A method, device and system for transmitting node identification

Abstract

The embodiment of the present application discloses a method, device and system for transmitting node identification, which relates to the field of communications and realizes the purpose of reducing the limitations of SR POLICY routing when it is issued, so as to improve network performance. The method specifically includes: the forwarding device sends the node identification to the controller; the forwarding device receives the first SR POLICY routing from the controller, and the destination attribute of the first SR POLICY routing is the node identification; the forwarding device determines that the node identification matches the destination attribute of the first SR POLICY routing, and forwards the traffic message according to the first SR POLICY routing.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communications, and in particular, to a method, device, and system for transmitting node identification. Background Art

[0002] When forwarding traffic in a traditional IP network, when the traffic is forwarded to a node, the next hop device can only be determined by querying the IP routing table on the node. When users plan their networks, they need to add configurations to each node in the network to guide traffic. After the segment routing (SR) technology was proposed, users were given the ability to directly customize the complete forwarding path of traffic.

[0003] When SR technology is applied to Internet Protocol (IP) forwarding, the controller can collect the network topology, calculate the end-to-end SR POLICY route, and send the SR POLICY route to the head node of the path through the border gateway protocol (BGP) SR POLICY address family. The head node generates an SR POLICY tunnel.

[0004] The draft-ietf-idr-segment-routing-te-policy protocol specifies a solution for issuing SR POLICY routes. Specifically, the controller configures the route-target attribute as the BGP router-identity (ID) of the head node when issuing SR POLICY routes. When the head node receives the SR POLICY route, it uses its own BGProuter-ID to match the route-target attribute in the SR POLICY route. If the match succeeds, the SR POLICY route is issued to the SR module in the head node. It is particularly important for the controller to obtain the BGP router-ID of the head node for issuing SR POLICY routes.

[0005] Currently, the controller obtains the BGP router-ID of the forwarding device by reading the configuration information of the forwarding device or querying the forwarding device information through the NETCONF / YANG interface, but both have disadvantages. For example, reading the configuration information depends on the forwarding device to be configured with BGP Router-ID, rather than automatic selection; interface query will encounter performance bottlenecks; once the BGP Router-ID of the forwarding device changes, the controller cannot be informed in time, etc., resulting in limited SR POLICY routing delivery, which in turn leads to poor network performance. Summary of the invention

[0006] The present application provides a method, device and system for transmitting node identification, which reduce the limitations of SR POLICY routing delivery and improve network performance.

[0007] In order to achieve the above objectives, this application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a method for transmitting a node identifier, which may include: when a node identifier of a forwarding device changes, the forwarding device sends the changed node identifier to a controller; the forwarding device receives a first SR POLICY route from the controller, and the destination attribute of the first SR POLICY route is the changed node identifier; the forwarding device determines that the node identifier matches the destination attribute of the first SR POLICY route, and forwards the traffic message according to the first SR POLICY route.

[0009] Through the method for transmitting node identifiers provided in the present application, when the node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device changes, the forwarding device actively sends the changed node identifier to the controller to ensure that the controller obtains the node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device in a timely and accurate manner, reduces the limitations when the SR POLICY route is sent down, and improves network performance.

[0010] The node identifier is used for comparison with the destination attribute of the SR POLICY route when the forwarding device receives the SR POLICY route. The destination attribute of the SR POLICY route is the content of the latest node identifier of the head node.

[0011] In combination with the first aspect, in a possible implementation manner, the forwarding device sends the changed node identifier to the controller, which can be specifically implemented as follows: the forwarding device floods the changed node identifier to report the changed node identifier by a flooding mechanism.

[0012] In combination with the first aspect, in another possible implementation, the forwarding device sends the changed node identifier to the controller, which can be specifically implemented as follows: the forwarding device directly sends the changed node identifier to the controller to avoid reporting redundancy when the forwarding device belongs to multiple self-made domains.

[0013] In combination with the first aspect or any one of the foregoing possible implementations, in another possible implementation, the node identifier may include a BGP Router-ID, or a traffic engineering (TE) Router-ID.

[0014] In combination with the first aspect or any of the above possible implementations, in another possible implementation, the first SR POLICY route may also include a type indication, and the type indication is used to indicate the type of node identifier used by the forwarding device to compare the destination attribute of the SR POLICY route. Accordingly, the forwarding device determines that the node identifier used for comparison with the destination attribute of the SR POLICY route matches the destination attribute of the first SR POLICY route, which can be specifically implemented as follows: the forwarding device determines that the node identifier indicated by the type indication matches the destination attribute of the first SR POLICY route.

[0015] In combination with the first aspect or any of the foregoing possible implementations, in another possible implementation, the destination attribute may be a route-target attribute of the routing destination.

[0016] In a second aspect, the present application provides another method for transmitting a node identifier, which may include: a controller receives a changed node identifier sent by a forwarding device when the node identifier of the forwarding device changes, and the forwarding device is a forwarding device managed by the controller; the controller generates a first SR POLICY route with a head node as the forwarding device, and the destination attribute of the first SR POLICY route is the changed node identifier; the controller sends the first SR POLICY route to the forwarding device.

[0017] Through the method for transmitting node identifiers provided in the present application, when the node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device changes, the forwarding device actively sends the changed node identifier to the controller to ensure that the controller obtains the node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device in a timely and accurate manner, reduces the limitations when the SR POLICY route is sent down, and improves network performance.

[0018] The node identifier is used to configure the destination attribute of the SR POLICY route of the forwarding device as the head node. The destination attribute of the SR POLICY route configured by the controller is the content of the latest node identifier of the head node.

[0019] In combination with the second aspect, in a possible implementation method, the controller receives the changed node identifier sent by the forwarding device when its node identifier changes. Specifically, it can be implemented as follows: the controller receives the changed node identifier sent by the forwarding device when the node identifier of the forwarding device changes, and the changed node identifier is flooded and spread, so as to realize the reporting of the node identifier by the flooding mechanism.

[0020] In combination with the second aspect, in another possible implementation method, the controller receives the changed node identifier sent by the forwarding device when its node identifier changes. Specifically, it can be implemented as follows: the controller receives the changed node identifier sent directly to the controller by the forwarding device when the node identifier of the forwarding device changes, so as to avoid reporting redundancy when the forwarding device belongs to multiple self-made domains.

[0021] In combination with the second aspect or any of the foregoing possible implementations, in another possible implementation, the node identifier may include a BGP Router-ID or a TE Router-ID.

[0022] In combination with the second aspect or any one of the foregoing possible implementations, in another possible implementation, the first SR POLICY route may further include a type indication, where the type indication is used to indicate a destination attribute type of the first SR POLICY route.

[0023] In combination with the second aspect or any of the foregoing possible implementations, in another possible implementation, the destination attribute may be a route-target attribute.

[0024] In a third aspect, the present application further provides a forwarding device, which may include: a sending unit, a receiving unit, a determining unit and a processing unit.

[0025] The sending unit is used to send the changed node identifier to the controller when the node identifier of the forwarding device changes.

[0026] The receiving unit is configured to receive a first SR POLICY route from the controller, where the destination attribute of the first SR POLICY route is a changed node identifier.

[0027] The determining unit is configured to determine whether the node identifier matches a destination attribute of the first SR POLICY route.

[0028] The processing unit is configured to forward the traffic message according to the first SR POLICY route when the determining unit determines that the node identifier matches the destination attribute of the first SR POLICY route.

[0029] It should be noted that the specific implementation of each unit of the third aspect is the same as the method description of the first aspect, and will not be repeated here.

[0030] In a fourth aspect, the present application provides another forwarding device, which can implement the functions in the method example described in the first aspect above, and the functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. The forwarding device can exist in the form of a chip product.

[0031] In conjunction with the fourth aspect, in a possible implementation, the structure of the forwarding device includes a processor and a transceiver, and the processor is configured to support the forwarding device to perform the corresponding functions in the above method. The transceiver is used to support communication between the forwarding device and other devices. The forwarding device may also include a memory, which is used to couple with the processor and store the necessary program instructions and data of the forwarding device.

[0032] In a fifth aspect, the present application further provides a controller, which may include: a receiving unit, a generating unit and a sending unit.

[0033] The receiving unit is used to receive a changed node identifier sent by a forwarding device when the node identifier of the forwarding device changes, and the forwarding device is a forwarding device managed by the controller.

[0034] The generating unit is configured to generate a first SR POLICY route whose head node is the forwarding device, wherein the destination attribute of the first SR POLICY route is the changed node identifier.

[0035] The sending unit is configured to send the first SR POLICY route generated by the generating unit to the forwarding device.

[0036] It should be noted that the specific implementation of each unit of the fifth aspect is the same as the method description of the second aspect, and will not be repeated here.

[0037] In a sixth aspect, the present application provides another controller, which can implement the functions in the method example described in the second aspect above, and the functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. The controller can exist in the form of a chip product.

[0038] In conjunction with the sixth aspect, in a possible implementation, the structure of the controller includes a processor and a transceiver, and the processor is configured to support the controller to perform the corresponding functions in the above method. The transceiver is used to support communication between the controller and other devices. The controller may also include a memory, which is used to couple with the processor and store program instructions and data necessary for the controller.

[0039] In a seventh aspect, the present application provides a communication system, comprising a controller as described in any of the preceding aspects, and one or more forwarding devices as described in any of the preceding aspects controlled by the controller.

[0040] In an eighth aspect, a computer-readable storage medium is provided, comprising instructions, which, when executed on a computer, enables the computer to execute the method for transmission node identification provided by any of the above aspects or any possible implementations.

[0041] In a ninth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the method for transmission node identification provided by any of the above aspects or any possible implementations.

[0042] In a tenth aspect, an embodiment of the present application provides a chip system, which includes a processor and may also include a memory, for implementing the corresponding functions in the above method. The chip system may be composed of a chip, or may include a chip and other discrete devices.

[0043] Among them, various possible implementation methods of any one of the above aspects can be combined under the premise that the solutions are not contradictory.

[0044] It should be noted that the solutions provided in the third to ninth aspects above can achieve the same effect by executing the methods provided in the first or second aspect above or any possible implementation method, and will not be described in detail one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the architecture of a data network provided for this application;

[0046] Figure 2 A schematic diagram of an SR (V6) network architecture provided in an embodiment of the present application;

[0047] Figure 3 A schematic diagram of the structure of a network device provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of a flow chart of a method for transmitting node identification provided in an embodiment of the present application;

[0049] Figure 5 A schematic diagram of a flow chart of another method for transmitting node identification provided in an embodiment of the present application;

[0050] Figure 6 A schematic diagram of a flow chart of another method for transmitting node identification provided in an embodiment of the present application;

[0051] Figure 7A flowchart of another method for transmitting node identification provided in an embodiment of the present application;

[0052] Figure 8 A schematic diagram of the structure of a forwarding device provided in an embodiment of the present invention;

[0053] Fig. 9 A schematic diagram of the structure of another forwarding device provided in an embodiment of the present invention;

[0054] Fig.10 A schematic diagram of the structure of a controller provided by an embodiment of the present invention;

[0055] Fig.11 A schematic diagram of the structure of another controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In the embodiments of the present application, in order to clearly describe the technical solutions of the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially identical functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different. There is no order of precedence or size between the technical features described by the "first" and "second".

[0057] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0058] In the description of this application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In addition, in the description of this application, unless otherwise specified, "multiple" refers to two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0059] In the embodiments of the present application, at least one can also be described as one or more, and multiple can be two, three, four or more, which is not limited in the present application.

[0060] It should be noted that, in the present application, A sends a certain content to B. When A and B are not directly connected in the network architecture, the content can be forwarded step by step through the network elements between A and B so that the content reaches B. This article uniformly describes it as "A sends the content to B."

[0061] In addition, the network architecture and scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application, as known to those skilled in the art. With the evolution of network architecture and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0062] Before describing the embodiments of the present application, the terms involved in the present application are explained here in a unified manner, and will not be explained one by one later.

[0063] A controller is a network device used for centralized management of forwarding devices in a network. The controller can also be used to calculate the transmission path for message forwarding based on the algorithm for calculating the path, and send the information of the forwarding nodes in the transmission path as the route to the head node.

[0064] The head node (also called the first node, entry node or others) refers to the node device that generates messages.

[0065] The transmission path (also called routing) refers to the path composed of node devices that the message passes through during transmission.

[0066] SR POLICY route can refer to the end-to-end transmission path when SR technology is applied to IP transmission. The SR POLICY route can be calculated by the controller, and the controller sends the SR POLICY route to the head node through the BGPSR POLICY address family.

[0067] The BGPSR POLICY address family refers to a method of transmitting SR POLICY routes through the BGP protocol. In different IP technologies, the types of BGPSR POLICY address families are different, and this application does not limit them.

[0068] For example, the BGPSR POLICY address family may include the BGP Internet Protocol version 4 (IPv4) segment routing (SRv4) POLICY address family and the BGPSRv6 POLICY address family. The BGPSRv4 POLICY address family transfers multiprotocol label switching (MPLS) labels to generate SRv4 POLICY routes for forwarding traffic with IPv4 destination addresses; the BGP SRv6 POLICY address family transfers IPv6 segment IDs to generate SRv6 POLICY routes. When SR technology is applied to Internet protocol version 4 (IPv4), the controller can calculate end-to-end IPv4 segment routing (SRv4) POLICY routes and pass the SRv4 POLICY routes through the SRv4 POLICY address family; when SR technology is applied to IPv6, the controller can calculate end-to-end SRv6 POLICY routes and pass the SRv6 POLICY routes through the SRv6 POLICY address family.

[0069] As mentioned above, the draft-ietf-idr-segment-routing-te-policy protocol specifies the solution for issuing SR POLICY routes. When the controller issues SR POLICY routes, it needs to configure the route-target attribute as the BGPProuter-ID of the head node. After the head node BGP receives the SR POLICY route, it uses its own BGP router-ID to match the route-target attribute in the SR POLICY route. Therefore, it is particularly important for the controller to obtain the BGP router-ID of the head node for issuing SR POLICY routes.

[0070] However, the controller cannot obtain the automatically selected BGP router-ID by reading the configuration information of the forwarding device or querying the forwarding device information through the NETCONF / YANG interface. The interface query method will also have a performance bottleneck. In addition, the current acquisition method cannot obtain the BGP router-ID in time when the BGP router-ID changes. All of these will result in the inability to accurately and real-time obtain the BGP router-ID, resulting in limited SR POLICY route delivery, which in turn leads to poor network performance.

[0071] Based on this, an embodiment of the present application provides a method for transmitting node identifiers. When the node identifier used for comparison with the destination attributes of the SR POLICY route in the forwarding device changes, the forwarding device actively sends the changed node identifier to the controller to ensure that the controller obtains the node identifier used for comparison with the destination attributes of the SR POLICY route in the forwarding device in a timely and accurate manner, thereby reducing the limitations when the SR POLICY route is sent down and improving network performance.

[0072] The method for identifying a transmission node provided in the embodiment of the present application is applicable to Figure 1 The data network 10 shown in FIG. 1 may be a communication network or a computer network. The present application does not specifically limit the type of the data network. Figure 1 As shown, the data network 10 includes a controller 101 and a plurality of forwarding devices 102. The forwarding devices 102 may also be referred to as node devices, forwarding nodes, and the like.

[0073] Among them, the controller 101 can be a server or other type of network device with management and path calculation capabilities, and the forwarding device 102 can be a switch or router or other network device with traffic message forwarding capabilities. The actual product form of the controller 101 and the forwarding device 102 is not limited in the embodiments of the present application.

[0074] Specifically, the controller 101 can be used to manage the forwarding device 102. For example, the controller 101 can calculate the end-to-end SR POLICY route and send it to the head node of the route. After receiving the SR POLICY route, the head node uses its own node identifier that is compared with the destination attribute of the SR POLICY route to match the destination attribute in the SR POLICY route. After the match is successful (the comparison results are the same), the head node forwards the traffic message according to the received SR POLICY route.

[0075] It should be noted that the number and specific architecture of each device included in the data network 10 can be configured according to actual needs, and the embodiment of the present application does not limit the scale and specific architecture of the data network 10.

[0076] Furthermore, the forwarding device 102 in the data network 10 may establish a BGP-LS neighbor relationship with the controller 101, and the controller 101 may collect basic network topology through the forwarding device 102 with which the BGP-LS neighbor relationship is established, for calculating end-to-end SR POLICY routing.

[0077] In a possible implementation, when collecting the basic network topology, the controller 101 may also collect the node identifier of each forwarding device managed by it for comparison with the destination attribute of the SR POLICY route to the controller 101 for configuring the destination attribute of the SR POLICY route.

[0078] For example, in Figure 2 In the illustrated SR (V6) network architecture, the forwarding device PE3 and the controller (Controller) establish a BGP-LS neighbor, and PE3 and the Controller establish a BGPSR (V6) POLICY neighbor. The Controller can collect the basic network topology through the BGP-LS neighbor (PE3), and can also collect the node identifier of each forwarding device managed by it for comparison with the destination attribute of the SR POLICY route to the Controller for configuring the route-target attribute of the SR POLICY route.

[0079] When the end-to-end SR POLICY route from PE3 to PE1 calculated by the Controller is PE3-P2-PE1, the Controller can send a BGPSR(V6)POLICY route to the head node PE3. The route-target attribute of the BGPSR(V6)POLICY route is the node identifier used in PE3 for comparison with the destination attribute of the SR POLICY route. After receiving the BGPSR(V6)POLICY route, PE3 uses its own node identifier used for comparison with the destination attribute of the SR POLICY route to compare with the route-target attribute in the BGP SR(V6)POLICY route. After a successful match (the comparison is the same), PE3 forwards traffic packets to PE1 according to the received SR POLICY route.

[0080] The embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0081] On the one hand, an embodiment of the present application provides a network device for executing the method for transmitting node identification provided by the present application. The network device may be a controller or a forwarding device. Figure 3 FIG. 3 is a network device 30 related to various embodiments of the present application. Figure 3 As shown, the network device 30 may include a processor 301 , a memory 302 , and a transceiver 303 .

[0082] Combine the following Figure 3 The components of the network device 30 are described in detail:

[0083] Among them, the memory 302 can be a volatile memory (volatile memory), such as a random-access memory (RAM); or a non-volatile memory (non-volatile memory), such as a read-only memory (ROM), a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD); or a combination of the above types of memories, used to store program codes, configuration files or other content that can implement the method of the present application.

[0084] The processor 301 is the control center of the network device 30. For example, the processor 301 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application, such as one or more microprocessors (digital singnal processors, DSPs), or one or more field programmable gate arrays (FPGAs).

[0085] The transceiver 303 is used to communicate with other devices. The transceiver 303 may be a communication port of the network device 30 or other.

[0086] In a possible implementation, when the network device 30 is a forwarding device, the processor 301 performs the following functions by running or executing the software program and / or module stored in the memory 302 and calling the data stored in the memory 302:

[0087] When the node identifier of the network device 30 changes, the changed node identifier is sent to the controller through the transceiver 303; the first SR POLICY route is received from the controller, and the destination attribute of the first SR POLICY route is the changed node identifier; it is determined that the node identifier matches the destination attribute of the first SR POLICY route, and the traffic message is forwarded according to the first SR POLICY route.

[0088] In another possible implementation, when the network device 30 is a controller, the processor 301 performs the following functions by running or executing the software program and / or module stored in the memory 302 and calling the data stored in the memory 302:

[0089] The changed node identifier sent by the forwarding device when its node identifier changes is received through the transceiver 303, and the forwarding device is a forwarding device managed by the network device 30; a first SR POLICY route with a head node as the forwarding device is generated, and the destination attribute of the first SR POLICY route is the changed node identifier; the first SR POLICY route is sent to the forwarding device through the transceiver 303.

[0090] On the other hand, an embodiment of the present application provides a method for transmitting node identification, which is applied to the interaction process between the controller and the forwarding device it manages. It should be noted that the interaction process between the controller and each forwarding device it manages is similar. In the embodiment of the present application, only the interaction process between the controller and one forwarding device it manages is taken as an example to describe the scheme provided by the present application in detail, and the others are not described one by one.

[0091] like Figure 4 As shown, the method for transmitting node identification provided by the embodiment of the present application may include:

[0092] S401: When a node identifier of a forwarding device changes, the forwarding device sends the changed node identifier to a controller.

[0093] The node identifier is used by the forwarding device to compare the received SR POLICY route with the destination attribute of the SR POLICY route.

[0094] In a possible implementation manner, the node identifier may be a global identifier of the forwarding device.

[0095] Exemplarily, the type of the node identifier may include BGP Router-ID, or TE Router-ID, or system-ID, or other types. Any identifier that can be compared with the destination attribute of the SR POLICY route can be used as the node identifier referred to in this application.

[0096] Optionally, the content of the node identifier may be configured by an administrator of the forwarding device, or automatically selected by the forwarding device, or may change in other ways, which is not limited in the embodiments of the present application.

[0097] Optionally, in S401, the forwarding device sends the changed node identifier to the controller by, but not limited to, any one of the following two possible implementations (implementation A and implementation B).

[0098] Implementation method A: The forwarding device floods and diffuses the changed node identifier.

[0099] In implementation method A, the forwarding device uses the changed node identifier (the latest content of the node identifier) ​​as an attribute of flooding, and floods it within the domain. The controller's BGP-LS neighbor device collects the changed node identifier when collecting the network topology, and the controller's BGP-LS neighbor device reports the changed node identifier to the controller.

[0100] For example, assuming that the node is identified as BGP Router-ID, when the BGP Router-ID changes, the changed (latest) BGP Router-ID can be used as an attribute of IGP flooding in S401 and flooded in the domain through IGP. When the BGP-LS neighbor of the Controller collects the IGP topology, the IGP module in the forwarding device can report the changed BGP Router-ID as the Node attribute to the BGP-LS neighbor, and the BGP-LS neighbor encapsulates the collected BGP Router-ID information of the forwarding device into a BGP-LS Node route and reports it to the controller.

[0101] Implementation method B: The forwarding device sends the changed node identifier to the controller.

[0102] In implementation method A, the flooding method within the domain has certain disadvantages. When there are multiple IGP domains on the forwarding device, the same forwarding device will report multiple node identifiers to the controller, resulting in redundancy. Based on this, in implementation method B, the forwarding device can send the changed node identifier to the controller in S401.

[0103] Specifically, in implementation B, a message for reporting a node identifier for comparison with a destination attribute of the SR POLICY route may be added.

[0104] Furthermore, in implementation method B, the forwarding device may directly send the changed node identifier to the controller, or may send the changed node identifier to the controller through forwarding by other devices, which is not limited in this embodiment of the present application.

[0105] S402: The controller receives a changed node identifier sent by a forwarding device when the node identifier of the forwarding device changes.

[0106] It should be noted that the changed node identifier received by the controller in S402 is the changed node identifier sent by the forwarding device in S401, which will not be described in detail here.

[0107] In one possible implementation, corresponding to implementation A in S401, the controller in S402 receives the changed node identifier sent by the forwarding device when the node identifier of the forwarding device changes, which can specifically include: the controller receives the changed node identifier of the forwarding device and floods it when the node identifier of the forwarding device changes.

[0108] In another possible implementation, corresponding to implementation B in S401, the controller in S402 receives the changed node identifier sent by the forwarding device when the node identifier of the forwarding device changes, which can specifically include: the controller receives the changed node identifier sent by the forwarding device when the node identifier of the forwarding device changes.

[0109] It should be noted that the controller may receive, through S402, a changed node identifier sent by each forwarding device managed by the controller when its node identifier changes.

[0110] After S402, after determining the transmission path according to the algorithm for calculating the transmission path, the controller configures the destination attribute of the SR POLICY route as the latest node identifier of the head node, and then sends the SR POLICY route to the head node.

[0111] For example, after S402, after the controller determines that the head node is a transmission path of the forwarding device described in the present application according to the algorithm for calculating the transmission path, the process from S403 to S406 may be executed.

[0112] S403: The controller generates a first SR POLICY route with the head node being the forwarding device.

[0113] The destination attribute of the first SR POLICY route is the node identifier of the forwarding device after the change.

[0114] Exemplarily, the destination attribute may be a route-target attribute.

[0115] Furthermore, the first SR POLICY route may further include a type indication, which may be used to indicate the type of the destination attribute of the first SR POLICY route. The type may be BGP Router-ID, or TE Router-ID or others.

[0116] For example, when the type of the node identifier is TE Router-ID, the type indication included in the first SR POLICY route may be used to indicate that the type of the destination attribute of the first SR POLICY route is TE Router-ID.

[0117] Exemplarily, Table 1 illustrates a message format of a destination attribute part of a first SR POLICY route, which includes a type indication.

[0118] Table 1

[0119]

[0120] It should be noted that Table 1 is only an example of a message format of the destination attribute part of the first SR POLICY route, and does not specifically limit the message format of the destination attribute part of the first SR POLICY route.

[0121] S404: The controller sends a first SR POLICY route to the forwarding device.

[0122] Specifically, in S404, the controller network topology sends a first SR POLICY route to the forwarding device serving as the head node.

[0123] Optionally, the controller may send the first SR POLICY route to the forwarding device according to the network topology. The route may be sent directly or forwarded through other devices, which is not elaborated in this application.

[0124] S405: The forwarding device receives a first SR POLICY route from the controller.

[0125] It should be noted that the first SR POLICY route received by the forwarding device from the controller in S405 is the first SR POLICY route sent by the controller to the forwarding device in S404, which will not be described in detail here.

[0126] Further, after the forwarding device receives the first SR POLICY route from the controller in S405, the forwarding device compares its own node identifier for comparison with the destination attribute of the SR POLICY route with the destination attribute of the first SR POLICY route. If they are the same, it is determined to be a match and S406 is executed; if its own node identifier for comparison with the destination attribute of the SR POLICY route is different from the destination attribute of the first SR POLICY route, it is determined to be a mismatch and the first SR POLICY route is ignored.

[0127] Optionally, when the first SR POLICY route also includes a type indication, the forwarding device compares its own node identifier for comparison with the destination attribute of the SRPOLICY route with the destination attribute of the first SR POLICY route. Specifically, it can be implemented as follows: the forwarding device compares the node identifier indicated by the type indication with the destination attribute of the first SR POLICY route according to the indication of the type indication.

[0128] S406: The forwarding device determines that its own node identifier matches the destination attribute of the first SR POLICY route, and the forwarding device forwards the traffic message according to the first SR POLICY route.

[0129] The forwarding device determining in S406 that its own node identifier matches the destination attribute of the first SR POLICY route may be replaced by: the forwarding device determining that its own node identifier for comparison with the destination attribute of the SR POLICY route matches the destination attribute of the first SR POLICY route.

[0130] Optionally, when the first SR POLICY route also includes a type indication, the forwarding device determines that the node identifier matches the destination attribute of the first SR POLICY route, including: the forwarding device determines that the node identifier indicated by the type indication matches the destination attribute of the first SR POLICY route.

[0131] Through the method for transmitting node identifiers provided in the present application, when the node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device changes, the forwarding device actively sends the changed node identifier to the controller to ensure that the controller obtains the node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device in a timely and accurate manner, reduces the limitations when the SR POLICY route is sent down, and improves network performance.

[0132] It should be noted that Figure 4 The execution order of each step included in the can be configured according to actual needs. Figure 4 It only illustrates a possible execution order and does not limit the execution order of each step.

[0133] Below Figure 2 The solution provided in the present application is illustrated by taking the process of transmitting the node identifier of the forwarding device P1 to the controller in the illustrated SR (V6) network architecture as an example.

[0134] Embodiment 1: The node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device is BGPRouter-ID, and the forwarding device sends the BGP Router-ID to the controller through intra-domain flooding.

[0135] like Figure 5 As shown, the process of transmitting the BGP Router-ID of the forwarding device P1 to the controller in Example 1 is illustrated. The method for transmitting the node identifier provided in Example 1 may include:

[0136] S501. The interior gateway protocol (IGP) module in P1 collects BGP Router-ID information from the BGP module.

[0137] S502: When the BGP Router-ID changes, the IGP module in P1 floods the collected changed BGP Router-ID information to the surrounding neighbors (PE3).

[0138] For example, in S502, a threshold limit value (TLV) may be added to the IGP flooding information to carry the BGP Router-ID. The embodiment of the present application does not limit the location, content, form, etc. of the newly added TLV.

[0139] S503: The BGP-LS module on PE3 collects topology information from the IGP module in PE3, and the IGP module in PE3 reports the collected BGP Router-ID information to the BGP-LS module on PE3.

[0140] S504. PE3 sends a BGP-LS update message to the controller.

[0141] In S504, after PE3 collects the IGP topology information, it encapsulates the topology information into a BGP-LS update message and publishes it to the controller through the BGP-LS neighbor.

[0142] Exemplarily, PE3 may carry BGP Router-ID in the BGP-LS Node route attribute to report the BGP Router-ID to the controller. Table 2 illustrates the message format of carrying BGP Router-ID in the BGP-LS Node route attribute.

[0143] Table 2

[0144]

[0145] It should be noted that Table 2 is only an example of the message format of carrying BGP Router-ID in the BGP-LS Node route attribute, and is not a specific limitation on the message format of carrying BGP Router-ID in the BGP-LS Node route attribute.

[0146] Embodiment 2: The node identifier used for comparison with the destination attribute of the SR POLICY route in the forwarding device is BGPRouter-ID. When the BGP Router-ID changes, the forwarding device actively sends the BGP Router-ID to the controller.

[0147] like Figure 6 As shown, the process of transmitting the BGP Router-ID of the forwarding device P1 to the controller in Example 2 is illustrated. The method for transmitting the node identifier provided in Example 2 may include:

[0148] S601. The BGP module in P1 collects the BGP Router-ID of P1.

[0149] S602. P1 sends a BGP-LS update message to PE3.

[0150] In S602, when the BGP Router-ID changes, P1 encapsulates the collected BGP Router-ID of P1 into a BGP-LS update message and publishes it to PE3.

[0151] Exemplarily, the overall message format of the BGP-LS update message may be as shown in Table 3.

[0152] Table 3

[0153]

[0154] Exemplarily, the local node description field in the overall message format of the BGP-LS update message shown in Table 3 can be used to carry the TLV shown in Table 2.

[0155] S603. After receiving the BGP-LS update message issued by P1, PE3 issues a BGP-LS update message to the controller.

[0156] Embodiment 3: In the forwarding device, the node identifier used for comparison with the destination attribute of the SR POLICY route is TE Router-ID. When the TE Router-ID changes, the forwarding device actively sends the TE Router-ID to the controller.

[0157] like Figure 7 As shown, the process of transmitting the TE Router-ID of the forwarding device P1 to the controller in Embodiment 3 is illustrated. The method for transmitting the node identification provided in Embodiment 3 may include:

[0158] S701. When the TE Router-ID of P1 changes, the IGP module in P1 floods the topology information carrying the TE Router-ID to the neighbor PE3.

[0159] S702. The BGP-LS module on PE3 collects topology information from the IGP module in PE3.

[0160] S703 and PE3 send a BGP-LS update message to the controller.

[0161] In S703, the BGP-LS module on PE3 encapsulates the topology information into a BGP-LS update message and publishes it to the controller through the BGP-LS neighbor.

[0162] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the working principle of the interaction process between the forwarding device and the controller. It is understandable that the above-mentioned forwarding device and the controller include hardware structures and / or software modules corresponding to the execution of each function in order to realize the above-mentioned functions. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0163] The embodiment of the present application can divide the forwarding device and the controller into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0164] In the case of dividing each functional module into corresponding functional modules, Figure 8 FIG. 8 is a schematic diagram showing a possible structure of the forwarding device 80 involved in the above embodiment. Figure 8 As shown, the forwarding device 80 may include: a sending unit 801, a receiving unit 802, a determining unit 803 and a processing unit 804. The sending unit 801 is used to execute Figure 4 Process S401 in the receiving unit 802 is used to execute Figure 4 Process S405 in the determination unit 803 is used to perform Figure 4 Process S406 in the process; processing unit 804 is used to execute Figure 4 In the process S406. Among them, all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0165] In the case of an integrated unit, Fig. 9FIG. 1 shows a possible structural diagram of the forwarding device 90 involved in the above embodiment. Fig. 9 As shown, the forwarding device 90 may include: a processing module 901 and a communication module 902. The processing module 901 is used to control and manage the actions of the forwarding device 90, and the communication module 902 is used to communicate with other devices. For example, the processing module 901 is used to execute Figure 4 The processing module 901 can also be used to execute the process S406 through the communication module 902. Figure 4 The forwarding device 90 may further include a storage module 903 for storing program codes and data of the forwarding device 90 .

[0166] Among them, the processing module 901 can be Figure 3 The processor 301 in the physical structure of the network device 30 shown can be a processor or a controller. For example, it can be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processing module 901 can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc. The communication module 902 can be Figure 3 The transceiver 303 in the physical structure of the network device 30 shown in the figure, the communication module 902 can be a communication port, or can be a transceiver, a transceiver circuit or a communication interface. Alternatively, the above communication interface can realize communication with other devices through the above elements with transceiver functions. The above elements with transceiver functions can be realized by antennas and / or radio frequency devices. The storage module 903 can be Figure 3 The physical structure of the network device 30 is shown as a memory 302.

[0167] When the processing module 901 is a processor, the communication module 902 is a transceiver, and the storage module 903 is a memory, the embodiment of the present application Fig. 9 The forwarding device 90 involved may be Figure 3 The network device 30 is shown.

[0168] As mentioned above, the forwarding device 80 or forwarding device 90 provided in the embodiments of the present application can be used to implement the corresponding functions in the methods implemented by the above-mentioned embodiments of the present application. For the convenience of explanation, only the parts related to the embodiments of the present application are shown. For specific technical details not disclosed, please refer to the embodiments of the present application.

[0169] In the case of dividing each functional module into corresponding functional modules, Fig.10 FIG. 1 shows a possible structural diagram of the controller 100 involved in the above embodiment. Fig.10 As shown, the controller 100 may include: a receiving unit 1001, a generating unit 1002 and a sending unit 1003. The receiving unit 1001 is used to execute Figure 4 Process S402 in; generating unit 1002 is used to execute Figure 4 The sending unit 1003 is used to execute Figure 4 In the process S404. All relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0170] In the case of an integrated unit, Fig.11 FIG. 1 shows a possible structural diagram of the controller 110 involved in the above embodiment. Fig.11 As shown, the controller 110 may include: a processing module 1101 and a communication module 1102. The processing module 1101 is used to control and manage the actions of the controller 110, and the communication module 1102 is used to communicate with other devices. Figure 4 The processing module 1101 can also be used to execute the process S403 through the communication module 1102. Figure 4 The controller 110 may further include a storage module 1103 for storing program codes and data of the controller 110 .

[0171] Among them, the processing module 1101 can be Figure 3 The processor 301 in the physical structure of the network device 30 shown can be a processor or a controller. For example, it can be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processing module 1101 can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc. The communication module 1102 can be Figure 3 The transceiver 303 in the physical structure of the network device 30 shown in the figure, the communication module 1102 can be a communication port, or can be a transceiver, a transceiver circuit or a communication interface. Alternatively, the above communication interface can realize communication with other devices through the above elements with transceiver functions. The above elements with transceiver functions can be realized by antennas and / or radio frequency devices. The storage module 1103 can be Figure 3 The physical structure of the network device 30 is shown as a memory 302.

[0172] When the processing module 1101 is a processor, the communication module 1102 is a transceiver, and the storage module 1103 is a memory, the embodiment of the present application Fig.11 The controller 110 involved may be Figure 3 The network device 30 is shown.

[0173] As mentioned above, the controller 100 or controller 110 provided in the embodiments of the present application can be used to implement the corresponding functions in the methods implemented by the above-mentioned embodiments of the present application. For the convenience of explanation, only the parts related to the embodiments of the present application are shown. For specific technical details not disclosed, please refer to the embodiments of the present application.

[0174] On the other hand, an embodiment of the present application provides a communication system, including a controller, and one or more forwarding devices managed by the controller.

[0175] As another form of this embodiment, a computer-readable storage medium is provided, on which instructions are stored. When the instructions are executed, the method for transmitting node identification in the above method embodiment is executed.

[0176] As another form of this embodiment, a computer program product containing instructions is provided. When the computer program product is run on a computer, the computer executes the method for transmitting node identification in the above method embodiment.

[0177] The embodiment of the present application further provides a chip system, which includes a processor for implementing the technical method of the embodiment of the present application. In one possible design, the chip system also includes a memory for storing the necessary program instructions and / or data of the embodiment of the present application. In one possible design, the chip system also includes a memory for the processor to call the application code stored in the memory. The chip system can be composed of one or more chips, and can also include chips and other discrete devices, which is not specifically limited in the embodiment of the present application.

[0178] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0179] Those skilled in the art should be aware that in one or more of the above examples, the functions described in this application can be implemented with hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein the communication media includes any medium that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that can be accessed by a general or special-purpose computer. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described system, device, and unit can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0180] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical or other forms.

[0181] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0182] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may be physically included separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0183] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform some steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0184] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for transmitting a node identifier, characterized in that: The method comprises: When the node identifier of the forwarding device changes, the forwarding device sends the changed node identifier to the controller; the node identifier is used for comparison with the destination attribute of the SR POLICY route when the forwarding device receives the SR POLICY route; The forwarding device receives a first SR POLICY route from the controller, where a destination attribute of the first SR POLICY route is a changed node identifier; The forwarding device determines that the node identifier matches a destination attribute of the first SR POLICY route, and the forwarding device forwards the traffic message according to the first SR POLICY route.

2. The method according to claim 1, characterized in that The forwarding device sends the changed node identifier to the controller, including: The forwarding device floods and diffuses the changed node identifier.

3. The method according to claim 1 or 2, characterized in that: The node identifier includes a Border Gateway Protocol Router-ID or a Traffic Engineering Router-ID.

4. The method according to claim 1 or 2, characterized in that: The first SR POLICY route further includes a type indication, where the type indication is used to indicate a type of the node identifier that the forwarding device compares with a destination attribute of the first SR POLICY route; The forwarding device determines that the node identifier matches a destination attribute of the first SR POLICY route, including: The forwarding device determines that the node identifier indicated by the type indication matches a destination attribute of the first SR POLICY route.

5. The method according to claim 1 or 2, characterized in that: The destination attribute is the route-target attribute of the routing destination.

6. A method for transmitting a node identifier, characterized in that: The method comprises: The controller receives a changed node identifier sent by a forwarding device when the node identifier of the forwarding device changes, and the forwarding device is a forwarding device managed by the controller; the node identifier is used for comparison with a destination attribute of an SR POLICY route when the forwarding device receives the SR POLICY route; The controller generates a first SR POLICY route whose head node is the forwarding device, where a destination attribute of the first SR POLICY route is a changed node identifier; The controller sends the first SR POLICY route to the forwarding device.

7. The method according to claim 6, characterized in that The controller receives a changed node identifier sent by a forwarding device when the node identifier of the forwarding device changes, including: The controller receives a changed node identifier of the forwarding device that is flooded when the node identifier of the forwarding device changes.

8. The method according to claim 6 or 7, characterized in that: The node identifier includes a Border Gateway Protocol Router-ID or a Traffic Engineering Router-ID.

9. The method according to claim 6 or 7, characterized in that: The first SR POLICY route further includes a type indication, where the type indication is used to indicate a type of a destination attribute of the first SR POLICY route.

10. The method according to claim 6 or 7, characterized in that: The destination attribute is the route-target attribute of the routing destination.

11. A forwarding device, characterized in that: The forwarding device comprises: a sending unit, configured to send the changed node identifier to the controller when the node identifier of the forwarding device changes; the node identifier is used for comparing the destination attribute of the SR POLICY route with the SR POLICY route when the forwarding device receives the SR POLICY route; a receiving unit, configured to receive a first SR POLICY route from the controller, wherein a destination attribute of the first SR POLICY route is a changed node identifier; a determining unit, configured to determine that the node identifier matches a destination attribute of the first SR POLICY route; and a processing unit, configured to forward the traffic message according to the first SR POLICY route when the determining unit determines that the node identifier matches the destination attribute of the first SR POLICY route.

12. The forwarding device according to claim 11, characterized in that: The sending unit is specifically used for: Node ID after flooding changes.

13. The forwarding device according to claim 11 or 12, characterized in that: The node identifier includes a Border Gateway Protocol Router-ID or a Traffic Engineering Router-ID.

14. The forwarding device according to claim 11 or 12, characterized in that: The first SR POLICY route further includes a type indication, where the type indication is used to indicate a type of the node identifier that the forwarding device compares with a destination attribute of the first SR POLICY route; The determining unit is specifically used to determine that the node identifier indicated by the type indication matches the destination attribute of the first SRPOLICY route.

15. The forwarding device according to claim 11 or 12, characterized in that: The destination attribute is the route-target attribute of the routing destination.

16. A controller, characterized in that: The controller comprises: a receiving unit, configured to receive a changed node identifier sent by a forwarding device when the node identifier of the forwarding device changes, wherein the forwarding device is a forwarding device managed by the controller; the node identifier is used for comparison with a destination attribute of an SR POLICY route when the forwarding device receives the SR POLICY route; A generating unit, configured to generate a first SR POLICY route whose head node is the forwarding device, wherein the destination attribute of the first SR POLICY route is the changed node identifier; A sending unit is used to send the first SR POLICY route generated by the generating unit to the forwarding device.

17. The controller according to claim 16, characterized in that: The receiving unit is specifically used for: The receiving device floods the changed node identifier when the node identifier of the forwarding device changes.

18. The controller according to claim 16 or 17, characterized in that: The node identifier includes a Border Gateway Protocol Router-ID or a Traffic Engineering Router-ID.

19. The controller according to claim 16 or 17, characterized in that: The first SR POLICY route further includes a type indication, where the type indication is used to indicate a type of a destination attribute of the first SR POLICY route.

20. The controller according to claim 16 or 17, characterized in that: The destination attribute is the route-target attribute of the routing destination.

21. A forwarding device, characterized in that: The forwarding device includes: a processor and a memory; The memory is connected to the processor; the memory is used to store computer instructions, and when the processor executes the computer instructions, the forwarding device executes the method for identifying a transmission node as described in any one of claims 1 to 5.

22. A controller, characterized in that: The controller includes: a processor and a memory; The memory is connected to the processor; the memory is used to store computer instructions, and when the processor executes the computer instructions, the controller executes the method for identifying a transmission node as described in any one of claims 6 to 10.

23. A communication system, characterized in that: It comprises the controller as claimed in claim 22, and one or more forwarding devices as claimed in claim 21 controlled by the controller.

24. A computer-readable storage medium, characterized in that: The method comprises instructions, which, when executed on a computer, enable the computer to execute the method for identifying a transmission node according to any one of claims 1 to 10.

25. A computer program product, characterized in that The invention comprises instructions, which, when executed on a computer, enable the computer to execute the method for identifying a transmission node according to any one of claims 1 to 10.

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