A seamless redundant transmission method based on improved FRER

Abstract

The invention relates to the technical field of industrial time-sensitive network communication, and in particular to a seamless redundant transmission method based on improved FRER; the method designs an improved vector elimination method based on dynamic history table length, dynamically adjusts the history table length of frame replication and frame elimination technology of IEEE802.1CB standard through basic traffic attributes of service flow, and realizes high-reliability seamless redundant transmission of Ethernet; FPGA can improve the processing speed of each component and reduce the exchange delay of seamless redundant transmission; the improved vector elimination method based on dynamic history table length can effectively curb the problem of elimination algorithm failure caused by excessive delay difference of redundant paths, thereby improving the bandwidth utilization and reliability of the seamless redundant transmission method.

Description

Technical Field

[0001] The invention relates to the technical field of industrial time-sensitive network communication, and in particular to a seamless redundant transmission method based on improved FRER. Background Art

[0002] Industrial Internet is the core of smart manufacturing and smart factories. It connects all aspects of industrial manufacturing and aims to improve manufacturing efficiency, optimize production management, promote the transformation and upgrading of the industrial manufacturing field and continuously develop the national economy at a high speed. The deterministic latency requirements of emerging time-sensitive services in data transmission have challenged the existing Ethernet. To this end, the IEEE802.1 working group proposed the time-sensitive networking (TSN) protocol. TSN is based on the wired Ethernet based on IEEE802.3, and adds and expands a series of functions and protocol standards, which improves the ability of Ethernet to support real-time applications. While providing time-sensitive services with bounded latency and high reliability, it can also provide high-speed but best-effort transmission services for non-time-sensitive services.

[0003] As the core standard of TSN reliability, IEEE802.1CB works at the data link layer of full-duplex Ethernet. It uses redundant topology networks as its physical basis and combines frame replication and frame elimination technology (FRER) to achieve seamless redundant transmission of time-sensitive services in time-sensitive networks to improve their service reliability. Compared with traditional Internet reliability technologies RSTP and MSTP, FRER has the characteristic of zero self-healing time, and it can adapt to a variety of network topologies, has high flexibility and scalability, and low management costs. The IEEE 802.1CB protocol has an independent structure and strong scalability, providing high-reliability service transmission services for many fields such as automated factories, automotive control, aerospace, etc.

[0004] FRER technology mainly splits the original stream into one or more member streams at the sending end, making the original stream a composite stream composed of multiple member streams, and copies the data frames of the original stream to the member streams. These member streams will be sent to the destination node through different redundant paths. Then, these member streams are combined at other nodes, duplicate data frames are eliminated, and the reconstructed data streams are sent. This protocol can effectively reduce the path planning time caused by equipment failure. The accuracy of the elimination algorithm in FRER technology determines whether there is additional bandwidth consumption for seamless redundant transmission. The vector elimination algorithm in the IEEE standard protocol will fail due to the large transmission delay difference between two or more redundant paths, resulting in the failure of the data frames that should be eliminated, resulting in additional bandwidth consumption. In addition, these data frames that should be eliminated but are not eliminated may also affect the network and terminal devices. At the same time, due to the addition of components such as flow identification and frame elimination, the switching performance may also be reduced and the switching delay may increase, which violates the low latency requirement of industrial control networks.

[0005] In summary, the existing seamless redundant transmission technology in the industrial Internet of Things lacks the ability to cope with a variety of network topologies, has low scalability, and has high management costs. Frame replication and frame elimination technologies have problems such as additional bandwidth consumption and reduced reliability due to the defects of the vector elimination algorithm, and also have the problem of reduced switching performance due to the addition of components. Therefore, solving the defects of the vector elimination algorithm itself and improving the performance of multiple components have become the research focus of this invention. Summary of the invention

[0006] To solve the above problems, the present invention provides a seamless redundant transmission method based on improved FRER. The method designs an improved vector elimination method based on dynamic history table length, dynamically adjusts the history table length of frame replication and frame elimination technology of IEEE802.1CB standard through basic traffic attributes of service flow, and realizes high-reliability seamless redundant transmission of Ethernet.

[0007] The devices in Ethernet include data generating terminals, data receiving terminals, centralized control nodes and switching nodes;

[0008] Centralized control node, used to receive seamless redundant transmission request messages of key business flows, configure relevant data for key business flows and pack them into control messages, and then send control messages to multiple switching nodes;

[0009] The switching node has a flow identification component, a frame replication component, and a frame elimination component, wherein:

[0010] Flow identification component, used to identify key business flows;

[0011] A frame replication component, which is used to replicate a critical service flow to obtain multiple identical critical service flows, and forward the multiple identical critical service flows through different ports;

[0012] A frame elimination component, which is used to eliminate redundant copies of the critical service flow according to an improved vector elimination method based on the dynamic history table length.

[0013] Further, at a certain switching node, the process of eliminating redundant copies of the critical service flow according to the improved vector elimination method based on the dynamic history table length includes:

[0014] S11. Receive the k-th data frame of the critical service flow, obtain the sequence number parameter in the R-tag label of the k-th data frame of the critical service flow through the encoding and decoding component, and subtract it from the maximum sequence number parameter of the critical service flow recorded by this switching node to obtain the difference Delta k ;

[0015] S12. Calculate the weighted average of the difference Delta k and adjust the length of the corresponding history table according to the weighted average of the difference Delta k to obtain the updated history table length value historylength;

[0016] S13. Judge whether the condition -historylength < Delta k < historylength is satisfied; if it is satisfied, execute step S14; if it is not satisfied, discard the k-th data frame;

[0017] S14. Judge whether the condition Delta k > 0 is satisfied; if it is satisfied, execute step S15; if it is not satisfied, execute step S16;

[0018] S15. Judge whether the condition Delta k = 1 is satisfied; if it is satisfied, move the history table one position backward and insert 1 at its head, and then execute step S17; if it is not satisfied, move the history table one position backward and insert 0 at its head, and then update Delta k and return to step S15;

[0019] S16. Judge whether the boolean value corresponding to the sequence number parameter in the history table is equal to 0; if it is, set the boolean value corresponding to the sequence number parameter in the history table to 1, and then execute step S17; if it is not, discard the k-th data frame;

[0020] S17. Update the maximum sequence number parameter of the critical service flow recorded by this switching node.

[0021] Further, step S12 calculates the difference Delta k The weighted average Delta avg k The formula is:

[0022] Delta avg k =αDelta avg k-1 +(1-α)Delta k

[0023] Among them, α represents the weight factor.

[0024] Further, according to the difference Delta k The weighted average of the history table is used to adjust the length of the history table to obtain the updated history table length value historylength, which is calculated as follows:

[0025] historylength = INT(L + Delta avg k )

[0026] Wherein, L represents the initial length of the history table, and INT() represents the rounding down function.

[0027] Furthermore, the calculation formula for the initial length of the history table is:

[0028]

[0029] Among them, Delay P1 Indicates the delay information of the redundant path P1 of the key business flow, Delay P2 represents the delay information of the redundant path P2 of the key business flow, B represents the average frame length of the key business flow, and W represents the fixed constant coefficient.

[0030] Furthermore, the control message includes a MAC message header, basic configuration information of the switching node, and multiple service flow information; each service flow information includes a flow identification type, basic service flow information, elimination algorithm information, and redundant path information, wherein the basic service flow information includes the source MAC address, destination MAC address, VLAN ID information, and destination IP address of the service flow.

[0031] Furthermore, based on the FPGA hardware, the recognition speed of the flow recognition component is enhanced. The flow recognition process of any switching node using the flow recognition component mainly includes:

[0032] S21 receives a data frame of the service flow, extracts the basic information of the service flow of the data frame, the basic information of the service flow includes the source MAC address, destination MAC address, VLAN ID information and destination IP address of the data frame;

[0033] S22. The flow identification component matches the flow identification mode according to the basic information of the business flow, obtains the key information required for the matched flow identification mode in the data frame and maps it into 8-bit data through the FPGA;

[0034] S23. The flow identification component uses the 8-bit data as the flow identification storage list address and reads the corresponding entry data in the data storage list for flow identification matching;

[0035] S24. If the flow identification match is successful, the data storage list address of the business flow basic information of the data frame in the flow identification component is used as the flow handle of the data frame, and the data frame and its flow handle are submitted to the subsequent component together; if the flow identification match fails, step S25 is executed;

[0036] S25. Determine whether the data frame contains an R-tag label. If so, add the basic business flow information of the data frame to the data storage list of the flow identification component, and use the data storage list address as the flow handle of the data frame, and submit the data frame and its flow handle together to the subsequent components; if not, the data frame is directly exchanged and forwarded by Ethernet data frame.

[0037] Furthermore, the data storage list of the flow identification component is composed of 4 high-speed RAMs and 1 LUT (lookup table resource), and the 4 high-speed RAMs form a storage array.

[0038] Beneficial effects of the present invention:

[0039] The present invention provides a seamless redundant transmission method based on improved FRER, which realizes seamless redundant transmission by combining FPGA hardware design and improved vector elimination algorithm. FPGA can improve the processing speed of each component and reduce the exchange delay of seamless redundant transmission; the improved vector elimination method based on the length of dynamic history table can effectively curb the problem of elimination algorithm failure caused by excessive delay difference of redundant path, thereby improving the bandwidth utilization and reliability of the seamless redundant transmission method. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a flow chart of the seamless redundant transmission method of the industrial time-sensitive network in the present invention;

[0041] Figure 2 It is a network model of the seamless redundant transmission method of the present invention;

[0042] Figure 3It is the management control node message format in the embodiment of the present invention;

[0043] Figure 4 It is the flow identification data storage list structure of the present invention;

[0044] Figure 5 This is a flow chart of the improved vector elimination algorithm of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In one embodiment, a seamless redundant transmission method based on improved FRER is proposed. The method designs an improved vector elimination method based on dynamic history table length, dynamically adjusts the history table length of the frame replication and frame elimination technology of the IEEE802.1CB standard through the basic traffic attributes of the service flow, and realizes high-reliability seamless redundant transmission of Ethernet.

[0047] The devices in Ethernet include data generating terminals, data receiving terminals, centralized control nodes and switching nodes; the service flows include key service flows that require seamless redundant transmission and common service flows that do not require seamless redundant transmission;

[0048] The centralized control node is used to receive seamless redundant transmission request messages of key business flows, configure relevant data for key business flows and package them into control messages, and then send control messages to multiple switching nodes; at the same time, the centralized control node also receives fault information messages periodically reported by switching nodes to understand the transmission status of business flows;

[0049] Specifically, the format of the control message is as follows: Figure 3 As shown, it includes a MAC message header, basic configuration information of the switching node, and business flow information of multiple key business flows that require seamless redundant transmission; each business flow information includes flow identification type, business flow basic information, elimination algorithm information, and redundant path information, wherein the business flow basic information includes the source MAC address, destination MAC address, VLAN ID information, and destination IP address of the key business flow.

[0050] Specifically, the centralized control node will plan redundant paths for seamless redundant transmission of key business flows based on the network topology information, and configure some switching nodes involved in the planned redundant paths as replication nodes or elimination nodes (configured as replication nodes means that replication operations need to be performed at the switching node according to the frame replication component, and configured as elimination nodes means that elimination operations need to be performed at the switching node according to the frame elimination component). Based on the planned redundant path information, the centralized control node sends control messages to all switching nodes involved in the redundant paths.

[0051] The switching nodes constitute redundant transmission paths for sending service flows; all switching nodes have FRER functions or partial FRER functions, which include flow identification components, frame replication components, and frame elimination components, among which:

[0052] The flow identification component is used to identify the service flow received by the switching node. If the service flow is identified as a key service flow that requires seamless redundant transmission, a flow handle corresponding to the key service flow is generated and then submitted to the subsequent components.

[0053] A frame replication component is used to generate a sequence number parameter according to a flow handle of a key business flow, and then replicate the key business flow to obtain multiple copies of the same key business flow, and forward the multiple copies of the same key business flow through different ports;

[0054] Specifically, the serial number parameter is encapsulated into an R-tag label through the encoding and decoding component, and then the R-tag label is inserted into the data frame header (ie, Ethernet frame header) of its corresponding key service flow.

[0055] The frame elimination component is used to eliminate redundant copies of key business flows according to the improved vector elimination method based on the length of the dynamic history table. When the switching node performs the frame elimination operation, it will record the elimination status of the current key business flow, and the switching node will upload the specific information to the centralized control node through the periodic reporting of fault information messages.

[0056] Preferably, this embodiment adopts Figure 2The industrial control TSN network model shown in the figure mainly includes multiple terminals, multiple switching nodes and a centralized control node, which ensures the reliability of time-sensitive services through multi-plane seamless redundant transmission. Assuming that the time-sensitive service flow (critical service flow) is from terminal A to terminal B, and terminal A and terminal B do not have the FRER function, the switching node with the FRER function connected to terminal A is called the talker node, which serves as the FRER agent of terminal A; the switching node with the FRER function connected to terminal B is called the listener node, which serves as the FRER agent of terminal B. The centralized control node receives the seamless redundant transmission request message of the time-sensitive service flow sent by terminal A, and then plans a redundant path for the time-sensitive service flow, and configures some or all of the switching nodes involved in the redundant path as elimination nodes or copy nodes, and then packages and encapsulates them into the control message. The centralized control node sends the control message to all the switching nodes involved in the redundant path of the time-sensitive service flow, so that the switching nodes can perform seamless redundant transmission operations.

[0057] Specifically, in Figure 2 The centralized control node receives the seamless redundant transmission request message of the time-sensitive service flow sent by terminal A and plans two redundant paths: talker-switch node 1-switch node 2-listener and talker-switch node 3-switch node 4-listener. At the same time, the talker is configured as a replication node, the listener is configured as an elimination node, and the other switch nodes remain unchanged. The centralized control node encapsulates the redundant path information and node configuration information into the control message, and then sends the control message to the talker, switch node 1, switch node 2, switch node 3, switch node 4, and listener involved in the redundant path. The time-sensitive service flow sent by terminal A is directly transmitted to the talker node. The talker node copies a time-sensitive service flow according to the frame replication component, and then forwards two identical time-sensitive service flows to two redundant paths. The two time-sensitive service flows are gathered at the listener node. The listener node performs frame elimination operation through the frame elimination component, eliminates the redundant copies and forwards the master copy to terminal B.

[0058] In one embodiment, a seamless redundant transmission method based on improved FRER is described as follows: Figure 1 As shown, the following steps are included:

[0059] S1. The centralized control node receives the data generating terminal to send a seamless redundant transmission request message for the key business flow, encapsulates the basic configuration information and redundant path information of the key business flow switching node to the control message, and sends the control message to all the switching nodes in the redundant path of the key business flow;

[0060] S2. The switching node that receives the control message is configured as a copy node, an elimination node, or remains unchanged according to the basic configuration information of the switching node; the switching node that remains unchanged in the redundant path is used to forward the key business flow and does not perform a copy operation, but in order to cope with the situation where a copy node fails, such a switching node will also be eliminated when necessary;

[0061] S3. The replication node identifies the key business flow according to the flow identification component, replicates the key business flow through the frame replication component to obtain multiple copies, and forwards the multiple copies of the key business flow using different ports;

[0062] S4. The elimination node identifies the key business flow according to the flow identification component, and eliminates redundant copies of the key business flow through the improved vector elimination algorithm in the frame elimination component.

[0063] The service flow includes multiple data frames, each of which contains different partial information, and all data frames of a service flow arrive at the switching node one by one.

[0064] In one embodiment, if Figure 5 As shown, at a certain switching node, the process of eliminating redundant copies of each data frame of a key service flow according to the improved vector elimination method based on the dynamic history table length includes:

[0065] S11. Receive the kth data frame of the key business flow, obtain the sequence number parameter in the R-tag label of the kth data frame of the key business flow through the codec component, and subtract it from the maximum sequence number parameter of the key business flow recorded by the switching node to obtain the difference Delta k ;

[0066] S12. Calculate the difference Delta k The weighted average of k The weighted average of the history table is used to adjust the length of the corresponding history table to obtain the updated history table length value historylength;

[0067] Specifically, calculate the difference Delta k The weighted average Delta avg k The formula is:

[0068] Delta avg k =αDelta avg k-1 +(1-α)Delta k

[0069] Among them, α represents the weight factor.

[0070] Specifically, for the updated historical table length value historylength, its calculation formula is:

[0071] historylength = INT(L + Delta avg k )

[0072] where L represents the initial length of the historical table, and INT() represents the floor function.

[0073] The calculation formula for the initial length of the historical table is:

[0074]

[0075] where Delay P1 represents the delay information of the redundant path P1 of the critical service flow, Delay P2 represents the delay information of the redundant path P2 of the critical service flow, B represents the average frame length of the critical service flow, and W represents a fixed constant coefficient.

[0076] S13. Determine whether the sequence number parameter in the k-th data frame exceeds the reception range, that is, whether the condition -historylength < Delta k < historylength is satisfied; if satisfied, execute step S14; if not satisfied, discard the k-th data frame, and increment the number of discarded data frames DiscardPackets by 1;

[0077] S14. Determine whether the condition Delta k > 0 is satisfied; if satisfied, it means that the k-th data frame is newly received and has no other copies, execute step S15; if not satisfied, it means that the k-th data frame may not be newly received and needs further judgment, execute step S16;

[0078] S15. Determine whether the condition Delta k = 1 is satisfied; if satisfied, it means that the sequence number parameter of the k-th data frame is consecutive with the maximum sequence number parameter of the critical service flow currently recorded by this switching node, or with the sequence number parameter recorded at the head of the historical table; then shift the historical table one position backward and insert 1 at its head, and increment the number of received data frames ReceivedPackets by 1, then execute step S17; if not satisfied, it means that the sequence number parameter of the k-th data frame is neither consecutive with the maximum sequence number parameter of the critical service flow currently recorded by this switching node nor with the sequence number parameter recorded at the head of the historical table; then shift the historical table one position backward and insert 0 at its head, then execute Delta k = Delta k - 1 and return to step S15;

[0079] S16. Determine whether the Boolean value corresponding to the sequence number parameter in the history table is equal to 0. If so, it means that the k-th data frame is newly received and there are no other copies. The Boolean value corresponding to the sequence number parameter in the history table is set to 1, and the number of received data frames ReceivedPackets is increased by 1, and then step S17 is executed; if not, the k-th data frame is discarded, and the number of eliminated data frames DiscardPackets is increased by 1;

[0080] S17. Update the maximum sequence number parameter of the key service flow recorded by the switching node.

[0081] In one embodiment, based on the FPGA hardware to enhance the recognition speed of the flow recognition component, any switching node uses the flow recognition component to perform flow recognition process mainly including:

[0082] S21 receives a data frame of the service flow, extracts the basic information of the service flow of the data frame, the basic information of the service flow includes the source MAC address, destination MAC address, VLAN ID information and destination IP address of the data frame;

[0083] S22. The flow identification component matches the flow identification mode according to the basic information of the business flow, obtains the key information required for the matched flow identification mode in the data frame and maps it into 8-bit data through the FPGA;

[0084] Specifically, the flow identification component includes four flow identification modes: Null Stream identification, Source MAC address and VLAN ID identification, Active identification, and IP address flow identification.

[0085] S23. The flow identification component uses the 8-bit data as the flow identification storage list address and reads the corresponding entry data in the data storage list of the flow identification component for flow identification matching;

[0086] S24. If the flow identification match is successful, the data storage list address of the business flow basic information of the data frame in the flow identification component is used as the flow handle of the data frame, and the data frame and its flow handle are submitted to the subsequent frame replication component or frame elimination component; if the flow identification match fails, execute step S25;

[0087] S25. Determine whether the data frame contains an R-tag label. If so, add the basic business flow information of the data frame to the data storage list of the flow identification component, and use the data storage list address as the flow handle of the data frame. The data frame and its flow handle are submitted together to the frame replication component or the frame elimination component. If not, the data frame is directly exchanged and forwarded by Ethernet data frame.

[0088] Specifically, Figure 4 As shown in the figure, the data storage list of the flow identification component consists of 4 high-speed RAMs and 1 LUT (lookup table resource), and the 4 high-speed RAMs form a storage array. The flow identification component uses 8-bit data as the flow identification storage list address, and reads the corresponding table entry data in the data storage list (storage table of 4 high-speed RAMs) for flow identification matching. The storage table of LUT is used to prevent overflow caused by mapping conflicts. LUT resources can match data in parallel as FPGA high-speed resources.

[0089] In this embodiment, the FPGA clock cycle is 125Mhz, and the flow identification processing speed is within three clock cycles, that is, the flow identification processing speed can be within 24ns. Through the idea of ​​hash storage and balanced FPGA resource utilization, the flow identification component is designed with extremely low processing delay, which can make the entire seamless redundant transmission technology have lower delay and delay jitter, and can meet the delay requirements of industrial networks.

[0090] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "rotation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0091] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A seamless redundant transmission method based on improved FRER, characterized in that: This method designs an improved vector elimination method based on dynamic history table length, dynamically adjusts the history table length of frame replication and frame elimination technology of IEEE802.1CB standard through the basic traffic attributes of the service flow, and realizes high-reliability seamless redundant transmission of Ethernet. The devices in Ethernet include data generating terminals, data receiving terminals, centralized control nodes and switching nodes; Centralized control node, used to receive seamless redundant transmission request messages of key business flows, configure relevant data for key business flows and pack them into control messages, and then send control messages to multiple switching nodes; The switching node has a flow identification component, a frame replication component, and a frame elimination component, wherein: Flow identification component, used to identify key business flows; A frame replication component is used to replicate a key business flow to obtain multiple identical key business flows, and forward the multiple identical key business flows through different ports; A frame elimination component for eliminating redundant copies of key service flows according to an improved vector elimination method based on a dynamic history table length; At a certain switching node, the process of eliminating redundant copies of key business flows according to the improved vector elimination method based on the dynamic history table length includes: S11. Receive the kth data frame of the key business flow, obtain the sequence number parameter in the R-tag label of the kth data frame through the codec component, and subtract it from the maximum sequence number parameter of the key business flow recorded by the switching node to obtain the difference Delta k ; S12. Calculate the difference Delta k The weighted average of k The weighted average of the history table is used to adjust the length of the corresponding history table to obtain the updated history table length value historylength; S13. Determine whether the condition - historylength < Delta is satisfied k <historylength; if satisfied, execute step S14; if not satisfied, discard the k-th data frame; S14. Determine whether the condition Delta is met k >0; if satisfied, execute step S15; if not satisfied, execute step S16; S15. Determine whether the condition Delta is met k =1; if satisfied, the history table is shifted back one position and 1 is inserted at its head, and then step S17 is executed; if not satisfied, the history table is shifted back one position and 0 is inserted at its head, and then Delta is updated k And return to step S15; S16. Determine whether the Boolean value corresponding to the sequence number parameter in the history table is equal to 0. If so, set the Boolean value corresponding to the sequence number parameter in the history table to 1, and then execute step S17; if not, discard the kth data frame; S17. Update the maximum sequence number parameter of the key service flow recorded by the switching node; Step S12: Calculate the difference Delta k The weighted average Delta avg k The formula is: Delta avg k =αDelta avg k-1 +(1-α)Delta k Among them, α represents the weight factor; According to the difference Delta k The weighted average of the history table is used to adjust the length of the history table to obtain the updated history table length value historylength, which is calculated as follows: historylength=INT(L+Delta avg k ) Where, L represents the initial length of the history table, and INT() represents the rounding down function; The calculation formula for the initial length of the history table is: Among them, Delay P1 Indicates the delay information of the redundant path P1 of the key business flow, Delay P2 represents the delay information of the redundant path P2 of the key business flow, B represents the average frame length of the key business flow, and W represents the fixed constant coefficient.

2. A seamless redundant transmission method based on improved FRER according to claim 1, characterized in that: The control message includes a MAC message header, basic configuration information of the switching node, and multiple service flow information; each service flow information includes flow identification type, basic service flow information, elimination algorithm information, and redundant path information, wherein the basic service flow information includes the source MAC address, destination MAC address, VLAN ID information, and destination IP address of the service flow.

3. A seamless redundant transmission method based on improved FRER according to claim 1, characterized in that: Based on FPGA hardware to enhance the recognition speed of the flow recognition component, any switching node uses the flow recognition component to perform flow recognition process mainly including: S21 receives a data frame of the service flow, extracts the basic information of the service flow of the data frame, the basic information of the service flow includes the source MAC address, destination MAC address, VLAN ID information and destination IP address of the data frame; S22. The flow identification component matches the flow identification mode according to the basic information of the business flow, obtains the key information required for the matched flow identification mode in the data frame and maps it into 8-bit data through the FPGA; S23. The flow identification component uses the 8-bit data as the flow identification storage list address and reads the corresponding entry data in the data storage list for flow identification matching; S24. If the flow identification match is successful, the data storage list address of the business flow basic information of the data frame in the flow identification component is used as the flow handle of the data frame, and the data frame and its flow handle are submitted to the subsequent component together; if the flow identification match fails, step S25 is executed; S25. Determine whether the data frame contains an R-tag label. If so, add the basic business flow information of the data frame to the data storage list of the flow identification component, and use the data storage list address as the flow handle of the data frame, and submit the data frame and its flow handle together to the subsequent components; if not, the data frame is directly exchanged and forwarded by Ethernet data frame.

4. The seamless redundant transmission method based on improved FRER according to claim 1, characterized in that: The data storage list of the flow identification component consists of 4 high-speed RAMs and 1 LUT, and the 4 high-speed RAMs form a storage array.

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