A method and apparatus for protection switching in a Segment Routing (SR) network

Abstract

The embodiment of the present application discloses a protection switching method, providing a way to transmit protection switching messages in the SRv6 data plane. Through this way, after a failure occurs in a certain end-to-end transmission path of the forward service traffic of the first node, the first node can switch the transmission path of its forward service traffic to another end-to-end transmission path and send the forward service traffic through the switched transmission path. By using this way, the first node only needs to store the information of the aforementioned another transmission path by itself, without the need for intermediate nodes to maintain a large amount of path status information and path configuration information, which is beneficial to the deployment and operation and maintenance of the SRv6 network.

Description

[0001] This application claims the priority of a Chinese patent application with an application date of February 2, 2021, an application number of 202110143569.3, and an invention title of "A Method, Apparatus, and System for Implementing Linear Protection in a Segment Routing Network", the entire content of which is incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and in particular, to a protection switching method and apparatus. Background Art

[0003] Segment Routing (SR) is a protocol for forwarding data packets on a network designed based on the source routing concept. SR based on the Multi-Protocol Label Switching (MPLS) forwarding plane is called SR-MPLS, and SR based on the IPv6 forwarding plane is called SRv6. To avoid traffic transmission interruption caused by node and / or link failures in the current transmission path, traffic transmission needs to be protected. A known technology is the Topology-Independent Loop-free Alternate (TI-LFA) protection based on Segment Routing. TI-LFA can theoretically support node and link protection for any topology and can achieve fast reroute (FRR) protection. For each link or each next-hop node on the forwarding path, TI-LFA determines a neighbor node that is not the primary next hop. If the shortest path from this neighbor node to the destination node does not pass through the source node, this neighbor node is used as an acyclic backup next-hop node.

[0004] However, in the protection technology based on TI-LFA, it is usually necessary to calculate corresponding protection paths for each node or each link and install them on each intermediate node. The intermediate nodes need to maintain a large amount of path status information and path configuration information, the configuration of the intermediate nodes is complex, and the processing capacity requirements for the intermediate nodes are high. The operation and maintenance management is difficult.

[0005] Therefore, in the SR network, how to provide a simple and efficient protection switching mechanism has become one of the problems to be solved currently. Summary of the Invention

[0006] The embodiments of this application provide a protection switching method, which can provide a mechanism for protecting and switching an end-to-end SRv6 path. This mechanism does not require intermediate nodes to maintain a large amount of path status information and path configuration information.

[0007] In a first aspect, an embodiment of the present application provides a protection switching method. This method can be executed by a first communication device, for example. The first communication device can correspond to a head node or an intermediate node on a first path. In one example, the first communication device can obtain a first SRv6 packet (in the present invention, an SRv6 packet refers to an IPv6 packet with a Segment Routing Header (SRH)). The first SRv6 packet includes a first protection switching message. After the first communication device obtains the first protection switching message, it can send the first SRv6 packet to the tail node of the first path. The first path mentioned here is the path used to forward the first SRv6 packet. Among them, the first protection switching message can be used to request the tail node of the first path to perform path switching. Thus, it can be seen that with this solution, the tail node of the first path can be requested to perform path switching, so that when a certain path fails, the tail node can switch the service traffic to other paths, thereby ensuring the quality of service of the service traffic. Moreover, when requesting the tail node of the first path to perform path switching through the first protection switching message, the tail node can switch the service traffic to the backup path based on the first protection switching message, without the need for intermediate nodes to maintain a large amount of path status information and path configuration information, which can reduce the requirement for the data processing ability of the intermediate nodes.

[0008] In one implementation, the first protection switching message can be carried in the protocol payload of the first SRv6 packet.

[0009] In one implementation, the first protection switching message can be carried in the extension header of the first SRv6 packet. The extension header mentioned here can be an HBH option header, or a DOH, or an SRH.

[0010] In one implementation, in addition to including the first protection switching message, the first SRv6 packet can further include first indication information, and the first indication information is used to indicate the first protection switching message. In this way, the tail node of the first path can determine that the first SRv6 packet includes the first protection switching message based on the first indication information.

[0011] In one implementation, the first indication information indicating the first protection switching message can be a first path identifier, where the first path identifier is used to identify the first path. In this way, other semantics can be given to the first path identifier in addition to identifying the first path. For this case, the tail node of the first path can determine that the first SRv6 packet includes the first protection switching message based on the first path identifier.

[0012] In one implementation, after a second path fails, the first communication device may send a first SRv6 packet to the tail node of the first path to request the tail node of the first path to switch the traffic transmission path from the second path to the third path. Among them, the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path. For this case, the first SRv6 packet may include an identifier of the path to be switched, that is, an identifier of the second path. In one example, the first path and the second path may use the same identifier. In other words, the first path identifier is also used to identify the second path, and the first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path. For this case, based on the first segment identifier, the tail node can both determine that the first SRv6 packet includes the first protection switching message and determine that the first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path.

[0013] In one implementation, considering that the second path can be used to transmit multiple types of service traffic, and the quality of service requirements for different service traffic may be different. To meet the quality of service of the service traffic with high quality of service requirements as much as possible, in one example, after the second path fails, the transmission path of the service traffic with high quality of service requirements can be preferentially switched from the second path to the third path. For this case, the first SRv6 packet may also carry an identifier of at least one service transmitted on the second path, so that the first protection switching message can be used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

[0014] In one implementation, the identifier of at least one service transmitted on the second path can be carried by the aforementioned first path identifier. In this way, based on the first path identifier, the tail node can both determine that the first SRv6 packet includes the first protection switching message and determine that the first protection switching message is used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

[0015] In one implementation, for an SRv6 packet, the segment list included in its SRH may include a pathsegment field. Among them, the path segment field is used to carry a path segment identifier, and the value of the path segment identifier is used to identify an SRv6 path. Therefore, in one example, the first path identifier may be a first path segment identifier used to identify the first path.

[0016] In one implementation, the identifier of the second path and the identifier of the first path can be different identifiers. For this case, the first SRv6 packet may further include a second path identifier, which is used to identify the second path. In this way, the tail node of the first path can determine, based on the second path identifier, that the first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path, where the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path.

[0017] In one implementation, if it is necessary to switch the transmission path of the service traffic with high quality of service requirements from the second path to the third path preferentially after a failure occurs in the second path. The foregoing second path identifier is further used to identify at least one service transmitted on the second path. In this way, based on the second path identifier, the tail node can determine that the first protection switching message is used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

[0018] In one implementation, the second path identifier is: a second path segment identifier.

[0019] In one implementation, in order to implement the common path for the forward and reverse paths of services, after receiving the first SRv6 packet, the tail node of the first path can send a second SRv6 packet to the head node of the first path through the third path. The second SRv6 packet includes a second protection switching message, and the second protection switching message is a response message to the first protection switching message. In one example, after receiving the second SRv6 packet, the head node of the first path can switch the transmission path of its sent packet from the fourth path to the first path based on the second protection switching message. The first path and the third path mentioned here are reverse common path paths. Thus, the common path for the forward and reverse paths can be implemented.

[0020] In one implementation, the foregoing first indication information and the first protection switching message can both be carried in the extended header of the first SRv6 packet. In one example, a first TLV field can be extended in the extended header of the first SRv6 packet, and the extended TLV field is used to carry the first indication information and the first protection switching message.

[0021] In one implementation, the first TLV does not carry other types of control and management messages except for carrying the first protection switching message.

[0022] In one implementation, in addition to carrying the first protection switching message, the first TLV may also carry other types of control and management messages. At this time, the first TLV is an associated channel TLV. The associated channel TLV includes a channel type field for carrying the first indication information, and the value field of the associated channel TLV is used to carry the first protection switching message.

[0023] In one implementation, the first SRV6 packet includes an associated channel, which can carry different types of control channels. One type of control channel is a protection switching channel, which is used to carry the first indication information and the first protection switching message. In this way, through the associated channel, multiple different control and management functions can be implemented.

[0024] In one implementation, in addition to including an associated channel, the first SRV6 packet may also include second indication information for indicating the associated channel. In this way, a node receiving the first SRV6 packet can determine that the first SRV6 packet includes an associated channel according to the second indication information.

[0025] In one implementation, at least one of the control channels carried by the associated channel may include, for example, one or more of an OAM channel, a fault indication channel, a resource management channel, a signaling communication channel SCC, and a management communication channel MCC. Among them: the control and management messages carried by the OAM channel may be, for example, OAM messages, which are a general term for a series of messages for implementing operation, maintenance, and management of an end-to-end IPv6, such as an SRv6 path; the control and management messages carried by the fault indication channel may be, for example, fault indication messages, which are used to record the fault indication information of the first path; the control and management messages carried by the resource management channel may be, for example, resource management messages, which are used to implement resource management of a certain path, such as the first path; SCC is used to provide a separate channel between two nodes of an IPv6 path to transmit control information; MCC is used to provide a separate channel between two nodes of an IPv6 path to transmit management information.

[0026] In one implementation, the control and management messages carried by the resource management channel may include, for example, one or more of a resource reservation request message, a resource status update message, and a resource reservation cancellation message. Among them: The resource reservation request message is used to instruct the nodes on the first path to reserve resources; the resource status update message is used to collect the available resources of the nodes on the first path; the resource reservation cancellation message is used to cancel a certain resource reservation request; the first path mentioned here is the transmission path of the first IPv6 packet. It can be understood that when the control channel carried by the associated channel includes the resource management channel, the first IPv6 packet includes a resource reservation request message, or a resource status update message, or a resource reservation cancellation message.

[0027] In one implementation, the foregoing first protection switching message may be an APS message or a PSC message.

[0028] In one implementation, a custom APS message may include a protection type field, a reason field for requesting protection switching, and a path field after switching. Among them: The protection type field is used to indicate the type of the protection protocol, the reason field for requesting protection switching is used to indicate the reason for requesting the tail node of the first SRv6 packet to perform path switching; the path field after switching is used to indicate the path after switching based on the indication information. The tail node of the first SRv6 packet can switch the service traffic to the path after switching based on the path information after switching. Optionally, the APS message may further include a primary path information field and a backup path information field. The primary path information field is used to carry the information of the primary path, and the backup path information field is used to carry the information of the backup path. The path after switching is the primary path or the backup path.

[0029] Second aspect, an embodiment of the present application provides a protection switching method, which can be executed by a first communication device. The first communication device can correspond to the tail node on the first path. In an example, the first communication device can receive a first SRv6 packet, and the first SRv6 packet includes a first protection switching message. After receiving the first protection switching message, the first communication device can perform corresponding operations based on the first protection switching message. The first path mentioned here is the path for forwarding the first SRv6 packet. Among them, the first APS message can be used to request the tail node of the first path to perform path switching. It can be seen that with this solution, the tail node can perform path switching based on the request of the first protection switching message, so that when a certain path fails, the tail node can switch the service traffic to other paths, thereby ensuring the quality of service of the service traffic. Moreover, when requesting the tail node of the first path to perform path switching through the first protection switching message, the tail node can switch the service traffic to the backup path based on the first protection switching message, without the need for intermediate nodes to maintain a large amount of path status information and path configuration information, which can reduce the data processing capacity requirements of the intermediate nodes.

[0030] In one implementation, the first APS message is used to request the tail node of the first path to switch the transmission path of the traffic from the second path to the third path. Among them, the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path. The first path is the path for forwarding the first SRv6 packet.

[0031] In one implementation, if the first APS message is used to request the tail node of the first path to switch the transmission path of the traffic from the second path to the third path, the first communication device can switch the transmission path of the traffic from the second path to the third path based on the first APS message, thereby avoiding affecting the normal transmission of the service traffic due to the failure of the second path.

[0032] In one implementation, in order to implement the common path of the forward and reverse paths of the service, after receiving the first SRv6 packet, the tail node of the first path can send a second SRv6 packet to the head node of the first path through the third path. The second SRv6 packet includes a second protection switching message, and the second protection switching message is a response message to the first protection switching message. In an example, after receiving the second SRv6 packet, the head node of the first path can switch the transmission path of its sent packet from the fourth path to the first path based on the second protection switching message. The first path and the third path mentioned here are reverse common path paths. Thus, the common path of the forward and reverse paths can be implemented.

[0033] In a third aspect, an embodiment of the present application provides a protection switching method, which can be applied to a first node. In one example, after a first SRv6 path fails, the first node can switch the sending path of the forward service traffic of the first node from the first SRv6 path to a second SRv6 path, and send the forward service traffic through the second SRv6 path. Among them, the forward service traffic is the service traffic sent by the first node to the second node. The first SRv6 path is the path between the first node and the second node. The first node is the head node of the first SRv6 path, and the second node is the tail node of the first SRv6 path. The first SRv6 path and the second SRv6 path have the same head node and tail node. In other words, the first SRv6 path and the second SRv6 path can be backups of each other. It can be seen that with this solution, after the first SRv6 path fails, the first node can switch the forward service traffic originally forwarded through the first SRv6 path to the second SRv6 path for forwarding, thus ensuring the quality of service of the forward service traffic.

[0034] In one implementation, after the first SRv6 path fails, in addition to switching the path for sending the forward service traffic, the first node can also switch the path for receiving the reverse service traffic. In one example, the first node can also switch the receiving path of the reverse service traffic of the first node from a third SRv6 path to a fourth SRv6 path, and receive the reverse service traffic through the fourth SRv6 path. Among them: the reverse service traffic is the traffic sent by the second node to the first node. The head node of the third SRv6 path is the second node, and the tail node of the third SRv6 path is the first node. The third SRv6 path and the fourth SRv6 path have the same head node and tail node. In one example, the fourth SRv6 path and the second SRv6 path are two-way common path paths, so that the forward and reverse paths can share the same path.

[0035] In one implementation, a first segment list can be pre-stored in the first node, and the first segment list is used to describe the set of segment identifiers (SIDs) of the second SRv6 path. When the first node sends the forward service traffic through the second SRv6 path, the forward service traffic can be encapsulated using the first segment list.

[0036] In one implementation, the first node may switch the transmission path of the forward service traffic from the first SRv6 path to the second SRv6 path based on the first SRv6 packet sent by the second node. The first SRv6 packet includes a first protection switching message. After receiving the first SRv6 packet, the first node may switch the transmission path of the forward service traffic from the first SRv6 path to the second SRv6 path according to the first protection switching message.

[0037] In one implementation, the first SRv6 packet includes first information, which is used to indicate the path to be switched. In other words, the first information is used to identify the first SRv6 path. After receiving the first SRv6 packet, the first node may determine, according to the first information, that the first protection switching message is used to request the first node to switch the transmission path of the forward service traffic from the first SRv6 path to the second SRv6 path.

[0038] In one implementation, the first node may pre - save the correspondence between the first information and the first segment list. In this way, when the first node receives the first SRv6 packet including the first information, it can determine the first segment list indicating the switched - to path according to this correspondence.

[0039] In one implementation, after the first node determines the first segment list indicating the switched - to path according to the correspondence, if it needs to send forward service traffic, it may encapsulate the forward service traffic by using the first segment list, so as to send the forward service traffic through the second SRv6 path.

[0040] In one implementation, the first information may be the first path segment identifier used to indicate the first SRv6 path.

[0041] In a fourth aspect, the present application provides a communication device, including: a transceiver unit and a processing unit. Wherein: the transceiver unit is used to perform the transceiver operations described in the first aspect and any item of the first aspect above, and the processing unit is used to perform other operations except the transceiver operations described in the first aspect and any item of the first aspect above. Or, the transceiver unit is used to perform the transceiver operations described in the second aspect and any item of the second aspect above, and the processing unit is used to perform other operations except the transceiver operations described in the second aspect and any item of the second aspect above. Or, the transceiver unit is used to perform the transceiver operations described in the third aspect and any item of the third aspect above, and the processing unit is used to perform other operations except the transceiver operations described in the third aspect and any item of the third aspect above.

[0042] Fifth aspect, the present application provides a communication device, which includes a memory and a processor; the memory is used to store program code; the processor is used to run the instructions in the program code, so that the communication device executes the method described in the above first aspect and any item of the first aspect, or so that the communication device executes the method described in the above second aspect and any item of the second aspect, or so that the communication device executes the method described in the above third aspect and any item of the third aspect.

[0043] Sixth aspect, the present application provides a communication device, which includes a communication interface and a processor. Among them: the communication interface is used to perform the transceiver operations described in the above first aspect and any item of the first aspect, and the processor is used to perform other operations except the transceiver operations described in the above first aspect and any item of the first aspect. Or, the communication interface is used to perform the transceiver operations described in the above second aspect and any item of the second aspect, and the processor is used to perform other operations except the transceiver operations described in the above second aspect and any item of the second aspect. Or, the communication interface is used to perform the transceiver operations described in the above third aspect and any item of the third aspect, and the processor is used to perform other operations except the transceiver operations described in the above third aspect and any item of the third aspect.

[0044] Seventh aspect, the present application provides a computer-readable storage medium, which is characterized in that instructions are stored in the computer-readable storage medium, and when it runs on a computer, it causes the computer to execute the method described in the above first aspect and any item of the first aspect, or causes the computer to execute the method described in the above second aspect and any item of the second aspect, or causes the computer to execute the method described in the above third aspect and any item of the third aspect.

[0045] Eighth aspect, the present application provides a communication system, which includes: a communication device described in the above fourth aspect or the above fifth aspect or the above sixth aspect and executing the method described in the above first aspect and any item of the first aspect, a communication device described in the above fourth aspect or the above fifth aspect or the above sixth aspect and executing the method described in the above second aspect and any item of the second aspect.

[0046] Ninth aspect, the present application provides a communication system, which includes: a communication device described in the above fourth aspect or the above fifth aspect or the above sixth aspect and executing the method described in the above first aspect and any item of the first aspect, a communication device described in the above fourth aspect or the above fifth aspect or the above sixth aspect and executing the method described in the above third aspect and any item of the third aspect. Description of the Drawings

[0047] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0048] Figure 1a It is a schematic diagram of an exemplary application scenario;

[0049] Figure 1b It is a schematic diagram of an exemplary application scenario provided by the embodiments of the present application;

[0050] Figure 2 It is a signaling interaction diagram of a protection switching method provided by the embodiments of the present application;

[0051] Figure 3a It is a schematic diagram of the structure of a message 1 provided by the embodiments of the present application;

[0052] Figure 3b It is a schematic diagram of the structure of a message 1 provided by the embodiments of the present application;

[0053] Figure 3c-1 It is a schematic diagram of the structure of an associated channel TLV provided by the embodiments of the present application;

[0054] Figure 3c-2 It is a schematic diagram of the structure of an associated channel TLV provided by the embodiments of the present application;

[0055] Figure 3d It is a schematic diagram of the structure of another APS message provided by the embodiments of the present application;

[0056] Figure 4 It is a signaling interaction diagram of a protection switching method provided by the embodiments of the present application;

[0057] Figure 5a It is a schematic diagram of the structure of a message 1 provided by the embodiments of the present application;

[0058] Figure 5b It is a schematic diagram of the structure of a message 1 provided by the embodiments of the present application;

[0059] Figure 5c It is a schematic diagram of the structure of a message 1 provided by the embodiments of the present application;

[0060] Figure 5d It is a schematic diagram of the structure of a message 1 provided by the embodiments of the present application;

[0061] Figure 6Schematic flowchart of a protection switching method provided by an embodiment of the present application;

[0062] Figure 7 Schematic flowchart of a protection switching method provided by an embodiment of the present application;

[0063] Figure 8 Schematic flowchart of a protection switching method provided by an embodiment of the present application;

[0064] Figure 9 Schematic structural diagram of a communication device provided by an embodiment of the present application;

[0065] Figure 10 Schematic structural diagram of a communication device provided by an embodiment of the present application;

[0066] Figure 11 Schematic structural diagram of a communication device provided by an embodiment of the present application. Detailed implementation manners

[0067] An embodiment of the present application provides a message processing method, providing a mechanism for linearly protecting and switching an end-to-end SRv6 path.

[0068] For a certain end-to-end SRv6 path, such as the first path, if any physical link or intermediate node fails on the first path, the service traffic originally transmitted through the first path cannot be transmitted normally, affecting the service quality.

[0069] Currently, SRv6 usually adopts a fast rerouting mechanism to protect against link or node failures. Before the first path fails, for each intermediate node and each physical link on the first path, a local loop-free path needs to be calculated to bypass the intermediate node or the physical link, so that when the intermediate node or physical link fails, the service traffic is transmitted through the corresponding local loop-free path. In one example, for each intermediate node on the first path, a next hop that is not on the shortest forwarding path needs to be calculated. When the calculated next hop does not pass through the head node of the first path, the calculated next hop is used as the next hop of the intermediate node on the backup path.

[0070] However, this local rerouting protection method requires the intermediate node to save the local rerouting protection path, the complexity of the network intermediate node is relatively high, and it is not easy for the operation and maintenance personnel to track the detour path after the rerouting protection. In addition, the fast rerouting technology is difficult to ensure the co-routing of the forward and reverse paths of the service, that is, it cannot ensure that the forward path and the reverse path of the service pass through the same set of intermediate nodes and links. Therefore, it does not meet the special requirements of two-way co-routing of transmission services such as frequency / time synchronization.

[0071] Regarding the mechanism of the foregoing fast rerouting, in combination with Figure 1a it will be described as follows. Figure 1a FIG. Figure 1a is a schematic diagram of an exemplary application scenario.

[0072] As Figure 1a shown, a provider edge (PE) device PE1 is connected to a provider (P) device P1. P1 is respectively connected to P2 and P4. P2 is connected to P3. P3 is connected to P4. P4 is connected to PE2. The optimal path between PE1 and PE2 is PE1-P1-P4-PE2. In one example, a segment list of the path P2-P3-P4 is maintained in node P2. When the link P1-P4 fails, P2 can switch the traffic sent to P4 to be forwarded on the path P2-P3-P4. Of course, Figure 1a it is only shown for the convenience of understanding. For a network with a more complex network structure, the path configuration information maintained by an intermediate node such as P1 far exceeds the foregoing segment list of P2-P3-P4. Moreover, node P1 also needs to maintain a large amount of path status information.

[0073] It should be noted that in the embodiments of the present application, the segment list in the SRv6 packet is used to indicate the transmission path of the SRv6 packet. The segment list may include several segment identifiers (SIDs). One SID is used to indicate a certain intermediate node passed through in the transmission path, or one SID is used to indicate an SRv6 adjacent link included in the transmission path. Among them: The adjacent link between two nodes refers to the link used for direct communication between the two nodes. When one node sends a packet to another node through the adjacent link, the other node is the next hop of the previous node.

[0074] The inventors of the present application found that if it is possible to directly perform end-to-end protection switching on the first path when the first path fails, and switch the service traffic originally transmitted on the first path to be transmitted on its backup path, then only the information of the backup path such as the segment list corresponding to the backup path needs to be stored on the edge node, without the need for intermediate nodes to maintain a large amount of path status information and path configuration information, which can ensure the normal transmission of the service traffic originally transmitted on the first path and can bring a better experience in service management and operation and maintenance. In one example, it can also meet the requirements of the same forward and reverse paths for transmission services such as frequency / time synchronization, which is more beneficial for providing carrier-grade services in the SRv6 network.

[0075] In view of this, the embodiments of the present application provide an end-to-end protection switching method, which can perform protection switching on the end-to-end SRv6 path without requiring intermediate nodes to provide local rerouting protection. Next, in combination with Figure 1b the application scenario shown below, the end-to-end protection switching method provided by the embodiments of the present application will be introduced.

[0076] Refer to Figure 1b , which is a schematic diagram of an exemplary application scenario provided by the embodiments of the present application.

[0077] As Figure 1b shown, a customer edge device (CE) CE1 can communicate with CE2 through network 100. In one example, network 100 can be an SRv6 network.

[0078] PE1, PE2, P1, and P2 are all nodes in the SRv6 network. Among them:

[0079] PE1 can send a message to PE2 through the path PE1-P1-PE2, and PE1 can also send a message to PE2 through the path PE1-P2-PE2. The paths PE1-P1-PE2 and PE1-P2-PE2 are backups of each other. In one example, the path PE1-P1-PE2 can be called the working path or the primary path, and the path PE1-P2-PE2 can be called the protection path or the backup path.

[0080] Similarly, PE2 can send a message to PE1 through the path PE2-P1-PE1, and PE2 can also send a message to PE1 through the path PE2-P2-PE1. The paths PE2-P1-PE1 and PE2-P2-PE1 are backups of each other. In one example, the path PE2-P1-PE1 can be called the working path or the primary path, and correspondingly, the path PE2-P2-PE1 can be called the protection path or the backup path.

[0081] In Figure 1b the scenario shown, the paths PE1-P1-PE2 and PE2-P1-PE1 are bidirectionally common paths, and the paths PE1-P2-PE2 and PE2-P2-PE1 are bidirectionally common paths. Among them, two paths being bidirectionally common means that the set of nodes included in the two paths is the same, but the order in which each node appears in the two transmission paths of the mutually reverse common paths is opposite. Bidirectional common paths can also be called mutually reverse common paths. In the present application, the two are often used interchangeably.

[0082] The protection switching method provided by the embodiments of the present application can be applied to Figure 1bThe scene shown, when the protection switching method provided by the embodiments of the present application is applied to Figure 1b In the shown scene, when a failure occurs in the path PE2 - P1 - PE1 (i.e., any one or more physical links or any one or more intermediate nodes fail), the service traffic originally transmitted through the path PE2 - P1 - PE1 can be switched to be transmitted through the path PE2 - P2 - PE1. Further, in a two-way common path network scenario, the service traffic originally transmitted through the path PE1 - P1 - PE2 can also be switched to be transmitted through the path PE1 - P2 - PE2.

[0083] It should be noted that Figure 1b This is only an exemplary application scenario diagram of the embodiments of the present application, and it does not constitute a limitation to the embodiments of the present application. Figure 1b The shown scene can be applied to the 1:1 protection switching or 1 + 1 protection switching scenario, and the solution provided by the embodiments of the present application can further be applied to the 1:n protection switching scenario. Among them:

[0084] 1:1 protection switching means that one working path corresponds to one protection path, and the protection path does not transmit service traffic, or other service traffic is transmitted on the protection path, and the priority of the other service traffic is lower than the priority of the service traffic transmitted on the working path;

[0085] 1 + 1 protection switching means that one working path corresponds to one protection path, and service traffic is transmitted on both the protection path and the working path;

[0086] 1:n protection switching means that n working paths correspond to one shared protection path.

[0087] In some examples, Figure 1bEdge nodes of the network 100 shown, such as PE1 and PE2, can locally store the correspondence between services and service encapsulation information. For example, they can store the correspondence between service identifiers and service encapsulation information. When an edge node (such as PE1) receives a service packet from a user-side device (such as CE1), it can determine the encapsulation information corresponding to the service packet according to the correspondence, so as to encapsulate the service packet. The service identifier mentioned here can be, for example, the identifier number of the service, such as the service number, or it can be other strings. The embodiments of the present application do not make specific limitations. The service identifier can be carried in the path segment field mentioned below, or it can be carried in other fields different from the path segment field. In one example, when the service identifier is the service number, the service identifier can be carried in the path segment field; when the service identifier is other strings, the service identifier can be carried in other fields different from the path segment field. The service encapsulation information mentioned here includes the encapsulation information of the service packet and service information. The encapsulation information of the service packet includes, for example, but is not limited to IPv6; the service information includes, for example, but is not limited to one or more of the service-related information such as the virtual local area network (VLAN) identifier and the Internet Protocol Version 4 (IPv4) address prefix of the local network.

[0088] The protection switching method provided by the embodiments of the present application can be applied to Figure 1b the scenario shown. In one example, the path PE1-P2-PE2 is called path 1, the path PE2-P1-PE1 is called path 2, the path PE2-P2-PE1 is called path 3, and the path PE1-P1-PE2 is called path 4. In one example:

[0089] The tail node of path 1 can, after path 2 fails, switch the sending path of the forward service traffic of the tail node of path 1 from path 2 to path 3, and send the forward service traffic through path 3. The SRv6 packet sent through path 3 includes the segment list indicating path 3 mentioned above. Correspondingly, the head node of path 1 can switch the path for receiving the forward service traffic from path 2 to path 3, and receive the forward service traffic from path 3. For ease of description, the tail node of path 1 is called the first node, and the head node of path 1 is called the second node. Then, the forward service traffic of the first node refers to the service traffic sent from the first node to the second node, and the reverse service traffic of the first node refers to the service traffic sent from the second node to the first node.

[0090] In the embodiments of the present application, considering that for a certain service, the transmission of its service traffic is two-way. For example: for Service 1, PE1 can send the service traffic corresponding to Service 1 to PE2, and PE2 can also send the service traffic corresponding to Service 1 to PE1. And for Figure 1b the network scenario shown, for the convenience of maintaining and managing service traffic, it is generally required that two-way service traffic be transmitted on the working path at the same time, or two-way service traffic be transmitted on the protection path at the same time. That is: the service traffic sent by PE1 to PE2 is transmitted on the working path, and the service traffic sent by PE2 to PE1 is also transmitted on the working path; or, the service traffic sent by PE1 to PE2 is transmitted on the protection path, and the service traffic sent by PE2 to PE1 is also transmitted on the protection path.

[0091] In view of this, in an optional manner, after the tail node of Path 1 switches the traffic to Path 3, the head node of Path 1 can switch the path for sending service traffic from Path 4 to Path 1 and send the service traffic through Path 1. It can be understood that the SRv6 packet sent through Path 1 includes the aforementioned segment list indicating Path 1. Correspondingly, the tail node of Path 1 can switch the path for receiving the service traffic sent by the head node of Path 1 from Path 4 to Path 1 and receive the service traffic sent by the head node of Path 1 from Path 4. In other words, the tail node of Path 1 can switch the receiving path of its own reverse service traffic from Path 4 to Path 1 and receive the reverse service traffic through Path 1. Among them, the reverse service traffic of the tail node of Path 1 refers to the service traffic sent by the head node of Path 1 to the tail node of Path 1.

[0092] It can be understood that the above Path 1 and Path 3 are reverse common path paths to each other, and Path 2 and Path 4 are reverse common path paths to each other. Using this solution, after a failure occurs on Path 2, the service traffic originally transmitted on Path 2 can be switched to Path 3 for transmission, and the service traffic originally transmitted on Path 4 can be switched to Path 1 for transmission, so that two-way service traffic is transmitted on the protection path, facilitating the management of service traffic.

[0093] Currently, SRv6 does not define how to implement the transmission of linear protection switching messages on the data plane, and the present application provides a protection switching method that can implement the transmission of protection switching messages on the data plane in the SRv6 network.

[0094] The protection switching message in the embodiments of this application can be an automatic protection switching (APS) message or a protection switching coordination (PSC) message, and the embodiments of this application do not make specific limitations. In the following Method 100 and Method 200, the protection switching message is taken as an APS message as an example for illustration. The APS in the above embodiments can also be replaced with a PSC message, and the format of the PSC message can refer to the description part of Request for Comments (RFC) 6378 of The Internet Engineering Task Force (IETF), which will not be elaborated here.

[0095] Next, Figure 2 introduce the protection switching method provided by the examples of this application. Figure 2 It is a signaling interaction diagram of a protection switching method provided by an embodiment of this application. Figure 2 The communication device 1 in Method 100 shown can correspond to Figure 1b the node PE1 shown, and the communication device 2 in Method 100 can correspond to Figure 1b the node PE2 shown.

[0096] The communication device mentioned in the embodiments of this application can be a network device such as a switch or a router, or a part of the components on the network device, such as a single board or a line card on the network device, can be a functional module on the network device, or can also be a chip for implementing the method of this application. The embodiments of this application do not make specific limitations. The communication devices can be directly connected through, for example, but not limited to, an Ethernet cable or an optical cable.

[0097] In the embodiments of this application, the communication device corresponding to the node means that the communication device can be the node itself or a part of the components on the node. The nodes in the embodiments of this application can be network devices such as switches or routers.

[0098] In the following description of the embodiments of this application, unless otherwise specified, "traffic" is "service traffic", and "traffic" and "service traffic" can be used interchangeably.

[0099] Figure 2 The Method 100 shown can, for example, include the following S101 - S106.

[0100] Through the following S101 - S103, after path 2 fails, the tail node of path 1 can switch the sending path of the forward service traffic of the tail node of path 1 from path 2 to path 3, and send the forward service traffic through path 3. Correspondingly, the head node of path 1 can switch the path for receiving the forward service traffic from path 2 to path 3, and receive the forward service traffic from path 3.

[0101] After the following S104 - S106, after the tail node of path 1 switches the traffic to path 3, the head node of path 1 can switch the path for sending service traffic from path 4 to path 1, and send the service traffic through path 1. Correspondingly, the tail node of path 1 can switch the path for receiving the service traffic sent by the head node of path 1 from path 4 to path 1, and receive the service traffic sent by the head node of path 1 from path 4. In other words, the tail node of path 1 can switch the receiving path of its own reverse service traffic from path 4 to path 1, and receive the reverse service traffic through path 1. The reverse service traffic of the tail node of path 1 refers to the service traffic sent by the head node of path 1 to the tail node of path 1.

[0102] The aforementioned path 1 and path 3 are reverse common path paths to each other, and path 2 and path 4 are reverse common path paths to each other. After executing the above S101 - S106, after path 2 fails, the service traffic originally transmitted on path 2 can be switched to path 3 for transmission, and the service traffic originally transmitted on path 4 can be switched to path 1 for transmission, so that the two - way service traffic is transmitted on the protection path, facilitating the management of the service traffic.

[0103] S101: Communication device 1 generates message 1, and message 1 includes APS message 1. Message 1 is an SRv6 message.

[0104] In the embodiment of the present application, message 1 is a protocol message, and the transmission path of message 1 is path 1.

[0105] In an implementation manner of the embodiment of the present application, APS message 1 can be carried in the protocol payload of message 1.

[0106] In another implementation manner of the embodiment of the present application, APS message 1 can be carried in the IPv6 extension header of message 1.

[0107] In one example, the extension header of message 1 mentioned in the embodiments of the present application may be a hop-by-hop (HBH) option header. In other words, the APS message 1 may be included in the HBH option header of message 1. In yet another example, the extension header of message 1 mentioned in the embodiments of the present application may be a destination option header (DOH). In other words, the APS message 1 may be included in the DOH of message 1. In another example, the extension header of message 1 mentioned in the embodiments of the present application may be a segment routing header (SRH). In other words, the APS message 1 may be included in the SRH of message 1.

[0108] In one example, in addition to including the APS message 1, message 1 may further include indication information 1, and the indication information 1 is used to indicate the APS message 1. In one example, the indication information 1 is also carried in the extension header of message 1. Wherein, the extension header carrying the indication information 1 and the APS message 1 may be the same extension header. For example, both the indication information 1 and the APS message 1 are carried in the SRH. The extension header carrying the indication information 1 and the APS message 1 may also be different extension headers. For example, the indication information 1 is carried in the SRH, and the APS message 1 is carried in the DOH. It can be understood that if the extension headers carrying the indication information 1 and the APS message 1 are the same extension headers, the node receiving message 1 can obtain the APS message 1 by parsing one extension header. Therefore, in a preferred solution, the indication information 1 and the APS message 1 are carried in the same extension header. Of course, the indication information 1 may also be carried in the protocol payload of message 1, which is not limited herein.

[0109] The communication device 1 may locally maintain an APS state machine, which is used to process APS messages. The communication device 1 may periodically generate a message including the APS message according to the local state machine and send the message including the APS message.

[0110] In one example, if the path with the node corresponding to the communication device 2 as the head node and the node corresponding to the communication device 1 as the tail node does not fail, the APS message 1 may not request the node corresponding to the communication device 2 to perform path switching.

[0111] In yet another example, the communication device 1 may generate the message 1 after a failure occurs in path 2. Herein: the head node of path 2 is the node corresponding to communication device 2, and the tail node of path 2 is the node corresponding to communication device 1. In other words, communication device 1 may generate the message 1 after a failure occurs in the path with the tail node of path 1 as the head node and the head node of path 1 as the tail node. For this case, the APS message 1 is used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3, where path 2 and path 3 have the same head node and tail node. Path 3 can be considered as a backup path of path 2. Herein: path 1 may correspond to Figure 1b PE1-P2-PE2 in Figure 1b path 2 may correspond to Figure 1b PE2-P1-PE1 in

[0112] In an implementation manner of the embodiment of the present application, the foregoing indication information 1 may be a path identifier 1 capable of identifying path 1. Herein, the path identifier 1 may be carried in the SRH of the message 1, or may be carried in the HBH option header or DOH of the message 1, which is not limited herein.

[0113] Considering that for an SRv6 message, the segment list included in its SRH may include a path segment field. Herein, the path segment field includes 128 bits, and the path segment field is used to carry a path segment identifier, and the path segment identifier is used to identify an SRv6 path. When the message 1 includes a path segment field, the value of this path segment field is used to identify the transmission path of the message 1. The path segment field may include a locator field and a function field. In one example, the foregoing path identifier 1 may be a path segment identifier 1, and the path segment identifier 1 mentioned herein may be used to identify path 1. For this case, the foregoing path identifier 1 may be carried in the SRH of the message 1. Similarly, the foregoing APS message 1 may also be carried in the SRH of the message 1. For this case, in one example, if the path segment identifier 1 is used to identify path 1 and indicate the APS message 1, then in one example, the locator field of the path segment identifier 1 may indicate path 1, and the function field of the path segment identifier 1 may indicate the APS message 1. In the following description, the path identifier 1 is taken as an example of the path segment identifier 1 for illustration.

[0114] As described above, after a failure occurs in path 2, the communication device 1 may generate the message 1. At this time, the APS message 1 is used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3. For this case, the identifier of the path to be switched (i.e., path 2) may also be carried in the message 1. In this way, this APS message 1 can be used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3.

[0115] In one implementation, for the 1:1 protection switching scenario or the 1+1 protection switching scenario, the identifier of path 2 and the identifier of path 1 may be the same identifier. For this case, the path segment identifier 1, which is the foregoing indication information 1, may also be used to identify path 2. In this way, in the message 1, a path segment field can be used to indicate both the APS message 1 and the path to be switched. When a node that receives the message 1 processes the APS message 1, it can determine, according to this path segment field, that this APS message 1 is used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3. For this case, the message structure of the message 1 may refer to Figure 3a as shown. Figure 3a It is a schematic structural diagram of a message 1 provided by an embodiment of the present application.

[0116] In Figure 3a :

[0117] The path segment 1 field is used to carry the foregoing path segment identifier 1;

[0118] The APS message 1 may correspond to Figure 3a the shaded part shown. Regarding each field in the APS message 1, reference may be made to the relevant description in RFC7271, which will not be elaborated here. Regarding other fields in the IPv6 header, reference may be made to the relevant description part in RFC8200, and regarding other fields in the SRH, reference may be made to the relevant description part in RFC8754, which will not be elaborated here.

[0119] It should be noted that Figure 3a is only shown as an example and does not constitute a limitation to the embodiments of the present application. In some embodiments, in addition to including Figure 3a the fields shown, the message 1 may also include other fields, which will not be elaborated one by one here.

[0120] It should be noted that for the 1:1 protection switching scenario or the 1+1 protection switching scenario, in addition to being able to identify Path 1 and Path 2, the aforementioned path segment identifier 1 can also identify Path 3 and Path 4. The Path 4 mentioned here is the backup path of Path 1. In other words, Path 1 and Path 4 have the same head node and tail node. For example, for the Figure 1b PE1-P2-PE2 shown in Figure 1b Figure 1, Path 4 corresponds to

[0121] PE1-P1-PE2 shown in Figure 2. In some embodiments, considering that Path 2 can be used to transmit multiple types of service traffic, and different service traffic may have different requirements for service quality. To best meet the service quality requirements of service traffic with high service quality requirements, in one example, after Path 2 fails, the transmission path of service traffic with high service quality requirements can be preferentially switched from Path 2 to Path 3. For this case, the message 1 can also carry the identifier of at least one service transmitted on Path 2, so that the APS message 1 can be used to request the tail node of Path 1 to switch the transmission path of the at least one service from Path 2 to Path 3.

[0122] In one example, the identifier of the at least one service can be carried by the path segment identifier 1. For example, the identifier of the at least one service can be carried by a part of the bits in the path segment identifier 1. At this time, the path segment identifier 1 can not only be used to indicate the APS message 1, but also be used to identify Path 2 and the at least one service transmitted on Path 2. The at least one service mentioned here can be, for example, the aforementioned service traffic with high service quality requirements.

[0123] In one implementation, for a certain node, the identifier of the service carried by this node can correspond to a range of path segment identifiers. For this case, the path segment identifier corresponding to this node can be used to identify both the path and the service transmitted on this path. For example, the identifier of Service 1 corresponds to the range of path segment identifier 1, and the path segment identifier a is the segment list within the range of path segment identifier 1, then the path segment identifier a can be used to identify both the path and Service 1.

[0124] In another example, the identifier of the at least one service can be carried in other ways, such as carried by other fields. As an example, for the Figure 3a message 1 shown in Figure 3, a field can be added after the APS message 1 to carry the identifier of the at least one service.

[0125] In another implementation, the identifier of path 2 and the identifier of path 1 can be different identifiers. For this case, message 1 may further include path identifier 2. As an example, path identifier 2 can be path segment identifier 2, and path segment identifier 2 is used to identify path 2. In the following description, path identifier 2 is taken as path segment identifier 2 as an example for illustration. For this case, the node receiving message 1 can determine based on the path segment identifier 2 that APS message 1 is used to request the tail node of path 1 to switch the transmission path for the traffic sent by the tail node from path 2 to path 3. For this case, the message structure of message 1 can refer to Figure 3b as shown. Figure 3b FIG. Figure 3b is a schematic structural diagram of a message 1 provided by an embodiment of the present application.

[0126] In Figure 3b :

[0127] The path segment 1 field is used to carry the aforementioned path segment identifier 1;

[0128] The path segment 2 field is used to carry the aforementioned path segment identifier 2;

[0129] APS message 1 can correspond to Figure 3b the shaded part shown. Regarding each field in APS message 1, reference can be made to the relevant description in RFC7271, which will not be elaborated here. Regarding other fields in the IPv6 header, reference can be made to the relevant description part in RFC8200, and regarding other fields in the SRH, reference can be made to the relevant description part in RFC8754, which will not be elaborated here.

[0130] It should be noted that Figure 3b is shown only as an example and does not constitute a limitation to the embodiments of the present application. In some embodiments, in addition to including the Figure 3b fields shown, message 1 may further include other fields, which will not be elaborated one by one here.

[0131] It should be noted that for the 1:1 protection switching scenario or the 1+1 protection switching scenario, in addition to being able to identify path 1, the aforementioned path segment identifier 1 can also identify path 4. Here, path 4 mentioned is the backup path of path 1. In other words, path 1 and path 4 have the same head node and tail node. For example, for the Figure 1b shown PE1-P2-PE2 corresponding to path 1, path 4 corresponds to Figure 1bThe PE1-P1-PE2 shown above. In addition to being able to identify path 2, the aforementioned path segment identifier 2 can also identify path 3. Of course, the path segment identifier of path 4 and that of path 1 can also be different, and the path segment identifier of path 3 and that of path 2 can also be different. The embodiments of the present application do not make specific limitations. For the 1:n protection switching scenario, the path segment identifier corresponds one-to-one with the path it identifies.

[0132] As described above, considering that path 2 can be used to transmit multiple types of service traffic, and different service traffic may have different requirements for service quality. In order to meet the service quality of the service traffic with high requirements for service quality as much as possible, in one example, after path 2 fails, the transmission path of the service traffic with high requirements for service quality can be preferentially switched from path 2 to path 3. For this case, the message 1 can also carry the identifier of at least one service transmitted on path 2. In this way, the APS message 1 can be used to request the tail node of path 1 to switch the transmission path of the at least one service from path 2 to path 3.

[0133] In one example, the identifier of the at least one service can be carried by the path segment identifier 2. For example, the identifier of the at least one service can be carried by some bits in the path segment identifier 2. At this time, the path segment identifier 2 can not only be used to identify path 2, but also identify at least one service transmitted on path 2. The at least one service mentioned here can be, for example, the aforementioned service traffic with high requirements for service quality.

[0134] In another example, the identifier of the at least one service can be carried in other ways, such as by other fields. As an example, for Figure 3b the message 1 shown above, a field can be added after the APS message 1, for example, after the pathsegment 2 field, to carry the identifier of the at least one service.

[0135] In yet another implementation manner of the embodiments of the present application, the aforementioned indication information 1 can be other information in addition to the path segment identifier 1. In one example, the extended header of the message 1 can include a TLV field 1, which is used to carry the indication information 1 and the APS message 1.

[0136] In one example, the TLV field 1 is only used to carry the indication information 1 and the APS message 1.

[0137] In yet another example, in addition to carrying indication information 1 and APS information 1, the TLV field 1 can also be used to carry other information. For this case, the TLV field 1 can be an associated channel TLV, and the associated channel TLV includes a field for carrying indication information 1 and a field for carrying APS information 1. In one example, the associated channel TLV includes a channel type field, and this channel type field is used to carry the aforementioned indication information 1, and the value field of the associated channel TLV field is used to carry the APS message 1.

[0138] It should be noted that, in one example, the message 1 may include an associated channel, and this associated channel can carry different types of control channels, and one of the control channels is an APS channel, and this APS channel is used to carry the aforementioned indication information 1 and APS message 1. In one example, the aforementioned TLV field 1 is an associated channel TLV, and the associated channel is carried in the associated channel TLV.

[0139] Regarding the associated channel, it should be noted that:

[0140] The associated channel can provide control channels. In this application, through one associated channel, different types of control channels can be provided. In other words, different types of control channels are carried by the associated channel provided in this application. According to requirements, one associated channel can carry one or more control channels. Each type of control channel can carry at least one control management message.

[0141] The control channel is used to carry control management messages, and among them, one control channel can be used to carry at least one control management message.

[0142] The control management message is a message that can control and / or manage a certain path, such as a certain tunnel. The embodiments of this application do not specifically limit the format of the control management message and the specific content included in the control management message, as long as the control management message can achieve the corresponding control and / or management function. In one example, one type of control management message can be used to achieve one control function or management function.

[0143] In this application, when the aforementioned TLV field 1 is an associated channel TLV, the control channels carried by the associated channel include an APS channel, and the APS channel is used to carry the aforementioned indication information 1 and APS message 1.

[0144] In one example, if the message 1 includes an associated channel, the message 1 further includes indication information 2 for indicating the associated channel. A node that receives the message 1 can determine that the message 1 includes an associated channel according to the indication information 2. In one example, the indication information 2 can be carried in the associated channel TLV. For example, the indication information 2 can be carried in the type field of the associated channel TLV. In yet another example, a field not yet defined in the extended header of the message 1 can also be used to carry the indication information 2. For example, the flags field in the SRH of the message 1 can be used to carry the indication information 2.

[0145] Regarding the associated channel TLV, reference can be made to Figure 3c-1 and Figure 3c-2 for understanding. Figure 3c-1 and Figure 3c-2 Both are schematic diagrams of the structure of an associated channel TLV provided by embodiments of the present application.

[0146] Figure 3c-1 Shows the structure of the associated channel TLV when the associated channel carries a control channel. Figure 3c-2 Shows the structure of the associated channel TLV field when the associated channel carries multiple control channels.

[0147] In Figure 3c-1 and Figure 3c-2 :

[0148] The type field 301 is used to carry the aforementioned indication information 2.

[0149] The channel type fields 302 and 304 are used to carry the channel type. In one example, the channel type field 302 or the channel type field 304 is used to carry the aforementioned indication information 1.

[0150] The reserved field is a reserved field to facilitate subsequent expansion of the associated channel TLV. This reserved field is an optional field.

[0151] The value field 303 is used to carry at least one control management message carried by the channel type indicated by the channel type field 302. In one example, if the channel type field 303 carries the aforementioned indication information 1, the value field 303 is used to carry the APS message 1. In yet another example, the value field 303 can include at least one sub-TLV. One sub-TLV is used to carry a control management message. The length of the value field 303 can be determined according to the control management message it carries or can be a fixed length, which is not limited herein.

[0152] The value field 305 is used to carry at least one control and management message carried by the channel type 304. In one example, if the channel type field 304 carries the aforementioned indication information 1, the value field 305 is used to carry the APS message 1; in another example, the value field 305 may include at least one sub-TLV, and one sub-TLV is used to carry a control and management message. The length of the value field 305 can be determined according to the control and management message it carries, or it can be a fixed length, which is not limited here.

[0153] It should be noted that the structure of the APS message carried in the associated channel TLV in the embodiments of the present application can be the structure of the APS message mentioned in RFC 7271, or it can be other structures. For example, reference can be made to Figure 3d , Figure 3d which is a schematic diagram of the structure of another APS message provided by the embodiments of the present application. In one example, Figure 3d the APS message shown can be carried in Figure 3c-1 the value field 303 shown or Figure 3c-2 the value field 305 shown.

[0154] The primary path information field is used to carry the information of the primary path, such as carrying the identifier of the primary path;

[0155] The standby path information field is used to carry the information of the standby path, such as carrying the identifier of the standby path;

[0156] The protection type field is used to indicate the protection protocol type. Among them, protectiontype can define multiple flag bits to identify the protection protocol type, such as 1+1 protection or 1:1 protection, support for bidirectional switching or unidirectional switching, whether to delay backhaul, and the delay backhaul time, etc.

[0157] The field for the reason for requesting protection switching is used to indicate the reason for the tail node of the request message 1 to perform path switching;

[0158] The switched path field is used to indicate the path after switching based on the indication information. The tail node of message 1 can switch the service traffic to the switched path based on the switched path information. The switched path field may include multiple indication bits, for example, an indication bit for the primary path and an indication bit for the backup path. When the value of the indication bit for the primary path is a preset value (e.g., 1), it indicates that the switched path is the primary path. When the value of the indication bit for the backup path is the preset value, it indicates that the switched path is the backup path. For example: After the path PE2 - P1 - PE1 fails, in message 1 sent by PE1 to PE2 through the path PE1 - P2 - PE2, it includes Figure 3d the APS message shown, and at this time, the switched path indicated by the switched path field in this APS message may be, for example, the path PE2 - P2 - PE1.

[0159] S102: Communication device 1 sends message 1 to communication device 2.

[0160] After communication device 1 generates message 1, it can send message 1 to communication device 2. Corresponding to Figure 1b the scenario shown, communication device 1 can send message 1 to communication device 2 through the intermediate node P2.

[0161] S103: Communication device 2 obtains the APS message 1 from message 1.

[0162] After communication device 2 receives message 1, it parses message 1 and determines that message 1 includes APS message 1 based on indication information 1, thereby obtaining the APS message 1. In one example, after communication device 2 receives APS message 1, it can perform corresponding operations based on the APS message 1.

[0163] In one example, if APS message 1 does not request communication device 2 to perform path switching, communication device 2 can, for example, discard message 1.

[0164] In yet another example, after communication device 2 receives message 1, if APS message 1 is used to indicate that the tail node of path 1 switches the traffic transmission path from path 2 to path 3, communication device 2 can perform corresponding processing measures based on the APS state machine maintained locally. In one example, communication device 2 can switch the traffic transmission path from path 2 to path 3.

[0165] In one implementation, if the structure of message 1 received by communication device 2 is as Figure 3a or Figure 3bAs shown, the communication device 2 can locally store the corresponding relationship as shown in Table 1 below. In Table 1, path segment a is the path segment identifier of Path 2, segment list 2 is the segment list corresponding to Path 2, and segment list 3 is the segment list corresponding to Path 3.

[0166] Table 1

[0167] Path segment identifier Segment list 1 Segment list 2 path segment a segment list 2 segment list 3

[0168] After the communication device 2 receives Message 1, according to the path segment a carried in Message 1 (such as the path segment 1 field shown in Figure 3a or the path segment 2 field shown in Figure 3b ), the corresponding relationship shown in Table 1 is found. The communication device 1 determines that the path indicated by segment list 2 fails. Therefore, the communication device 2 can determine the segment list for guiding message forwarding as segment list 3. For example, the segment list for guiding message forwarding is replaced from segment list 2 to segment list 3, so as to realize switching the traffic transmission path from Path 2 to Path 3. The above-mentioned Table 1 does not mean that the communication device 2 must store the above corresponding relationship in the form of a table locally. It is just to display the above corresponding relationship in the form of a table in the application document, which is more intuitive.

[0169] In another implementation manner, if the structure of the APS message in Message 1 received by the communication device 2 is as shown in Figure 3d the communication device 1 can determine the segment list corresponding to the switched path indicated by the switched path field in the APS message. Assume that before receiving Message 1, the segment list for guiding message forwarding is segment list 2, and the segment list corresponding to the switched path is segment list 3. Then the communication device 2 can replace the segment list for guiding message forwarding from segment list 2 with segment list 3, so as to realize switching the traffic transmission path from Path 2 to Path 3.

[0170] It should be noted that if the APS message 1 in message 1 is used to request the tail node of path 1 to switch the transmission path of at least one service transmitted on path 2 to path 3, when the communication device 2 switches the transmission path of the traffic, it can switch the transmission path of the at least one service from path 2 to path 3, and for the traffic of other services, the switch can be temporarily not performed.

[0171] Through the above S101 - S103, the tail node of path 1 can switch the transmission path of the traffic from path 2 to path 3. In this process, the intermediate nodes on path 2 do not need to calculate the backup path. The head node of path 2 locally stores the segment list of the backup path. Thus, it can be seen that using this solution can reduce the requirement for the data processing ability of the intermediate nodes of the path to be switched, that is, path 2, thereby reducing the deployment cost of the SRv6 network.

[0172] In order to enable the two-way service traffic to be transmitted on the working path at the same time, or the two-way service traffic to be transmitted on the protection path at the same time. In a possible implementation manner, in addition to the foregoing S101 - S103, method 100 may further include the following S104 - S106. Through S104 - S106, after the tail node of path 1 switches the transmission path of the traffic from path 2 to path 3, the head node of path 1 can also switch the transmission path of the traffic from path 4 to path 1.

[0173] S104: The communication device 2 generates message 2, and message 2 includes the APS message 2. Message 2 is an SRv6 message.

[0174] In an implementation manner, message 2 is also a protocol message. The APS message 2 is similar to the APS message 1 and belongs to a request type message. At this time, the structure of the APS message 2 can be as Figure 3a 、 3b or as shown in 3d. This APS message 2 is used to request the tail node of path 1 to switch the transmission path of the traffic from path 4 to path 1. Among them, path 4 is the reverse common path of path 2, and path 1 is the reverse common path of path 3. Before path 2 fails, the head node of path 1 sends service traffic to the tail node of path 1 through path 4, and the tail node of path 1 sends service traffic to the head node of path 1 through path 2.

[0175] When the structure of the APS message 2 is as Figure 3a shown, Figure 3aThe path segment 1 field shown is used to carry the path segment identifier 3, and the path segment identifier 3 can identify both path 3 and can also be used to identify path 4. In some examples, the path segment identifier 3 can also be used to identify the transmission of at least one service on path 4. When paths 1, 2, 3, and 4 use the same path segment identifier, the path segment identifier 3 can be the same as the path segment identifier 1 mentioned above. Among them, path 3 is the transmission path of message 2.

[0176] When the structure of APS message 2 is as Figure 3b shown, Figure 3b the path segment 1 field shown is used to carry the aforementioned path segment identifier 3, and the path segment identifier 3 can identify path 3, and path 3 is the transmission path of message 2. Figure 3b The path segment 2 field shown is used to carry the path segment identifier 4, and the path segment identifier 4 is used to identify path 4. In some examples, the path segment identifier 4 can also be used to identify the transmission of at least one service on path 4. When paths 1 and 4 use the same path segment identifier, the path segment identifier 4 can be the same as the path segment identifier 1 mentioned above. When paths 2 and 3 use the same path segment identifier, the path segment identifier 3 and the aforementioned path segment identifier 2 can be the same.

[0177] When the structure of APS message 2 is as Figure 3d shown, Figure 3d the path indicated by the switched path field shown is path 1.

[0178] In another implementation, the APS message 2 can be a response message to the APS message 1. For this case, in one example, the structure of the APS message 2 can be as Figure 3a shown. At this time, the request type field of the APS message 2 can indicate that the APS message 2 is a response message, for example. In one example, the values of other fields in the APS message 2 except the request type field can be default, or can be the same as the values of the corresponding fields in the APS message 1, to indicate that the APS message 2 is a response message to the APS message 1.

[0179] S105: The communication device 2 sends message 2 to the communication device 1.

[0180] After the communication device 2 generates message 2, it can send message 2 to the communication device 1 through path 3.

[0181] S106: The communication device 1 obtains the APS message 2 from the message 2.

[0182] After the communication device 1 receives the message 2, it can parse the message 2 to obtain the APS message 2. Further, the communication device 1 can perform corresponding operations based on the APS message 2.

[0183] After the communication device 1 receives the message 2, if the APS message 2 is used to instruct the head node of path 1 to switch the traffic transmission path from path 4 to path 1, the communication device 1 can perform corresponding processing measures based on the APS state machine maintained locally. In one example, the communication device 1 can switch the traffic transmission path from path 4 to path 1.

[0184] In one implementation, if the structure of the message 2 received by the communication device 1 is as Figure 3a or Figure 3b shown, the communication device 1 can locally store the corresponding relationship shown in Table 2 below. In Table 2, path segment b is the path segment identifier of path 4, segment list 4 is the segment list corresponding to path 4, and segment list 1 is the segment list corresponding to path 1.

[0185] Table 2

[0186] Path segment identifier Segment list 1 Segment list 2 path segment b segment list 4 segment list 1

[0187] After the communication device 1 receives the message 2, according to the path segment b carried in the message 2 (such as Figure 3a the path segment 1 field shown or Figure 3b the path segment 2 field shown), it looks up the corresponding relationship shown in Table 2 and determines the segment list for guiding message forwarding as segment list 1. For example, it replaces the segment list for guiding message forwarding from segment list 4 with segment list 1, thereby realizing the switch of the traffic transmission path from path 4 to path 1.

[0188] In yet another implementation, if the structure of the APS message in the message 2 received by the communication device 1 is as Figure 3dAs shown, the communication device 2 can determine the segment list corresponding to the switched path indicated by the switched path field in the APS message. Assume that before receiving packet 2, the segment list guiding packet forwarding is segment list 4, and the segment list corresponding to the switched path is segment list 1. Then the communication device 1 can determine the segment list guiding packet forwarding as segment list 1, thereby realizing the switching of the traffic transmission path from path 4 to path 1.

[0189] In one example, when the communication device 1 switches the traffic transmission path, it can switch the transmission paths of the at least one service from path 4 to path 1. For the traffic of other services, the switching can be temporarily not performed.

[0190] As mentioned above, the associated channel can provide a control channel. Through an associated channel, different types of control channels can be provided, and one of the control channels is the APS channel. Regarding the other types of control channels that the associated channel can provide, it should be noted that:

[0191] The at least one control channel carried by the management channel can, for example, also include one or more of an operation administration maintenance (OAM) channel, a fault indication channel, a resource management channel, a signaling communication channel (SCC), and a management communication channel (MCC).

[0192] Among them:

[0193] The control and management messages carried by the OAM channel can be OAM messages. The OAM messages are the general term for a series of messages for implementing operation, maintenance, and management of a certain end-to-end SRv6 path. The OAM messages include, but are not limited to, connectivity detection messages, customer signal fault indication messages, unidirectional / bidirectional packet loss measurement messages, unidirectional / bidirectional delay measurement messages, and link loopback messages, etc. Among them: The connectivity detection message is used to implement the connectivity detection of the IPv6 path; the customer signal fault indication message is used to detect whether there is a customer signal fault in the IPv6 path; the unidirectional / bidirectional packet loss measurement message is used to detect the unidirectional / bidirectional packet loss of the SRv6 path; the unidirectional / bidirectional delay measurement message is used to detect the unidirectional / bidirectional delay of the IPv6 path; the link loopback message is used to implement the loopback detection of the IPv6 path. As an example, when the OAM message is a connectivity detection message, the OAM channel corresponds to the connectivity detection channel.

[0194] Regarding the format of the OAM message, the embodiments of the present application do not make any limitations, as long as the message can implement the corresponding OAM detection function.

[0195] The control and management message carried by the fault indication channel can be, for example, a fault indication message. The control and management message carried by the fault indication channel is used to record the fault indication information of a certain path. When the fault indication channel is included in Packet 1, the control and management message carried by the fault indication channel is used to record the fault indication information of Path 1.

[0196] In one example, the fault indication message may include one or more types of fault indication information. For example, it may include forward fault indication information and / or backward fault indication information. Among them, the forward fault indication information is used to indicate that there is a fault in an upstream node of a certain communication device on the transmission path of the message 1. For example, it is used to indicate that there is a fault in a certain intermediate node on the transmission path of the message 1. The upstream node fault mentioned here may be, for example, that the bit error rate of the upstream node is higher than a certain threshold, or that the packet loss rate of the upstream node is higher than a certain threshold, which is not limited here. The backward fault indication information is used to indicate that there is a fault in a downstream node of a certain communication device on the transmission path of the message 1. For example, it indicates that there is a fault in the tail node on the transmission path of the message 1. Similarly, the downstream node fault mentioned here may be, for example, that the bit error rate of the downstream node is higher than a certain threshold, or that the packet loss rate of the downstream node is higher than a certain threshold, which is not limited here. In yet another example, the fault indication information may, for example, reflect the fault status of path 1. For example, the fault indication information includes one or more of the following: signal failure (SF), signal degradation (SD), bit error rate higher than a certain threshold, packet loss rate higher than a certain threshold, and time delay higher than a certain threshold. At this time, the control and management message carried by the fault indication channel may include indication bits corresponding to various fault indication information. In another implementation manner, the fault indication information may be, for example, information such as the bit error rate and packet loss rate of the nodes on path 1. At this time, the control and management message carried by the fault indication channel may include, for example, the specific value of the bit error rate and / or the specific value of the packet loss rate. Optionally, the fault indication message may further include the identifier of path 1.

[0197] The embodiments of the present application do not make specific limitations on the structure of the fault indication message.

[0198] In one example, when the channel type field in the association channel indicates a fault indication channel, the value field of the TLV field carrying the association channel includes a fault indication message. For example, in Figure 3c-1 , the channel type field 302 is used to indicate a fault indication channel, and the value field 303 is used to carry the fault indication message. Another example is in Figure 3c-2 , the channel type field 304 is used to indicate a fault indication channel, and the value field 305 is used to carry the fault indication message.

[0199] In yet another example, the fault indication message is carried in a TLV field. The TLV field mentioned here can be carried in Figure 3c-1In the value field 303 of the TLV field shown, it can also be carried in Figure 3c-2 the value field 303 or 305 of the TLV field shown.

[0200] In addition, in another example, the fault indication message can include multiple types of messages. For example, it can include a link status indication message and a link parameter indication message. Among them, the link status indication message can include one or more of the following fault indication information: SF, SD, bit error rate higher than a certain threshold, packet loss rate higher than a certain threshold, and latency higher than a certain threshold, etc.; the link parameter indication message can include information such as bit error rate and packet loss rate.

[0201] The control management message carried by the resource management channel is used to implement resource management for a certain path. For this case, when the resource management channel is included in Packet 1, the control management message carried by the resource management channel is used to implement resource management for Path 1.

[0202] The control management message carried by the resource management channel can be, for example, a resource management message. The resource management message can include multiple types of messages. In one example, the resource management message can include a resource reservation request message, which is used to instruct the nodes on Path 1 to reserve resources. For example, SLA information such as bandwidth and latency can be carried in the resource reservation request message. In another example, the resource management message can include a resource status update message, which is used to collect the available resources of the nodes on Path 1. For example, collect resource information such as the bandwidth, cache, and latency that can be provided by the nodes on Path 1. In another example, the resource management message can include a resource reservation cancellation message, which is used to cancel a certain resource reservation request.

[0203] It should be noted that the resource management message in the embodiments of the present application can be, for example, a Resource ReSerVation Protocol (RSVP) message, such as the RSVP message mentioned in request for comments (RFC) 3209, or a message obtained by correspondingly expanding the RSVP message mentioned in, and the embodiments of the present application do not make specific limitations.

[0204] SCC is used to provide a separate channel between two nodes of the SRv6 path to transmit SCC messages, and the SCC messages are used to transmit control information.

[0205] MCC is used to provide a separate channel between two nodes of the SRv6 path to transmit MCC messages, and the MCC messages are used to transmit management information.

[0206] Regarding MCC and SCC, it should be noted that in a traditional SRv6 network, there is no separate channel between any two nodes to transmit management information, nor is there a separate channel to transmit control information. A separate control and management mechanism is required to achieve the transmission of management messages and control messages. MCC achieves the effect of transmitting management messages without using a separate control and management mechanism, and SCC achieves the effect of transmitting control messages without using a separate control and management mechanism.

[0207] Regarding the specific formats of SCC messages and MCC messages, the embodiments of this application do not make specific limitations. In one example, the formats of SCC messages and MCC messages can refer to the relevant description part in RFC5718, which will not be elaborated here.

[0208] Using an associated channel to carry different types of control channels has the following advantages:

[0209] 1. Using an associated channel to carry control and management messages of multiple protocols can reduce the number of control and management information packets transmitted between nodes by carrying multiple TLV fields in one packet.

[0210] 2. The associated channel can be carried by a common TLV field. By performing TLV encapsulation in the IPv6 extension header, other network layers such as UDP are removed, unifying and simplifying the packet encapsulation and transmission methods of control and management messages, and reducing device maintenance parameters such as UDP port number entries.

[0211] 3. It can support the extended use of the TLV format with variable value length to transmit control and management messages, and can carry more channel maintenance information.

[0212] 4. Using the IPv6 packet header for message transmission makes it possible to perform fast-channel processing on the packet header content at the device forwarding plane, improving message processing efficiency.

[0213] 5. Since the associated channel can be carried in multiple extension headers of IPv6, such as carried in the HBH option header or DOH, it can be applied not only to SRv6 nodes but also to IPv6 nodes that do not support SR.

[0214] In addition, existing IP layer protocols do not support MCC and SCC. Moreover, although ICMPv6 can indicate diagnostic information such as path connectivity and reachability, it cannot indicate node or network fault information. The BFD diagnostic word can indicate the reason for the last state change of the BFD session on the node, that is, it indicates the change in the control plane protocol state of the BFD protocol, and it also cannot indicate node or network fault information. However, the above-mentioned associated channel can support functions such as MCC, SCC, and indicating node or network fault information. When a node needs to support a new upper-layer protocol, it can carry the control and management information required by the upper-layer protocol through the associated channel, without the need to redesign a new upper-layer protocol, which has good protocol scalability and reduces the number of node protocols and maintenance complexity.

[0215] Moreover, in scenarios of convergence of multiple different types of networks, the associated channel carries various types of control and management messages in the IP extension header, simplifies the protocol stack without adding other layer protocols, reduces the implementation complexity of nodes, and increases the deployability in industrial scenarios.

[0216] The inventors of the present application found that for a Multi-Protocol Label Switching (MPLS) network applying SR, a fast rerouting mechanism is usually adopted to protect against link or node failures. Therefore, there are also the aforementioned problems that intermediate nodes need to maintain a large amount of path state information and path configuration information, and it is impossible to ensure that the forward and reverse paths of forward and reverse services pass through the same set of intermediate nodes and links.

[0217] If a failure occurs in the first path in the MPLS network, it will cause the service traffic originally transmitted through the first path to be unable to be transmitted normally, affecting the service quality. Currently, the path switching method in the MPLS network is similar to that in the SRv6 network, that is: if a failure occurs in the first path, each intermediate node on the first path needs to participate in the calculation of the backup path and locally maintain a large amount of path state information and path configuration information to switch the service traffic originally transmitted on the first path to the backup path for forwarding. This method requires intermediate nodes to have high data processing capabilities. Therefore, if this method is used to implement the protection switching of the first path, it will result in a relatively high deployment cost for the MPLS network.

[0218] In view of this, the embodiments of the present application provide a protection switching method. It can perform protection switching on the end-to-end MPLS path without requiring intermediate nodes to have high data processing capabilities. Among them, the network architecture of a typical MPLS network applying SR can also be as Figure 1b shown. In other words, in another example, Figure 1bThe network 100 shown can be an MPLS network applying SR. At this time, PE1, P1, P2, and PE2 are all nodes in the MPLS network. Regarding Figure 1b the network architecture shown, it will not be repeated here.

[0219] In one example, Figure 1b the path PE1 - P2 - PE2 shown is called path 1, the path PE2 - P1 - PE1 is called path 2, the path PE2 - P2 - PE1 is called path 3, and the path PE1 - P1 - PE2 is called path 4. In one example:

[0220] The tail node of path 1 can, after path 2 fails, switch the sending path of the forward service traffic of the tail node of path 1 from path 2 to path 3, and send the forward service traffic through path 3. In the SRv6 packet sent through path 3, it includes the MPLS label list indicating path 3 mentioned above. Correspondingly, the head node of path 1 can switch the path for receiving the forward service traffic from path 2 to path 3, and receive the forward service traffic from path 3. For ease of description, the tail node of path 1 is called the first node, and the head node of path 1 is called the second node. Then, the forward service traffic of the first node refers to the service traffic sent from the first node to the second node, and the reverse service traffic of the first node refers to the service traffic sent from the second node to the first node.

[0221] In addition, to ensure that the forward and reverse paths of the forward and reverse services pass through the same set of intermediate nodes and links. In an optional manner, after the tail node of path 1 switches the traffic to path 3, the head node of path 1 can switch the path for sending service traffic from path 4 to path 1, and send the service traffic through path 1. It can be understood that in the MPLS packet sent through path 1, it includes the MPLS label list indicating path 1 mentioned above. Correspondingly, the tail node of path 1 can switch the path for receiving the service traffic sent by the head node of path 1 from path 4 to path 1, and receive the service traffic sent by the head node of path 1 from path 4. In other words, the tail node of path 1 can switch the receiving path of its own reverse service traffic from path 4 to path 1, and receive the reverse service traffic through path 1. Among them, the reverse service traffic of the tail node of path 1 refers to the service traffic sent from the head node of path 1 to the tail node of path 1.

[0222] It can be understood that the above-mentioned path 1 and path 3 are reverse common path paths, and path 2 and path 4 are reverse common path paths. Using this solution, after path 2 fails, the service traffic originally transmitted on path 2 can be switched to path 3 for transmission, and the service traffic originally transmitted on path 4 can be switched to path 1 for transmission, so that the two-way service traffic is transmitted on the protection path, facilitating the management of service traffic.

[0223] Currently, MPLS does not define how to transmit linear protection switching messages on the data plane, and this application provides a protection switching method that can implement the transmission of protection switching messages on the data plane in an MPLS network.

[0224] See Figure 4 , which is a signaling interaction diagram of a protection switching method provided by an embodiment of this application. Figure 4 The method 200 shown, for example, may include the following S201-S206.

[0225] S201: Communication device 1 generates message 1, and message 1 includes APS message 1. Message 1 is an MPLS message.

[0226] In an embodiment of this application, message 1 is a protocol message, and APS message 1 can be carried in the protocol payload of message 1.

[0227] In an example, in addition to including APS message 1, message 1 may further include indication information 1, and indication information 1 is used to indicate APS message 1. In an example, indication information 1 is carried in the label stack of message 1.

[0228] In one implementation, indication information 1 may be path identifier 1, and path identifier 1 is used to identify path 1.

[0229] In one implementation, considering that for an MPLS message, in addition to the MPLS label (label) that guides message forwarding, its label stack may further include a path segment field. Among them, the path segment field value is used to identify an MPLS path. When message 1 includes a path segment field, the value of this path segment field is used to identify the transmission path of message 1, for example, it can be used to identify the list of MPLS labels for guiding the forwarding of message 1. In an example, the aforementioned path identifier 1 may be path segment identifier 1, and the path segment identifier 1 mentioned here can be used to identify path 1. In the following description, it is assumed that path identifier 1 is path segment identifier 1 for illustration.

[0230] The communication device 1 can locally maintain an APS state machine, which is used to process APS messages. The communication device 1 can periodically generate a packet including an APS message according to the local state machine and send the packet including the APS message.

[0231] In the embodiment of the present application, the transmission path of the packet 1 is path 1.

[0232] In an example, if the path with the node corresponding to the communication device 2 as the head node and the node corresponding to the communication device 1 as the tail node does not fail, the APS message 1 may not request the node corresponding to the communication device 2 to perform path switching.

[0233] In another example, the communication device 1 can generate the packet 1 after path 2 fails. Wherein: the head node of path 2 is the node corresponding to the communication device 2, and the tail node of path 2 is the node corresponding to the communication device 1. In other words, the communication device 1 can generate the packet 1 after the path with the tail node of path 1 as the head node and the head node of path 1 as the tail node fails. For this case, the APS message 1 is used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3, where path 2 and path 3 have the same head node and tail node. Path 3 can be regarded as a backup path of path 2. Wherein: path 1 can correspond to Figure 1b PE1-P2-PE2 in Figure 1b path 2 can correspond to Figure 1b PE2-P1-PE1 in

[0234] As described above, the communication device 1 can generate the packet 1 after path 2 fails. At this time, the APS message 1 is used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3. For this case, the packet 1 may also carry the identifier of the path to be switched (i.e., path 2), so that the APS message 1 can be used to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3.

[0235] In one implementation, for the 1:1 protection switching scenario or the 1+1 protection switching scenario, the identifier of path 2 and the identifier of path 1 can be the same identifier. For this case, the path segment identifier 1, which is the foregoing indication information 1, can also be used to identify path 2. In this way, in the packet 1, a path segment field can be used to indicate the APS message 1 and to request the tail node of path 1 to switch the traffic transmission path from path 2 to path 3. For this case, the packet structure of the packet 1 can refer to Figure 5a as shown.Figure 5a This is a schematic structural diagram of a message 1 provided by an embodiment of the present application.

[0236] In Figure 5a :

[0237] The path segment 1 field is used to carry the aforementioned path segment identifier 1;

[0238] The APS message 1 can correspond to Figure 5a the shaded part shown. Regarding each field in the APS message 1, reference can be made to the relevant description in Request for Comments (RFC) 7271, which will not be elaborated here.

[0239] In one example, the APS message 1 can be carried in an associated channel (ACH). For this case, the ACH can include an ACH header, and the ACH header includes indication information indicating that the associated channel carries the APS message 1. For this case, Figure 5a between the APS message 1 and the path segment 1 shown, an associated channel (ACH) header can also be included. At this time, the structure of the message 1 can be as Figure 5b shown, Figure 5b Both the ACH header and the APS message 1 shown are the content carried by the ACH. For this case, the path segment identifier 1 is used to identify that the message 1 includes an ACH, and the ACH header of the ACH can indicate that the ACH carries the APS message 1.

[0240] It should be noted that Figure 5a and Figure 5b are only shown as an example and do not limit the embodiments of the present application. For example, in some embodiments, in addition to including Figure 5a and Figure 5b the fields shown, the message 1 can also include other fields, which will not be elaborated one by one here.

[0241] It should be noted that for the 1:1 protection switching scenario or the 1+1 protection switching scenario, the aforementioned path segment identifier 1, in addition to being able to identify path 1 and path 2, can also identify path 3 and path 4. The path 4 mentioned here is the backup path of path 1. In other words, path 1 and path 4 have the same head node and tail node. For example, for the Figure 1b shown PE1-P2-PE2 corresponding to path 1, path 4 corresponds to Figure 1b the shown PE1-P1-PE2.

[0242] In some embodiments, considering that path 2 can be used to transmit multiple types of traffic, and different types of traffic may have different requirements for quality of service. To best meet the quality of service requirements of traffic with high quality of service requirements, in one example, after path 2 fails, the transmission path of traffic with high quality of service requirements can be preferentially switched from path 2 to path 3. For this case, the message 1 can also carry the identifier of at least one service transmitted on path 2, so that the APS message 1 can be used to request the tail node of path 1 to switch the transmission path of the at least one service from path 2 to path 3.

[0243] In one example, the identifier of the at least one service can be carried by the path segment identifier 1. For example, the identifier of the at least one service can be carried by a part of the bits in the path segment identifier 1. At this time, the path segment identifier 1 can not only be used to indicate the APS message 1, but also be used to identify path 2 and identify at least one service transmitted on path 2. The at least one service mentioned here can be, for example, the aforementioned traffic with high quality of service requirements.

[0244] In another example, the identifier of the at least one service can be carried by other fields. For example, for Figure 5a the message 1 shown, a field can be added after the APS message 1 to carry the identifier of the at least one service.

[0245] In another implementation, the identifier of path 2 and the identifier of path 1 can be different identifiers. For this case, the message 1 can also include a path identifier 2, and the path segment identifier 2 is used to identify path 2. In one example, the path identifier 2 can be the path segment identifier 2. For this case, the node receiving the message 1 can determine based on the path segment identifier 2 that the APS message 1 is used to request the tail node of path 1 to switch the transmission path of the traffic from path 2 to path 3. For this case, the message structure of the message 1 can refer to Figure 5c shown. Figure 5c A schematic diagram of the structure of a message 1 provided by an embodiment of the present application.

[0246] In Figure 5c :

[0247] The path segment 1 field is used to carry the aforementioned path segment identifier 1;

[0248] The path segment 2 field is used to carry the aforementioned path segment identifier 2;

[0249] The APS message 1 can correspond to Figure 5cFor the shaded part shown, regarding each field in the APS message 1, reference can be made to the relevant description in RFC 7271, which will not be elaborated here.

[0250] In one example, the APS message 1 can be carried in the ACH. For this case, the ACH header of the ACH includes indication information indicating that the associated channel carries the APS message 1. For this case, Figure 5c Between the APS message 1 and the path segment 1 shown, an ACH header can also be included. At this time, the structure of the message 1 can refer to Figure 5d shown Figure 5d Both the ACH header and the APS message 1 shown are the contents carried by the ACH. For this case, the path segment identifier 1 is used to identify that the message 1 includes an ACH, and the ACH header of the ACH can indicate that the ACH carries the APS message 1.

[0251] It should be noted that Figure 5c and Figure 5d are only shown as an example and do not constitute a limitation on the embodiments of the present application. In some embodiments, in addition to including Figure 5c and Figure 5d the fields shown, the message 1 can also include other fields, which will not be elaborated one by one here.

[0252] It should be noted that for the 1:1 protection switching scenario or the 1+1 protection switching scenario, in addition to being able to be used to identify path 1, the aforementioned path segment identifier 1 can also identify path 4. The path 4 mentioned here is the backup path of path 1. In other words, path 1 and path 4 have the same head node and tail node. For example, for Figure 1b the PE1-P2-PE2 shown corresponding to path 1, path 4 corresponds to Figure 1b the PE1-P1-PE2 shown. The aforementioned path segment identifier 2, in addition to being able to be used to identify path 2, can also identify path 3. Of course, the path segment identifier of path 4 and the path segment identifier of path 1 can also be different, and the path segment identifier of path 3 and the path segment identifier of path 2 can also be different. The embodiments of the present application do not make specific limitations. For the 1:n protection switching scenario, the path segment identifier corresponds one-to-one to the path it identifies.

[0253] As described above, considering that Path 2 can be used to transmit multiple types of traffic, and different types of traffic may have different requirements for quality of service. To best meet the quality of service requirements of traffic with high quality of service requirements, in one example, after a failure occurs in Path 2, the transmission path of traffic with high quality of service requirements can be preferentially switched from Path 2 to Path 3. For this scenario, the message 1 can also carry the identifier of at least one service transmitted on Path 2, so that the APS message 1 can be used to request the tail node of Path 1 to switch the transmission path of the at least one service from Path 2 to Path 3.

[0254] In one example, the identifier of the at least one service can be carried by the path segment identifier 2. For example, the identifier of the at least one service can be carried by a part of the bits in the path segment identifier 2. At this time, the path segment identifier 2 can be used not only to identify Path 2, but also to identify at least one service transmitted on Path 2. The at least one service mentioned here can be, for example, the traffic with high quality of service requirements described above.

[0255] In another example, the identifier of the at least one service can be carried by other fields. For example, for Figure 5c and Figure 5d the message 1 shown, a field can be added after the APS message 1, for example, after the path segment 2 field, to carry the identifier of the at least one service.

[0256] S202: The communication device 1 sends the message 1 to the communication device 2.

[0257] After generating the message 1, the communication device 1 can send the message 1 to the communication device 2. Corresponding to Figure 1b the scenario shown, the communication device 1 can send the message 1 to the communication device 2 via the intermediate node P2.

[0258] S203: The communication device 2 obtains the APS message 1 from the message 1.

[0259] After receiving the message 1, the communication device 2 can parse the message 1, determine that the message 1 includes the APS message 1 based on the indication information 1, and further obtain the APS message 1 from the message 1. In one example, after receiving the APS message 1, the communication device 2 can perform corresponding operations based on the APS message 1.

[0260] In one example, if the APS message 1 is used to instruct the tail node of Path 1 to switch the transmission path of the traffic from Path 2 to Path 3, the communication device 2 can switch the transmission path of the traffic from Path 2 to Path 3.

[0261] For the specific implementation of S203, please refer to the relevant description of S103 above, and the description will not be repeated here. The difference between S203 and S103 is that in S103, what guides the forwarding of the message is the segment list, that is, the SRv6 message is encapsulated with the segment list that guides the forwarding of the message; while in S203, what guides the forwarding of the message is the MPLS label list, that is, the MPLS message is encapsulated with the MPLS label list that guides the forwarding of the message. Accordingly, in S203, the corresponding relationship stored in the communication device 2 does not include the segment list shown in Table 1, but includes the MPLS label list.

[0262] Through the above S201-S203, the tail node of path 1 can switch the transmission path of the traffic from path 2 to path 3. In this process, the intermediate nodes on path 2 do not need to maintain a large amount of path state information and path configuration information. The head node of path 2 locally stores the MPLS label list of the backup path. It can be seen that by using this solution, the requirements for data processing capabilities of the intermediate nodes of the path to be switched, i.e. path 2, can be reduced, thereby reducing the deployment cost of the MPLS network.

[0263] In a possible implementation, in addition to the aforementioned S201-S203, method 200 may also include the following S204-S206. Through S204-S206, after the tail node of path 1 switches the transmission path of the traffic from path 2 to path 3, the head node of path 1 can also switch the transmission path of the traffic from path 4 to path 1.

[0264] S204: Communication device 2 generates message 2, message 2 includes APS message 2, and message 2 is an MPLS message.

[0265] In one implementation, message 2 is also a protocol message. The APS message 2 is similar to the APS message 1 and is a request message. In this case, the structure of the APS message 2 can be as follows: Figure 5a or 5b or Figure 5c or Figure 5d The APS message 2 is used to request the tail node of path 1 to switch the transmission path of the traffic from path 4 to path 1. Path 4 is the reverse common path of path 2, and path 1 is the reverse common path of path 3.

[0266] When the structure of APS message 2 is as follows Figure 5a or Figure 5b When shown, Figure 5a or Figure 5bThe path segment 1 field shown is used to carry the aforementioned path segment identifier 3. The path segment identifier 3 can identify path 3 and can also be used to identify path 4. In some examples, the path segment identifier 3 can also be used to identify the transmission of at least one service on path 4. When paths 1, 2, 3, and 4 use the same path segment identifier, the path segment identifier 3 can be the same as the path segment identifier 1 mentioned in S201. Among them, path 3 is the transmission path of message 2.

[0267] When the structure of APS message 2 is as Figure 5c or Figure 5d shown, Figure 5c or Figure 5d the path segment 1 field shown is used to carry the aforementioned path segment identifier 3. The path segment identifier 3 can identify path 3, and path 3 is the transmission path of message 2. Figure 5c or Figure 5d the path segment 2 field shown is used to carry path segment identifier 4. The path segment identifier 4 is used to identify path 4. In some examples, the path segment identifier 4 can also be used to identify the transmission of at least one service on path 4. When paths 1 and 4 use the same path segment identifier, the path segment identifier 4 can be the same as the path segment identifier 1 mentioned in S201. When paths 2 and 3 use the same path segment identifier, the path segment identifier 3 can be the same as the path segment identifier 2 mentioned in S201.

[0268] In another implementation, APS message 2 can be an acknowledgment message of APS message 1. For this case, in one example, the structure of APS message 2 can be as Figure 5a shown. At this time, the request type field of APS message 2 can indicate that this APS message 2 is an acknowledgment message. In one example, the values of other fields in APS message 2 except the request type field can be default, or can be the same as the values of the corresponding fields in APS message 1, to indicate that APS message 2 is an acknowledgment message of APS message 1.

[0269] S205: The communication device sends message 2 to communication device 1.

[0270] After the communication device 2 generates message 2, it can send message 2 to communication device 1 through path 3.

[0271] S206: The communication device 1 obtains the APS message 2 from the message 2.

[0272] After the communication device 1 receives the message 2, it can parse the message 2 to obtain the APS message 2. Further, the communication device 1 can perform corresponding operations based on the APS message 2.

[0273] After the communication device 1 receives the message 2, if the APS message 2 is used to instruct the head node of path 1 to switch the traffic transmission path from path 4 to path 1, the communication device 1 can perform corresponding processing measures based on the APS state machine maintained locally. In one example, the communication device 1 can switch the traffic transmission path from path 4 to path 1.

[0274] For the specific implementation of S206, reference can be made to the relevant description part of S106 above, which will not be repeated here. The difference between S206 and S106 is that in S106, the segment list is used to guide message forwarding, that is, the segment list for guiding message forwarding is encapsulated in the SRv6 message; while in S206, the MPLS label list is used to guide message forwarding, that is, the MPLS label list for guiding message forwarding is encapsulated in the MPLS message. Correspondingly, in the correspondence relationship saved in the communication device 1 in S206, instead of including the segment list shown in Table 2, it includes the MPLS label list.

[0275] From the above method 100 and method 200, it can be seen that whether in the SRv6 network or in the MPLS network applying SR, the path identifier can be used to indicate the protection switching message. In some embodiments, in the SRv6 network, the path segment identifier indicating the segment list can be used to indicate the protection switching message, and in the MPLS network applying SR, the path segment identifier indicating the MPLS label list can be used to indicate the protection switching message. In this way, the node receiving the message carrying the path segment identifier can determine that the received message includes the protection switching message according to the path segment identifier, and further process the protection switching message.

[0276] The embodiment of the present application also provides a protection switching method, see Figure 6 , which is a schematic flowchart of a protection switching method provided by the embodiment of the present application. Figure 6 The protection switching method 300 shown, for example, may include the following S301 - S302.

[0277] The method 300, for example, can be applied to the above method 100. When the method 300 is applied to the above method 100, the method 300, for example, can correspond to the steps executed by the communication device 1 in the above method 100. Or, corresponding to the above method 100, the steps executed by the intermediate node on path 1.

[0278] S301: Obtain a first Segment Routing for Internet Protocol version 6 (SRv6) packet, where the first SRv6 packet includes a first protection switching message.

[0279] S302: Send the first SRv6 packet to the tail node of the first path, where the first path is the path used to forward the first SRv6 packet.

[0280] The first SRv6 packet mentioned here may correspond to packet 1 in method 100, and the first protection switching message mentioned here may correspond to APS message 1 in method 100.

[0281] In one implementation, the first protection switching message is carried in an extension header of the first SRv6 packet, and the extension header is:

[0282] A Hop-by-Hop (HBH) option header, or, a Destination Option (DOH) header, or, a Segment Routing Header (SRH).

[0283] In one implementation, the first SRv6 packet includes first indication information for indicating the first protection switching message.

[0284] In one implementation, the first indication information is a first path identifier for identifying the first path.

[0285] The first path mentioned here may correspond to path 1 in method 100, and the first path identifier mentioned here may correspond to path identifier 1 in method 100.

[0286] In one implementation, the first path identifier is further used to identify a second path, and the first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to a third path, where the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path.

[0287] The second path mentioned here may correspond to path 2 in method 100.

[0288] In one implementation, the first path identifier is further used to identify at least one service transmitted on the second path, and the first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path, including:

[0289] The first protection switching message is used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

[0290] The third path mentioned herein may be, for example, path 3 in method 100.

[0291] In one implementation, the first path is identified as:

[0292] First path segment identifier.

[0293] The first path segment identifier mentioned herein may correspond to path segment identifier 1 in method 100.

[0294] In one implementation, the first SRv6 packet further includes a second path identifier for identifying a second path. The first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path, where the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path.

[0295] The second path identifier mentioned herein may correspond to path identifier 2 in method 100. The second path mentioned herein may be, for example, path 2 in method 100, and the third path mentioned herein may be, for example, path 3 in method 100.

[0296] In one implementation, the second path identifier is further used to identify at least one service transmitted on the second path. The first protection switching message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path, including:

[0297] The first protection switching message is used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

[0298] In one implementation, the second path is identified as:

[0299] Second path segment identifier.

[0300] The second path segment identifier mentioned herein may correspond to path segment identifier 2 in method 100.

[0301] In one implementation, the method further includes:

[0302] Receiving a second SRv6 packet through the third path, where the second SRv6 packet includes a second protection switching message, and the second protection switching message is a response message to the first protection switching message.

[0303] The second SRv6 packet mentioned herein may correspond to packet 2 in method 100, and the second protection switching message mentioned herein may correspond to APS message 2 in method 100.

[0304] In one implementation, a first type length value TLV is included in the extension header of the first SRv6 packet, and the first TLV is used to carry the first indication information and the first protection switching message.

[0305] In one implementation, the first TLV is an associated channel TLV, the associated channel TLV includes a channel type field, the channel type field is used to carry the first indication information, and the value field of the associated channel TLV is used to carry the first protection switching message.

[0306] In one implementation, the first SRV6 packet includes an associated channel, the associated channel can carry different types of control channels, and one type of control channel is a protection switching channel, and the protection switching channel is used to carry the first indication information and the first protection switching message.

[0307] In one implementation, the first SRV6 packet includes second indication information, and the second indication information is used to indicate the associated channel.

[0308] The second indication information mentioned herein may correspond to indication information 2 in method 100.

[0309] In one implementation, the method further includes:

[0310] Receiving a second SRv6 packet sent by the tail node of the first path, where the second SRv6 packet includes a second protection switching message.

[0311] The second SRv6 packet mentioned herein may correspond to packet 2 in method 100, and the second protection switching message mentioned herein may correspond to APS message 2 in method 100.

[0312] For the specific implementation of the above method 300, reference may be made to the relevant description part of the above method 100, and the description will not be repeated here.

[0313] The embodiment of the present application further provides a protection switching method. Refer to Figure 7 , which is a schematic flowchart of a protection switching method provided by an embodiment of the present application. Figure 7 The protection switching method 400 shown may include, for example, the following S401-S402.

[0314] The method 400 can be applied to the above method 100, for example. When the method 400 is applied to the above method 100, the method 400 can correspond to the steps executed by the communication device 2 in the above method 100.

[0315] S401: Receive a first Segment Routing for IPv6 (SRv6) packet, where the first SRv6 packet includes a first Automatic Protection Switching (APS) message.

[0316] S402: Obtain the first APS message from the first SRv6 packet.

[0317] The first SRv6 packet mentioned here can correspond to packet 1 in method 100, and the first protection switching message mentioned here can correspond to APS message 1 in method 100.

[0318] In one implementation, the first APS message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path, where the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path, and the first path is the path for forwarding the first SRv6 packet.

[0319] The first path mentioned here can be, for example, path 1 in method 100, the second path mentioned here can be, for example, path 2 in method 100, and the third path mentioned here can be, for example, path 3 in method 100.

[0320] In one implementation, it further includes:

[0321] Based on the first APS message, switch the traffic transmission path from the second path to the third path.

[0322] In one implementation, the method further includes:

[0323] Send a second SRv6 packet to the head node of the first path through the third path, where the second SRv6 packet includes a second APS message, and the second APS message is a response message to the first APS message.

[0324] The second SRv6 packet mentioned here can correspond to packet 2 in method 100, and the second protection switching message mentioned here can correspond to APS message 2 in method 100.

[0325] Regarding the specific implementation of the above method 400, reference can be made to the relevant description part of the above method 100, which will not be repeated here.

[0326] The embodiments of the present application also provide a protection switching method. Refer to Figure 8 , which is a schematic flowchart of a protection switching method provided by the embodiments of the present application. Figure 8 The protection switching method 500 shown, for example, may include the following S501 - S502.

[0327] The method 500 may be executed by a first node, and the first node may correspond to the communication device 2 in the above method 100, for example. In one example, the method 500 may correspond to the steps executed by the communication device 2 in the above method 100.

[0328] S501: After a failure occurs in the first Segment Routing IPv6 (SRv6) path, switch the sending path of the forward service traffic of the first node from the first SRv6 path to a second SRv6 path. The forward service traffic is the service traffic sent by the first node to a second node. The first SRv6 path is the path between the first node and the second node. The first node is the head node of the first SRv6 path, and the second node is the tail node of the first SRv6 path. The first SRv6 path and the second SRv6 path have the same head node and tail node.

[0329] S502: Send the forward service traffic through the second SRv6 path.

[0330] The first SRv6 path mentioned here may correspond to path 2 in method 100, and the second SRv6 path mentioned here may correspond to path 3 in method 100. The second node mentioned here may correspond to the communication device 1 in method 100, for example.

[0331] In one implementation, after a failure occurs in the first SRv6 path, the method further includes:

[0332] Switch the receiving path of the reverse service traffic of the first node from a third SRv6 path to a fourth SRv6 path. The reverse service traffic is the traffic sent by the second node to the first node. The head node of the third SRv6 path is the second node, and the tail node of the third SRv6 path is the first node. The third SRv6 path and the fourth SRv6 path have the same head node and tail node;

[0333] Receive the reverse service traffic through the fourth SRv6 path.

[0334] The third SRv6 path mentioned here may correspond to path 4 in method 100, and the fourth SRv6 path mentioned here may correspond to path 1 in method 100.

[0335] In one implementation, the fourth SRv6 path and the second SRv6 path are two-way common path.

[0336] In one implementation, the first node stores a first segment list, which is used to describe a set of segment identifiers (SIDs) of the second SRv6 path.

[0337] The first segment list mentioned here can be, for example, the segment list 3 indicating path 3 in method 100.

[0338] In one implementation, before the first node switches the transmission path of the forward service traffic from the first SRv6 path to the second SRv6 path, the method further includes:

[0339] The first node receives a first Internet Protocol Version 6 Segment Routing (SRv6) packet sent by the second node, and the first SRv6 packet includes a first protection switching message;

[0340] Perform the path switching according to the first protection switching message.

[0341] The first SRv6 packet mentioned here can correspond to packet 1 in method 100, and the first protection switching message mentioned here can correspond to the APS message 1 in method 100.

[0342] In one implementation, the first SRv6 packet further includes first information, which is used to identify the first SRv6 path.

[0343] The first information mentioned here can be, for example, path identifier 1 or path identifier 2 in method 100. When path 1 and path 2 in method 100 use the same path identifier, the first information mentioned here can be, for example, path identifier 1 in method 100. When path 1 and path 2 in method 100 use different path identifiers, the first information mentioned here can be, for example, path identifier 2 in method 100.

[0344] In one implementation, the first node stores a first segment list, including:

[0345] The first node stores the correspondence between the first information and the first segment list.

[0346] In one implementation, sending the forward service traffic through the second SRv6 path includes:

[0347] Determine the first segment list according to the correspondence and the first information;

[0348] Encapsulate the forward service traffic using the first - segment list;

[0349] Send the forward service traffic through the second SRv6 path.

[0350] In one implementation, the first information includes:

[0351] The first path - segment identifier.

[0352] The first path - segment identifier mentioned this time can correspond to the path - segment identifier 1 in method 100.

[0353] For the specific implementation of the above method 500, reference can be made to the relevant description part of the above method 100, and it will not be repeated here.

[0354] In addition, an embodiment of the present application further provides a communication device 900, as shown in Figure 9 shown. Figure 9 It is a schematic structural diagram of a communication device provided by an embodiment of the present application. The communication device 900 includes a transceiver unit 901 and a processing unit 902. The communication device 900 can be used to execute method 100, method 200, method 300, method 400, or method 500 in the above embodiments.

[0355] In one example, the communication device 900 can execute method 100 in the above embodiments. When the communication device 900 is used to execute method 100 in the above embodiments: The transceiver unit 901 is used to perform the transceiver operations performed by communication device 1 in method 100 (in this application, the transceiver operation refers to operations related to receiving and / or sending). The processing unit 902 is used to perform the operations other than the transceiver operations performed by communication device 1 in method 100. For example, the processing unit 902 is used to generate message 1, where message 1 includes APS message 1, and message 1 is an SRv6 message; the transceiver unit 901 is used to send message 1 to communication device 2.

[0356] In one example, the communication device 900 can execute method 100 in the above embodiments. When the communication device 900 is used to execute method 100 in the above embodiments: The transceiver unit 901 is used to perform the transceiver operations performed by communication device 2 in method 100. The processing unit 902 is used to perform the operations other than the transceiver operations performed by communication device 2 in method 100. For example, the transceiver unit 901 is used to receive message 1, where message 1 includes APS message 1, and message 1 is an SRv6 message; the processing unit 902 is used to obtain APS message 1 from message 1.

[0357] In one example, the communication device 900 may execute the method 200 in the above embodiments. When the communication device 900 is used to execute the method 200 in the above embodiments: The transceiver unit 901 is used to execute the transceiver operations performed by the communication device 1 in the method 200. The processing unit 902 is used to execute the operations other than the transceiver operations performed by the communication device 1 in the method 200. For example, the processing unit 902 is used to generate a message 1, where the message 1 includes an APS message 1, and the message 1 is an MPLS message; the transceiver unit 901 is used to send the message 1 to the communication device 2.

[0358] In one example, the communication device 900 may execute the method 200 in the above embodiments. When the communication device 900 is used to execute the method 200 in the above embodiments: The transceiver unit 901 is used to execute the transceiver operations performed by the communication device 2 in the method 200. The processing unit 902 is used to execute the operations other than the transceiver operations performed by the communication device 2 in the method 200. For example, the transceiver unit 901 is used to receive a message 1, where the message 1 includes an APS message 1, and the message 1 is an MPLS message; the processing unit 902 is used to obtain the APS message 1 from the message 1.

[0359] In one example, the communication device 900 may execute the method 300 in the above embodiments. When the communication device 900 is used to execute the method 300 in the above embodiments: The transceiver unit 901 is used to execute the transceiver operations in the method 300. The processing unit 902 is used to execute the operations other than the transceiver operations in the method 300. For example, the processing unit 902 is used to obtain a first Segment Routing for IPv6 (SRv6) message, and the first SRv6 message includes a first protection switching message; the transceiver unit 901 is used to send the first SRv6 message to the tail node of the first path, and the first path is the path used to forward the first SRv6 message.

[0360] In one example, the communication device 900 may execute the method 400 in the above embodiments. When the communication device 900 is used to execute the method 400 in the above embodiments: The transceiver unit 901 is used to execute the transceiver operations in the method 400. The processing unit 902 is used to execute the operations other than the transceiver operations in the method 400. For example, the transceiver unit 901 is used to receive a first Segment Routing for IPv6 (SRv6) message, and the first SRv6 message includes a first Automatic Protection Switching (APS) message; the processing unit 902 is used to obtain the first APS message from the first SRv6 message.

[0361] In one example, the communication device 900 may execute the method 500 in the foregoing embodiments. When the communication device 900 is used to execute the method 500 in the foregoing embodiments: The transceiver unit 901 is used to execute the transceiver operations in the method 500. The processing unit 902 is used to execute the operations other than the transceiver operations in the method 500. For example, the processing unit 902 is used to switch the sending path of the forward service traffic of the first node from the first SRv6 path to the second SRv6 path after a failure occurs in the first Internet Protocol version 6 segment routing (SRv6) path. The forward service traffic is the service traffic sent from the first node to the second node. The first SRv6 path is the path between the first node and the second node. The first node is the head node of the first SRv6 path, and the second node is the tail node of the first SRv6 path. The first SRv6 path and the second SRv6 path have the same head node and tail node; the transceiver unit 901 is used to send the forward service traffic through the second SRv6 path.

[0362] In addition, an embodiment of the present application further provides a communication device 1000. Refer to Figure 10 as shown in Figure 10 a schematic structural diagram of a communication device provided by an embodiment of the present application. The communication device 1000 includes a communication interface 1001 and a processor 1002 connected to the communication interface 1001. The communication device 1000 can be used to execute the method 100, the method 200, the method 300, the method 400, or the method 500 in the foregoing embodiments.

[0363] In one example, the communication device 1000 may execute the method 100 in the foregoing embodiments. When the communication device 1000 is used to execute the method 100 in the foregoing embodiments: The communication interface 1001 is used to execute the transceiver operations performed by the communication device 1 in the method 100. The processor 1002 is used to execute the operations other than the transceiver operations performed by the communication device 1 in the method 100. For example, the processor 1002 is used to generate a message 1, and the message 1 includes an APS message 1. The message 1 is an SRv6 message; the communication interface 1001 is used to send the message 1 to the communication device 2.

[0364] In one example, the communication device 1000 may execute the method 100 in the foregoing embodiments. When the communication device 1000 is used to execute the method 100 in the foregoing embodiments: The communication interface 1001 is used to execute the transceiver operations performed by the communication device 2 in the method 100. The processor 1002 is used to execute the operations other than the transceiver operations performed by the communication device 2 in the method 100. For example, the communication interface 1001 is used to receive the message 1, and the message 1 includes an APS message 1. The message 1 is an SRv6 message; the processor 1002 is used to obtain the APS message 1 from the message 1.

[0365] In one example, the communication device 1000 may execute the method 200 in the foregoing embodiments. When the communication device 1000 is used to execute the method 200 in the foregoing embodiments: The communication interface 1001 is used to execute the transceiver operations performed by communication device 1 in method 200. The processor 1002 is used to execute the operations other than the transceiver operations performed by communication device 1 in method 200. For example, the processor 1002 is used to generate message 1, where message 1 includes APS message 1, and message 1 is an MPLS message; the communication interface 1001 is used to send message 1 to communication device 2.

[0366] In one example, the communication device 1000 may execute the method 200 in the foregoing embodiments. When the communication device 1000 is used to execute the method 200 in the foregoing embodiments: The communication interface 1001 is used to execute the transceiver operations performed by communication device 2 in method 200. The processor 1002 is used to execute the operations other than the transceiver operations performed by communication device 2 in method 200. For example, the communication interface 1001 is used to receive message 1, where message 1 includes APS message 1, and message 1 is an MPLS message; the processor 1002 is used to obtain APS message 1 from message 1.

[0367] In one example, the communication device 1000 may execute the method 300 in the foregoing embodiments. When the communication device 1000 is used to execute the method 300 in the foregoing embodiments: The communication interface 1001 is used to execute the transceiver operations in method 300. The processor 1002 is used to execute the operations other than the transceiver operations in method 300. For example, the processor 1002 is used to obtain a first Segment Routing for Internet Protocol version 6 (SRv6) message, and the first SRv6 message includes a first protection switching message; the communication interface 1001 is used to send the first SRv6 message to the tail node of the first path, and the first path is the path used to forward the first SRv6 message.

[0368] In one example, the communication device 1000 may execute the method 400 in the foregoing embodiments. When the communication device 1000 is used to execute the method 400 in the foregoing embodiments: The communication interface 1001 is used to execute the transceiver operations in method 400. The processor 1002 is used to execute the operations other than the transceiver operations in method 400. For example, the communication interface 1001 is used to receive a first Segment Routing for Internet Protocol version 6 (SRv6) message, and the first SRv6 message includes a first Automatic Protection Switching (APS) message; the processor 1002 is used to obtain the first APS message from the first SRv6 message.

[0369] In one example, the communication device 1000 may execute the method 500 in the above embodiments. When the communication device 1000 is used to execute the method 500 in the above embodiments: The communication interface 1001 is used to perform the transceiver operations in the method 500. The processor 1002 is used to perform the operations other than the transceiver operations in the method 500. For example, the processor 1002 is used to switch the sending path of the forward service traffic of the first node from the first SRv6 path to the second SRv6 path after a failure occurs in the first Internet Protocol version 6 segment routing (SRv6) path. The forward service traffic is the service traffic sent by the first node to the second node. The first SRv6 path is the path between the first node and the second node. The first node is the head node of the first SRv6 path, and the second node is the tail node of the first SRv6 path. The first SRv6 path and the second SRv6 path have the same head node and tail node. The communication interface 1001 is used to send the forward service traffic through the second SRv6 path.

[0370] In addition, an embodiment of the present application further provides a communication device 1100. Refer to Figure 11 as shown in Figure 11 a schematic structural diagram of a communication device provided by an embodiment of the present application.

[0371] The communication device 1100 can be used to execute the method 100, method 200, method 300, method 400, or method 500 in the above embodiments.

[0372] As Figure 11As shown, the communication device 1100 may include a processor 1110, a memory 1120 coupled to the processor 1110, and a transceiver 1130. The transceiver 1130 may be, for example, a communication interface, an optical module, etc. The processor 1110 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor may also be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The above PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The processor 1110 may refer to a single processor or may include multiple processors. The memory 1120 may include a volatile memory, such as a random-access memory (RAM); the memory may also include a non-volatile memory, such as a read-only memory (ROM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD); the memory 1120 may also include a combination of the above types of memories. The memory 1120 may refer to a single memory or may include multiple memories. In one embodiment, computer-readable instructions are stored in the memory 1120, and the computer-readable instructions include multiple software modules, such as a sending module 1121, a processing module 1122, and a receiving module 1123. After the processor 1110 executes each software module, it may perform corresponding operations according to the instructions of each software module. In this embodiment, the operations performed by a software module actually refer to the operations performed by the processor 1110 according to the instructions of the software module.

[0373] In one example, the communication device 1100 may execute the method 100 in the above embodiments. When the communication device 1100 is used to execute the method 100 in the above embodiments: The transceiver 1130 is used to execute the transceiver operations performed by the communication device 1 in the method 100. The processor 1110 is used to execute the operations other than the transceiver operations performed by the communication device 1 in the method 100. For example, the processor 1110 is used to generate a message 1, where the message 1 includes an APS message 1, and the message 1 is an SRv6 message; the transceiver 1130 is used to send the message 1 to the communication device 2.

[0374] In one example, the communication device 1100 may execute the method 100 in the above embodiments. When the communication device 1100 is used to execute the method 100 in the above embodiments: The transceiver 1130 is used to execute the transceiver operations performed by the communication device 2 in the method 100. The processor 1110 is used to execute the operations other than the transceiver operations performed by the communication device 2 in the method 100. For example, the transceiver 1130 is used to receive a message 1, where the message 1 includes an APS message 1, and the message 1 is an SRv6 message; the processor 1110 is used to obtain the APS message 1 from the message 1.

[0375] In one example, the communication device 1100 may execute the method 200 in the above embodiments. When the communication device 1100 is used to execute the method 200 in the above embodiments: The transceiver 1130 is used to execute the transceiver operations performed by the communication device 1 in the method 200. The processor 1110 is used to execute the operations other than the transceiver operations performed by the communication device 1 in the method 200. For example, the processor 1110 is used to generate a message 1, where the message 1 includes an APS message 1, and the message 1 is an MPLS message; the transceiver 1130 is used to send the message 1 to the communication device 2.

[0376] In one example, the communication device 1100 may execute the method 200 in the above embodiments. When the communication device 1100 is used to execute the method 200 in the above embodiments: The transceiver 1130 is used to execute the transceiver operations performed by the communication device 2 in the method 200. The processor 1110 is used to execute the operations other than the transceiver operations performed by the communication device 2 in the method 200. For example, the transceiver 1130 is used to receive a message 1, where the message 1 includes an APS message 1, and the message 1 is an MPLS message; the processor 1110 is used to obtain the APS message 1 from the message 1.

[0377] In one example, the communication device 1100 may execute the method 300 in the foregoing embodiments. When the communication device 1100 is used to execute the method 300 in the foregoing embodiments: The transceiver 1130 is used to perform the transceiver operations in the method 300. The processor 1110 is used to perform the operations other than the transceiver operations in the method 300. For example, the processor 1110 is used to obtain a first Segment Routing for Internet Protocol version 6 (SRv6) packet, and the first SRv6 packet includes a first protection switching message; the transceiver 1130 is used to send the first SRv6 packet to the tail node of the first path, and the first path is the path for forwarding the first SRv6 packet.

[0378] In one example, the communication device 1100 may execute the method 400 in the foregoing embodiments. When the communication device 1100 is used to execute the method 400 in the foregoing embodiments: The transceiver 1130 is used to perform the transceiver operations in the method 400. The processor 1110 is used to perform the operations other than the transceiver operations in the method 400. For example, the transceiver 1130 is used to receive a first Segment Routing for Internet Protocol version 6 (SRv6) packet, and the first SRv6 packet includes a first Automatic Protection Switching (APS) message; the processor 1110 is used to obtain the first APS message from the first SRv6 packet.

[0379] In one example, the communication device 1100 may execute the method 500 in the foregoing embodiments. When the communication device 1100 is used to execute the method 500 in the foregoing embodiments: The transceiver 1130 is used to perform the transceiver operations in the method 500. The processor 1110 is used to perform the operations other than the transceiver operations in the method 500. For example, after a failure occurs in a first Segment Routing for Internet Protocol version 6 (SRv6) path, the processor 1110 is used to switch the sending path of the forward service traffic of the first node from the first SRv6 path to a second SRv6 path, where the forward service traffic is the service traffic sent by the first node to a second node, the first SRv6 path is the path between the first node and the second node, the first node is the head node of the first SRv6 path, the second node is the tail node of the first SRv6 path, and the first SRv6 path and the second SRv6 path have the same head node and tail node; the transceiver 1130 is used to send the forward service traffic through the second SRv6 path.

[0380] The present application further provides a computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When the instructions run on a computer, the computer is enabled to perform any one or more operations in the methods (for example, method 100, method 200, method 300, method 400, and method 500) described in any one of the foregoing embodiments.

[0381] The present application also provides a computer program product, including a computer program which, when running on a computer, causes the computer to perform any one or more operations of the methods described in any of the foregoing embodiments (e.g., Method 100, Method 200, Method 300, Method 400, and Method 500).

[0382] The present application also provides a communication system, including Communication Device 1 that executes Method 100 and Communication Device 2 that executes Method 100 as mentioned in the foregoing embodiments, or including Communication Device 1 that executes Method 200 and Communication Device 2 that executes Method 200 as mentioned in the foregoing embodiments.

[0383] The present application also provides a communication system, including a communication device that executes Method 300 and a communication device that executes Method 400 as mentioned in the foregoing embodiments, or including a communication device that executes Method 300 and a communication device that executes Method 500 as mentioned in the foregoing embodiments.

[0384] The present application also provides a communication system, including at least one memory and at least one processor. The at least one memory stores instructions, and the at least one processor executes the instructions, causing the communication system to perform any one or more operations of Method 100 in the foregoing embodiments of the present application; or causing the communication system to perform any one or more operations of Method 200 in the foregoing embodiments of the present application.

[0385] The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances, so that the embodiments described herein can be implemented in an order different from that illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0386] 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 foregoing method embodiments, and will not be elaborated herein.

[0387] In several embodiments provided by 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 merely illustrative. For example, the division of units is only a logical service division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed coupling, direct coupling, or communication connection to each other can be an indirect coupling or communication connection through some interfaces, devices, or units, and can be in electrical, mechanical, or other forms.

[0388] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0389] In addition, in each embodiment of the present application, each service unit can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software service units.

[0390] If the integrated unit is implemented in the form of a software service unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in each embodiment of the present application. And the aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0391] Those skilled in the art should be able to realize that in one or more of the above examples, the operations described in the present invention can be implemented by hardware, software, firmware, or any combination thereof. When implemented using software, these operations can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. The computer-readable medium includes computer storage media and communication media, where the communication media includes any medium that facilitates the transfer of a computer program from one place to another. The storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0392] The above specific implementation manners have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above is only the specific implementation manner of the present invention.

[0393] The above, the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the various embodiments of the present application.

Claims

1. A protection switching method, characterized in that, the method includes: obtaining a first Segment Routing for IPv6 (SRv6) packet, the first SRv6 packet including a first protection switching message for requesting a tail node of a first path to switch a traffic transmission path from a second path to a third path, wherein the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path; sending the first SRv6 packet to the tail node of the first path, the first path being the path for forwarding the first SRv6 packet.

2. The method according to claim 1, characterized in that, the first protection switching message is carried in an extension header of the first SRv6 packet, and the extension header is: a Hop-by-Hop (HBH) options header, or, a Destination Options (DOH) header, or, a Segment Routing (SRH) header.

3. The method according to claim 1 or 2, characterized in that, the first SRv6 packet includes first indication information for indicating the first protection switching message.

4. The method according to claim 3, characterized in that, the first indication information is a first path identifier for identifying the first path.

5. The method according to claim 4, characterized in that, the first path identifier is further used to identify the second path.

6. The method according to claim 5, characterized in that, the first path identifier is further used to identify at least one service transmitted on the second path, and the first protection switching message for requesting the tail node of the first path to switch a traffic transmission path from the second path to the third path includes: the first protection switching message is used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

7. The method according to any one of claims 4-6, characterized in that, the first path identifier is: a first path segment identifier.

8. The method according to claim 4, characterized in that, the first SRv6 packet further includes a second path identifier for identifying the second path.

9. The method according to claim 8, characterized in that, the second path identifier is further used to identify at least one service transmitted on the second path, and the first protection switching message for requesting the tail node of the first path to switch a traffic transmission path from the second path to the third path includes: the first protection switching message is used to request the tail node of the first path to switch the transmission path of the at least one service from the second path to the third path.

10. The method according to claim 8 or 9, characterized in that, the second path identifier is: a second path segment identifier.

11. The method according to claim 5, characterized in that, the method further includes: Receive a second SRv6 packet through the third path, where the second SRv6 packet includes a second protection switching message, and the second protection switching message is a response message to the first protection switching message.

12. The method according to claim 3, wherein, a first type-length-value TLV is included in the extension header of the first SRv6 packet, and the first TLV is used to carry the first indication information and the first protection switching message.

13. The method according to claim 12, wherein, the first TLV is an associated channel TLV, the associated channel TLV includes a channel type field, the channel type field is used to carry the first indication information, and the value field of the associated channel TLV is used to carry the first protection switching message.

14. The method according to claim 3, wherein, the first SRV6 packet includes an associated channel, the associated channel can carry different types of control channels, and one type of control channel is a protection switching channel, and the protection switching channel is used to carry the first indication information and the first protection switching message.

15. The method according to claim 14, wherein, the first SRV6 packet includes second indication information, and the second indication information is used to indicate the associated channel.

16. The method according to any one of claims 12-15, wherein, the method further includes: receiving a second SRv6 packet sent by the tail node of the first path, where the second SRv6 packet includes a second protection switching message.

17. A protection switching method, wherein, the method includes: receiving a first Internet Protocol version 6 segment routing SRv6 packet, the first SRv6 packet includes a first automatic protection switching APS message, and the first APS message is used to request the tail node of the first path to switch the traffic transmission path from the second path to the third path, wherein the second path and the third path have the same head node and tail node, the tail node of the first path is the head node of the second path, and the head node of the first path is the tail node of the second path, and the first path is the path for forwarding the first SRv6 packet; obtaining the first APS message from the first SRv6 packet.

18. The method according to claim 17, wherein, further includes: switching the traffic transmission path from the second path to the third path based on the first APS message.

19. The method according to claim 18, wherein, the method further includes: sending a second SRv6 packet to the head node of the first path through the third path, the second SRv6 packet includes a second APS message, and the second APS message is a response message to the first APS message.

20. A protection switching method, wherein, for a first node, the method includes: After a failure occurs in the first Internet Protocol version 6 segment routing (SRv6) path, switch the transmission path of the forward service traffic of the first node from the first SRv6 path to the second SRv6 path. The forward service traffic is the service traffic sent by the first node to the second node. The first SRv6 path is the path between the first node and the second node. The first node is the head node of the first SRv6 path, and the second node is the tail node of the first SRv6 path. The first SRv6 path and the second SRv6 path have the same head node and tail node; Transmit the forward service traffic through the second SRv6 path; Before the first node switches the transmission path of the forward service traffic from the first SRv6 path to the second SRv6 path, the method further includes: The first node receives a first SRv6 packet sent by the second node. The first SRv6 packet includes a first protection switching message, which is used to request the tail node of the third SRv6 path to switch the transmission path of the traffic from the first SRv6 path to the second SRv6 path. The first node is the tail node of the third SRv6 path, and the second node is the head node of the third SRv6 path; The step of switching the transmission path of the forward service traffic of the first node from the first SRv6 path to the second SRv6 path includes: According to the first protection switching message, switch the transmission path of the forward service traffic of the first node from the first SRv6 path to the second SRv6 path.

21. The method according to claim 20, wherein, after the failure of the first SRv6 path, the method further includes: Switch the receiving path of the reverse service traffic of the first node from the third SRv6 path to the fourth SRv6 path. The reverse service traffic is the traffic sent by the second node to the first node. Among them, the head node of the third SRv6 path is the second node, the tail node of the third SRv6 path is the first node, and the third SRv6 path and the fourth SRv6 path have the same head node and tail node; Receive the reverse service traffic through the fourth SRv6 path.

22. The method according to claim 21, wherein, the fourth SRv6 path and the second SRv6 path are bidirectional common path.

23. The method according to any one of claims 20-22, wherein, the first node stores a first segment list, and the first segment list is used to describe the set of segment identifiers (SIDs) of the second SRv6 path.

24. The method according to claim 20, wherein, the first SRv6 packet further includes first information, and the first information is used to identify the first SRv6 path.

25. The method according to claim 24, wherein, the first node stores a first segment list, including: The first node stores the correspondence between the first information and the first segment list.

26. The method according to claim 25, wherein, sending the forward service traffic through the second SRv6 path includes: determining the first segment list according to the correspondence and the first information; encapsulating the forward service traffic by using the first segment list; sending the forward service traffic through the second SRv6 path.

27. The method according to any one of claims 24-26, wherein, the first information includes: A first path segment identifier.

28. A communication device, wherein, configured to execute the method according to any one of claims 1-27, the device includes: a transceiver unit, configured to implement operations related to reception and / or transmission in the method according to any one of claims 1-27; a processing unit, configured to execute operations other than the reception and / or transmission.

29. A communication device, wherein, the communication device includes a memory and a processor; the memory is configured to store program code; the processor is configured to run instructions in the program code, so that the communication device executes the method according to any one of claims 1-27 above.

30. A computer program product, wherein, including a program, when the program runs on a processor, implementing the method according to any one of claims 1-27.

31. A communication system, wherein, the communication system includes: a communication device that executes the method according to any one of claims 1-16 above and a communication device that executes the method according to any one of claims 17-19; or, a communication device that executes the method according to any one of claims 1-16 above and a communication device that executes the method according to any one of claims 20-27.

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