. The controller determines the first port of the first network device according to the indication information of the first port included in the first discovery information, the controller determines the second port of the second network device according to the indication information of the second port included in the second discovery information, and the controller determines that the first port of the first network device corresponds to the second port of the second network device according to the disconnection time information included in the first discovery information and the alarm time information included in the second discovery information, so that the controller determines that there is a cross-domain link between the first port and the second port. For example, the controller determines that the first port is disconnected within the second time period and the duration of the first port being in the disconnected state is equal to the duration of the second time period according to the disconnection time information, and the controller determines that the second port has an alarm within the second time period and the duration of the second port having an alarm is equal to the duration of the second time period according to the alarm time information, so that the controller determines that the first port corresponds to the second port.

Optionally, the first discovery information also includes indication information of the first network device, and the second discovery information also includes indication information of the second network device. In the above four implementation methods, the controller also determines the first network device based on the indication information of the first network device, and the controller also determines the second network device based on the indication information of the second network device. The controller determines that the first port belongs to the first network device based on the first discovery information, and determines that the second port belongs to the second network device based on the second discovery information, so that the controller determines that there is a cross-domain link between the first port of the first network device and the second port of the second network device.

In summary, the technical solution provided by the embodiment of the present application is that the controller determines the target strategy (i.e., the discovery strategy of the cross-domain link) according to the link discovery capability supported by the first port of the first network device in the first network domain and the link discovery capability supported by the second port of the second network device in the second network domain, and the first network device and the second network device obtain link discovery information according to the target strategy, and then the controller determines the cross-domain link according to the link discovery information obtained by the first network device and the second network device. That is, the controller determines the discovery strategy of the cross-domain link according to the link discovery capability supported by the network ports of network devices in different network domains, the network device obtains link discovery information according to the discovery strategy of the cross-domain link determined by the controller, and the controller determines the cross-domain link according to the link discovery information obtained by the network device, thereby, the process of determining the discovery strategy of the cross-domain link and the process of discovering the cross-domain link based on the discovery strategy do not require manual participation, the staff does not need to be familiar with the network situation, there is no additional requirement for the skills of the staff, and the accuracy of the determined cross-domain link is high.

The technical solution provided by the embodiment of the present application is that the controller flexibly selects the link discovery strategy to discover the cross-domain link according to the link discovery capability supported by the network port. The link discovery strategy that the controller can select includes a link discovery strategy based on the first clock protocol. In this link discovery strategy, the network device can obtain link discovery information according to the first clock protocol deployed in the existing network, and can discover the cross-domain link without additional configuration. The operation process is simple and the accuracy of discovering the cross-domain link is high, and the application scenarios are wide. For example, 90% of the network devices in the existing network support the clock protocol. Therefore, the link discovery solution provided by this application can be applied to most network scenarios. The application scenarios of this link discovery solution are wide and the universality is strong. The link discovery strategy that the controller can select also includes a link discovery strategy based on the first discovery protocol, a link discovery strategy based on port traffic statistics, and a link discovery strategy based on port alarms. These three link discovery strategies can be used at least for the remaining 10% of network devices to discover cross-domain links. In this way, the technical solution of this application can support various network scenarios.

Please refer to Figure 9, which shows an interaction diagram of another link discovery method provided by an embodiment of the present application. As shown in Figure 9, the method includes the following steps S901 to S915.

S901. A first network device sends first capability information to a first controller, where the first capability information is used to indicate a link discovery capability supported by a first port of the first network device.

The first network device is in the first network domain, and the first controller is the controller of the first network domain. The link discovery capability supported by the first port includes at least one of the following: a first clock protocol, a first discovery protocol, port traffic statistics, and a port alarm.

S902. The first controller sends first capability information to the cross-domain controller.

S903. The second network device sends second capability information to the second controller, where the second capability information is used to indicate a link discovery capability supported by a second port of the second network device.

The second network device is in the second network domain, and the second controller is a controller of the second network domain. The network type of the first network domain is different from the network type of the second network domain. For example, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain. The link discovery capability supported by the second port includes at least one of the following: a first clock protocol, a first discovery protocol, port traffic statistics, and a port alarm.

S904. The second controller sends second capability information to the cross-domain controller.

S905. The cross-domain controller determines a target policy based on the first capability information and the second capability information, where the target policy is used to indicate A cross-domain link between a first network domain and a second network domain is discovered.

S906. The cross-domain controller sends the target policy to the first controller and the second controller respectively.

S907. The first controller sends the target policy to the first network device.

S908. The second controller sends the target policy to the second network device.

S909. The first network device obtains first discovery information based on the target policy.

The first discovery information is discovery information of a cross-domain link between the first network domain and the second network domain.

S910. The first network device sends first discovery information to the first controller.

S911. The first controller sends first discovery information to the cross-domain controller.

S912. The second network device obtains second discovery information based on the target policy.

The second discovery information is discovery information of a cross-domain link between the first network domain and the second network domain.

S913. The second network device sends second discovery information to the second controller.

S914. The second controller sends second discovery information to the cross-domain controller.

S915. The cross-domain controller determines a cross-domain link between the first port and the second port according to the first discovery information and the second discovery information.

The detailed implementation process of the above S901 to S915 can refer to the embodiments shown in Figures 7 and 8, and will not be repeated here.

It should be noted that, in the embodiment of the present application, a certain network port supports a certain link discovery capability, which means that the certain network port supports the certain link discovery capability from the hardware, and the certain network port enables the certain link discovery capability before executing the link discovery scheme of the present application. For example, the first port supports the link discovery capability based on the first clock protocol, which means that the first port supports the first clock protocol from the hardware, and the first port enables the link discovery capability based on the first clock protocol before executing the link discovery scheme of the present application. Optionally, if a certain network port supports a certain link discovery capability from the hardware, but the certain network port does not enable the certain link discovery capability before executing the link discovery scheme of the present application, the present application also supports the controller controlling a certain network port to enable the certain link discovery capability. For example, the controller sends an enabling information to the network device where the certain network port is located, and the network device enables the certain link discovery capability of the certain network port according to the enabling information. For example, the controller is a cross-domain controller, the network device where the certain network port is located is located in the first network domain, and the cross-domain controller sends enabling information to the network device where the certain network port is located through the first controller. In addition, the present application also supports the cross-domain controller, the first controller and the second controller to collaboratively perform network configuration. For example, the first controller collects information about the first network domain and sends the information about the first network domain to the cross-domain controller. The cross-domain controller sends a configuration command to the first controller based on the information about the first network domain, and the first controller configures the first network domain according to the configuration command sent by the cross-domain controller. Similarly, the second controller collects information about the second network domain and sends the information about the second network domain to the cross-domain controller. The cross-domain controller sends a configuration command to the second controller based on the information about the second network domain, and the second controller configures the second network domain according to the configuration command sent by the cross-domain controller.

The above is an introduction to the method embodiment of the present application. The following is an introduction to the device embodiment of the present application, which can be used to execute the method of the present application. For details not disclosed in the device embodiment, please refer to the method embodiment.

Please refer to FIG. 10 , which shows a schematic diagram of a link discovery device 1000 provided in an embodiment of the present application. The link discovery device 1000 is applied to a controller. For example, the link discovery device 1000 is a controller or a functional component in the controller. Referring to FIG. 10 , the link discovery device 1000 includes an acquisition module 1010 and a determination module 1020 .

The acquisition module 1010 is used to acquire first discovery information and second discovery information, wherein the first discovery information is discovery information of a first link acquired by a first network device based on a clock protocol message, and the second discovery information is discovery information of a first link acquired by a second network device based on the clock protocol message, wherein the first network device is in a first network domain, and the second network device is in a second network domain, and the network type of the first network domain is different from the network type of the second network domain, and the first link is a cross-domain link between a first port of the first network device and a second port of the second network device. The functional implementation of the acquisition module 1010 may refer to the relevant description in the above S301.

The determination module 1020 is configured to determine the first link according to the first discovery information and the second discovery information. The implementation of the function of the determination module 1020 may refer to the relevant description in the above S302.

Optionally, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, and at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port. The determination module 1020 is used to: determine the first port of the first network device according to the indication information of the first port; determine the second port of the second network device according to the indication information of the second port; and determine that the first port corresponds to the second port according to the correspondence.

Optionally, the first discovery information further includes indication information of the first network device, and the second discovery information further includes indication information of the second network device. The determining module 1020 is further configured to: determine the first network device according to the indication information of the first network device;

The second network device is determined according to the indication information of the second network device.

Optionally, please continue to refer to Figure 10, the link discovery device 1000 also includes: a sending module 1030, which is used to send a target policy to the first network device and the second network device before the acquisition module 1010 acquires the first discovery information and the second discovery information, and the target policy is used to instruct the first network device and the second network device to discover the cross-domain link between the first network domain and the second network domain based on the first clock protocol, and the above-mentioned clock protocol message is a message based on the first clock protocol. The functional implementation of the sending module 1030 can refer to the relevant description in the above S303.

Optionally, the acquisition module 1010 is further used to acquire first capability information and second capability information before the sending module 1030 sends the target policy to the first network device and the second network device, the first capability information being used to indicate that the first port supports the first clock protocol, and the second capability information being used to indicate that the second port supports the first clock protocol. The functional implementation of the acquisition module 1010 may refer to the relevant description in the above S304.

The determination module 1020 is further configured to determine a target policy according to the first capability information and the second capability information. The implementation of the function of the determination module 1020 may refer to the relevant description in the above S305.

Optionally, the controller is a cross-domain controller, and the acquisition module 1010 is used to: receive first discovery information sent by a first controller, where the first controller is a controller of a first network domain; and receive second discovery information sent by a second controller, where the second controller is a controller of a second network domain.

Optionally, the cross-domain controller, the first controller and the second controller are three different controllers.

Optionally, at least two of the cross-domain controller, the first controller, and the second controller are one controller. For example, the cross-domain controller is one controller, and the first controller and the second controller are the same controller; or, the cross-domain controller, the first controller, and the second controller are one controller.

Optionally, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain.

Optionally, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain.

In summary, the technical solution provided by the embodiment of the present application is that the first network device in the first network domain and the second network device in the second network domain obtain link discovery information based on the clock protocol message, and the controller determines the cross-domain link between the first port of the first network device and the second port of the second network device according to the link discovery information obtained by the first network device and the second network device. That is, in the embodiment of the present application, the controller and the network device work together to discover the cross-domain link based on the clock protocol message. Since most network devices support the clock protocol, the link discovery solution provided by the embodiment of the present application can be applied to most network scenarios, and the link discovery solution has a wide range of application scenarios and strong universality.

Please refer to FIG. 11 , which shows a schematic diagram of another link discovery device 1100 provided in an embodiment of the present application. The link discovery device 1100 is applied to a controller. For example, the link discovery device 1100 is a controller or a functional component in the controller. Referring to FIG. 11 , the link discovery device 1100 includes an acquisition module 1110 and a sending module 1120.

The acquisition module 1110 is used to acquire first capability information and second capability information, wherein the first capability information is used to indicate a link discovery capability supported by a first port of a first network device, and the second capability information is used to indicate a link discovery capability supported by a second port of a second network device, wherein the first network device is in a first network domain, and the second network device is in a second network domain, and a network type of the first network domain is different from a network type of the second network domain. The functional implementation of the acquisition module 1110 may refer to the relevant description in the above S701.

The sending module 1120 is used to send a target policy to the first network device and the second network device, where the target policy is used to instruct the first network device and the second network device to discover a cross-domain link between the first network domain and the second network domain based on the target policy, where the target policy is determined according to the first capability information and the second capability information. The functional implementation of the sending module 1120 can refer to the relevant description in S703 above.

Optionally, the target strategy includes at least one of the following: a link discovery strategy based on a first clock protocol; a link discovery strategy based on a first discovery protocol; a link discovery strategy based on port traffic statistics; a link discovery strategy based on port alarms.

Optionally, please continue to refer to Figure 11, the link discovery device 1100 also includes: a determination module 1130, which is used to determine the target policy according to the first capability information and the second capability information before the sending module 1120 sends the target policy to the first network device and the second network device. The functional implementation of the determination module 1130 can refer to the relevant description in the above S702.

Optionally, the determination module 1130 is configured to:

When the first capability information is used to indicate that the first port supports a link discovery capability based on a first clock protocol and the second capability information is used to indicate that the second port supports a link discovery capability based on the first clock protocol, determining that the target strategy includes a link discovery strategy based on the first clock protocol; and/or,

When the first capability information is used to indicate that the first port supports a link discovery capability based on a first discovery protocol and the second capability information is used to indicate that the second port supports a link discovery capability based on the first discovery protocol, determining that the target policy includes a link discovery policy based on the first discovery protocol; and / or,

When the first capability information is used to indicate that the first port supports a link discovery capability based on port traffic statistics and the second capability information is used to indicate that the second port supports a link discovery capability based on port traffic statistics, the device determines that the target strategy includes a link discovery strategy based on port traffic statistics; and/or,

When the first capability information is used to indicate that the first port supports a link discovery capability based on port alarms and the second capability information is used to indicate that the second port supports a link discovery capability based on port alarms, it is determined that the target policy includes a link discovery policy based on port alarms.

Optionally, the acquisition module 1110 is further used to acquire first discovery information and second discovery information after the sending module 1120 sends the target policy to the first network device and the second network device, the first discovery information being the discovery information of the cross-domain link between the first network domain and the second network domain acquired by the first network device based on the target policy, and the second discovery information being the discovery information of the cross-domain link acquired by the second network device based on the target policy. The functional implementation of the acquisition module 1110 may refer to the relevant description in S704 above.

The determination module 1130 is further configured to determine the cross-domain link according to the first discovery information and the second discovery information. The implementation of the function of the determination module 1130 may refer to the relevant description in the above S705.

Optionally, the target strategy includes a link discovery strategy based on a first clock protocol, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port, and the determination module 1130 is used to: determine the first port of the first network device according to the indication information of the first port; determine the second port of the second network device according to the indication information of the second port; and determine that the first port corresponds to the second port according to the correspondence.

Optionally, the target strategy includes a link discovery strategy based on a first discovery protocol, the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port, and the determination module 1130 is used to: determine the first port of the first network device according to the indication information of the first port; determine the second port of the second network device according to the indication information of the second port; and determine that the first port corresponds to the second port according to the correspondence.

Optionally, the target strategy includes a link discovery strategy based on port traffic statistics, the first discovery information includes indication information of the first port and a traffic distribution curve of the first port in a first time period, the second discovery information includes indication information of the second port and a traffic distribution curve of the second port in the first time period, and the determination module 1130 is used to: determine the first port of the first network device according to the indication information of the first port; determine the second port of the second network device according to the indication information of the second port; determine the correspondence between the first port and the second port according to the traffic distribution curve of the first port in the first time period and the traffic distribution curve of the second port in the first time period.

Optionally, the target strategy includes a link discovery strategy based on port alarms, the first discovery information includes indication information and disconnection time information of the first port, the disconnection time information is used to indicate that the first port is disconnected within a second time period, the second discovery information includes indication information and alarm time information of the second port, the alarm time information is used to indicate that an alarm occurs on the second port within the second time period, and the determination module 1130 is used to: determine the first port of the first network device according to the indication information of the first port; determine the second port of the second network device according to the indication information of the second port; and determine that the first port corresponds to the second port according to the disconnection time information and the alarm time information.

Optionally, the first discovery information further includes indication information of the first network device, and the second discovery information further includes indication information of the second network device. The determination module 1130 is further configured to: determine the first network device according to the indication information of the first network device;

The second network device is determined according to the indication information of the second network device.

Optionally, the controller is a cross-domain controller, and the acquisition module 1110 is used to:

receiving first capability information sent by a first controller, where the first controller is a controller of a first network domain;

Second capability information sent by a second controller is received, where the second controller is a controller of a second network domain.

Optionally, the cross-domain controller, the first controller and the second controller are three different controllers.

Optionally, at least two of the cross-domain controller, the first controller, and the second controller are one controller. For example, the cross-domain controller is one controller, and the first controller and the second controller are the same controller; or, the cross-domain controller, the first controller, and the second controller are one controller.

Optionally, one of the first network domain and the second network domain is an optical network domain, and the other network domain is an IP network domain.

Optionally, one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain.

In summary, the technical solution provided by the embodiment of the present application is that the controller determines the target strategy (i.e., the cross-domain link discovery strategy) according to the link discovery capabilities supported by the network ports of network devices in different network domains. The process of determining the cross-domain link discovery strategy does not require manual participation, does not require the staff to be familiar with the network situation, and does not require additional skills for the staff. The network device obtains the link discovery strategy according to the target strategy determined by the controller. The controller determines the cross-domain link based on the link discovery information obtained by the network device. The process of determining the cross-domain link does not require manual participation and has no additional requirements on the skills of the staff.

The link discovery device provided in the embodiment of the present application can also be implemented using an application-specific integrated circuit (ASIC) or a programmable logic device (PLD). The above-mentioned PLD can be a complex programmable logical device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. The method provided in the above-mentioned method embodiment can also be implemented by software. When the method provided in the above-mentioned method embodiment is implemented by software, each module in the above-mentioned link discovery device can also be a software module.

An embodiment of the present application provides a link discovery device, including a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program stored in the memory so that the link discovery device performs all or part of the steps of the link discovery method provided by the above method embodiment.

For example, please refer to Figure 12, which shows a schematic diagram of a link discovery device 1200 provided in an embodiment of the present application. The link discovery device 1200 is a controller or a functional component in the controller. The link discovery device 1200 includes a processor 1201, a memory 1202, a bus 1203, a network interface 1204, and an input-output device 1205. The processor 1201, the memory 1202, the network interface 1204, and the input-output device 1205 are connected via the bus 1203. Figure 12 illustrates that the processor 1201 and the memory 1202 are independent of each other. The processor 1201 and the memory 1202 can also be integrated together.

The memory 1202 is used to store computer programs, which include operating systems and program codes. The memory 1202 is a storage medium of various types, such as random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), flash memory, register, optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), disk or other magnetic storage device.

Processor 1201 is a general-purpose processor or a special-purpose processor. A general-purpose processor is a processor that performs specific steps and/or operations by reading and executing a computer program stored in a memory. The general-purpose processor may use a computer program stored in a memory in the process of performing the above steps and/or operations. The computer program is executed, for example, to implement the related functions of the aforementioned acquisition module and determination module. A general-purpose processor is, for example, but not limited to, a central processing unit (CPU). A special-purpose processor is a processor specially designed to perform specific steps and/or operations. A special-purpose processor is, for example, but not limited to, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a complex programmable logical device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. Processor 1201 may be a single-CPU processor or a multi-CPU processor. The processor 1201 includes at least one circuit to execute all or part of the steps of the link discovery method provided in the above embodiment.

The network interface 1204 is used for the link discovery device 1200 to communicate with other devices. The network interface 1204 includes a physical interface and a logical interface. The physical interface may be a gigabit Ethernet interface (GE), which is used to interconnect the link discovery device 1200 with other devices, and the logical interface may be an interface inside the link discovery device 1200, which is used to interconnect the devices inside the link discovery device 1200. It is easy to understand that the network interface 1204 can be used for the link discovery device 1200 to communicate with other devices, for example, the network interface 1204 is used to send and receive information between the link discovery device 1200 and other devices, and the network interface 1204 can implement the related functions of the aforementioned sending module.

The input/output device 1205 includes an input/output (I/O) interface, devices such as a keyboard, a mouse, and a display connected to the link discovery device 1200 through the I/O interface, and devices such as a display connected to the processor 1201 through a bus. The processor 1201 can receive input commands or data through the input/output device 1205 and output processed data. For example, the input/output device 1205 includes a display, which can be used to display intermediate results and/or final results generated by the processor 1201 executing the above-mentioned link discovery method.

The bus 1203 is any type of communication bus used to interconnect the internal components of the link discovery device 1200. The embodiment of the present application takes the above-mentioned devices in the link discovery device 1200 being interconnected through the bus 1203 as an example, and the above-mentioned devices in the link discovery device 1200 are connected to each other using other connection methods, for example, the above-mentioned devices in the link discovery device 1200 are interconnected through a logical interface inside the link discovery device 1200.

The above devices may be arranged on independent chips, or at least partially or completely on the same chip. Whether to arrange each device independently on different chips or to integrate them on one or more chips often depends on the needs of product design. The embodiments of the present application do not limit the specific implementation form of the above devices.

The link discovery device 1200 shown in FIG12 is merely exemplary, and the link discovery device 1200 may also include other components, which are not listed here. The link discovery device 1200 shown in FIG12 can discover cross-domain links between different types of network domains by executing all or part of the steps of the link discovery method provided in the above embodiment.

The embodiment of the present application provides a link discovery system, including a controller, a first network device, and a second network device. The first network device is in a first network domain, the second network device is in a second network domain, and the network type of the first network domain is different from the network type of the second network domain. The controller includes a link discovery device as shown in any one of Figures 10 to 12.

Optionally, the controller is a cross-domain controller, and the link discovery system further includes a first controller and a second controller, the first controller is a controller of a first network domain, and the second controller is a controller of a second network domain.

Optionally, the cross-domain controller, the first controller and the second controller may be three different controllers.

Optionally, at least two of the cross-domain controller, the first controller, and the second controller are one controller. For example, the cross-domain controller is one controller, and the first controller and the second controller are the same controller; or, the cross-domain controller, the first controller, and the second controller are one controller.

Optionally, one of the first network domain and the second network domain is an optical network domain, and the other is an IP network domain.

Optionally, one of the first network domain and the second network domain is a wireless network domain, and the other is a wired network domain.

Illustratively, the link discovery system is a communication network as shown in FIG. 1 or FIG. 2 .

An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed (for example, executed by a controller, one or more processors, etc.), all or part of the steps of the link discovery method provided in the above method embodiment are implemented.

An embodiment of the present application provides a computer program product, which includes a program or code. When the program or code is executed (for example, executed by a controller, one or more processors, etc.), it implements all or part of the steps of the link discovery method provided in the above method embodiment.

An embodiment of the present application provides a chip, which includes a programmable logic circuit and/or program instructions, and when the chip is running, it is used to implement all or part of the steps of the link discovery method provided in the above method embodiment.

In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product, and the computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server, a data center, etc. that contains one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium, or a semiconductor medium (e.g., a solid-state hard disk), etc.

It should be understood that the term "at least one" in this application refers to one or more, and "plurality" refers to two or more. The term "and/or" in this application is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, for the sake of clarity of description, in this application, words such as "first", "second", and "third" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first", "second", and "third" do not distinguish between quantity and execution. The order of the rows is limited.

The different types of embodiments such as the method embodiments and device embodiments provided in the embodiments of the present application can refer to each other, and the embodiments of the present application are not limited thereto. The sequence of operations of the method embodiments provided in the embodiments of the present application can be appropriately adjusted, and the operations can also be increased or decreased in response to the situation. Any technician familiar with the technical field can easily think of the changed methods within the technical scope disclosed in the present application, and they should be included in the protection scope of the present application, so they will not be repeated.

In the corresponding embodiments provided in the present application, it should be understood that the disclosed devices and the like can be implemented by other configuration methods. For example, the device embodiments described above are only illustrative, for example, the division of modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

The modules described as separate components may or may not be physically separated, and the components described as modules may or may not be physical modules, and may be located in one place or distributed on multiple devices. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above is only an exemplary embodiment of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims (29)

A link discovery method, characterized in that the method comprises: The controller obtains first discovery information and second discovery information, wherein the first discovery information is discovery information of a first link obtained by a first network device based on a clock protocol message, and the second discovery information is discovery information of the first link obtained by a second network device based on the clock protocol message, the first network device is in a first network domain, the second network device is in a second network domain, a network type of the first network domain is different from a network type of the second network domain, and the first link is a cross-domain link between a first port of the first network device and a second port of the second network device; The controller determines the first link according to the first discovery information and the second discovery information. The method according to claim 1, wherein the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a correspondence between the first port and the second port, and the controller determines the first link according to the first discovery information and the second discovery information, comprising: The controller determines the first port of the first network device according to the indication information of the first port; The controller determines the second port of the second network device according to the indication information of the second port; The controller determines, according to the corresponding relationship, that the first port corresponds to the second port. The method according to claim 2 is characterized in that the first discovery information further includes indication information of the first network device, the second discovery information further includes indication information of the second network device, and the controller determines the first link according to the first discovery information and the second discovery information, further comprising: The controller determines the first network device according to the indication information of the first network device; The controller determines the second network device according to the indication information of the second network device. The method according to any one of claims 1 to 3, characterized in that before the controller obtains the first discovery information and the second discovery information, the method further comprises: The controller sends a target policy to the first network device and the second network device, where the target policy is used to instruct the first network device and the second network device to discover the cross-domain link between the first network domain and the second network domain based on a first clock protocol, and the clock protocol message is a message based on the first clock protocol. The method according to claim 4, characterized in that before the controller sends the target policy to the first network device and the second network device, the method further comprises: The controller acquires first capability information and second capability information, the first capability information being used to indicate that the first port supports the first clock protocol, and the second capability information being used to indicate that the second port supports the first clock protocol; The controller determines the target policy according to the first capability information and the second capability information. The method according to any one of claims 1 to 5, characterized in that the controller is a cross-domain controller, and the controller obtains the first discovery information and the second discovery information, comprising: The controller receives the first discovery information sent by a first controller, where the first controller is a controller of the first network domain; The controller receives the second discovery information sent by a second controller, where the second controller is a controller of the second network domain. The method according to claim 6 is characterized in that the cross-domain controller, the first controller and the second controller are three different controllers. The method according to claim 6 is characterized in that at least two of the cross-domain controller, the first controller and the second controller are one controller. The method according to any one of claims 1 to 8 is characterized in that one of the first network domain and the second network domain is an optical network domain, and the other network domain is an Internet Protocol IP network domain. The method according to any one of claims 1 to 8 is characterized in that one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain. A link discovery device, characterized in that it is applied to a controller, and the device comprises: an acquisition module, used to acquire first discovery information and second discovery information, wherein the first discovery information is discovery information of a first link acquired by a first network device based on a clock protocol message, and the second discovery information is discovery information of the first link acquired by a second network device based on the clock protocol message, the first network device is in a first network domain, the second network device is in a second network domain, the network type of the first network domain is different from the network type of the second network domain, and the first link is a cross-domain link between a first port of the first network device and a second port of the second network device; A determination module is used to determine the first link according to the first discovery information and the second discovery information. The device according to claim 11, characterized in that the first discovery information includes indication information of the first port, the second discovery information includes indication information of the second port, at least one of the first discovery information and the second discovery information includes a corresponding relationship between the first port and the second port, The determining module is used to: Determine the first port of the first network device according to the indication information of the first port; Determine the second port of the second network device according to the indication information of the second port; According to the corresponding relationship, it is determined that the first port corresponds to the second port. The apparatus according to claim 12, wherein the first discovery information further includes indication information of the first network device, and the second discovery information further includes indication information of the second network device. The determining module is further used for: determining the first network device according to the indication information of the first network device; The second network device is determined according to the indication information of the second network device. The device according to any one of claims 11 to 13, characterized in that the device further comprises: A sending module is used to send a target policy to the first network device and the second network device before the acquisition module acquires the first discovery information and the second discovery information, wherein the target policy is used to instruct the first network device and the second network device to discover the cross-domain link between the first network domain and the second network domain based on a first clock protocol, and the clock protocol message is a message based on the first clock protocol. The device according to claim 14, characterized in that The acquisition module is further used to acquire first capability information and second capability information before the sending module sends the target policy to the first network device and the second network device, the first capability information being used to indicate that the first port supports the first clock protocol, and the second capability information being used to indicate that the second port supports the first clock protocol; The determination module is further used to determine the target strategy according to the first capability information and the second capability information. The device according to any one of claims 11 to 15, characterized in that the controller is a cross-domain controller, The acquisition module is used to: receiving the first discovery information sent by a first controller, where the first controller is a controller of the first network domain; The second discovery information sent by a second controller is received, where the second controller is a controller of the second network domain. The device according to claim 16 is characterized in that the cross-domain controller, the first controller and the second controller are three different controllers. The device according to claim 16, characterized in that at least two of the cross-domain controller, the first controller and the second controller are one controller. The device according to any one of claims 11 to 18 is characterized in that one of the first network domain and the second network domain is an optical network domain, and the other network domain is an Internet Protocol IP network domain. The device according to any one of claims 11 to 18 is characterized in that one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain. A link discovery device, characterized by comprising a memory and a processor; The memory is used to store computer programs; The processor is used to execute the computer program stored in the memory so that the link discovery device executes the link discovery method according to any one of claims 1 to 10. A link discovery system, characterized by comprising a controller, a first network device and a second network device; The first network device is in a first network domain, the second network device is in a second network domain, and a network type of the first network domain is different from a network type of the second network domain; The controller comprises the link discovery device according to any one of claims 11 to 21. The system according to claim 22 is characterized in that the controller is a cross-domain controller, and the system further includes a first controller and a second controller, the first controller is a controller of the first network domain, and the second controller is a controller of the second network domain. The system according to claim 23 is characterized in that the cross-domain controller, the first controller and the second controller are three different controllers. The system according to claim 23 is characterized in that at least two of the cross-domain controller, the first controller and the second controller are one controller. The system according to any one of claims 22 to 25 is characterized in that one of the first network domain and the second network domain is an optical network domain, and the other network domain is an Internet Protocol IP network domain. The system according to any one of claims 22 to 25 is characterized in that one of the first network domain and the second network domain is a wireless network domain, and the other network domain is a wired network domain. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and when the computer program is executed, the link discovery method according to any one of claims 1 to 10 is implemented. A computer program product, characterized in that the computer program product comprises a program or code, and when the program or code is executed, the link discovery method according to any one of claims 1 to 10 is implemented.