DDS and TSN automatic integration configuration architecture and method

Abstract

The invention relates to a DDS and TSN automatic integration configuration architecture and method, the architecture comprises an application layer, a control layer and a data layer, the application layer comprises a DDS publisher and a DDS subscriber, the control layer comprises a DS server and a TSN controller, and the data layer comprises a TSN switch deployed in an end system and a network by the DDS application; the TSN controller establishes a connection with the DDS server, so that the DDS server sends the collected information to the TSN controller through the connection to request the reserved time slot of the network resource; the TSN controller outputs an L2 forwarding table, a gating list and a publishing moment which meet multicast transmission through a routing scheduling algorithm; and the L2 forwarding table and the gating list are issued to the TSN switch for configuration, the issuing moment is replied to the DDS server as the response of the request, and the DDS server dynamically configures the moment when the issuer starts to send data. Compared with the prior art, the real-time transmission of the DDS key task flow is ensured while the integration complexity of the DDS key task flow and the DDS key task flow is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a DDS and TSN automated integrated configuration architecture and method. Background Art

[0002] Data Distribution Service (DDS) is a data-centric communication middleware that provides dynamic publishing and subscription for the system, aiming to promote efficient and scalable data distribution in distributed real-time systems. DDS supports multiple quality of service (QoS) strategies such as reliability, persistence, and real-time to meet the needs of different application scenarios. These features make DDS an ideal choice for real-time data communication and distribution.

[0003] As an underlying network technology, time-sensitive networking (TSN) provides mechanisms such as clock synchronization and traffic scheduling, which can effectively guarantee the bandwidth and latency requirements of data transmission. Therefore, using TSN as the underlying transmission mechanism of DDS can provide deterministic data transmission for key tasks in the system. DDS and TSN are two independent protocols proposed and maintained by two organizations. There are still the following problems to integrate them to achieve real-time and reliable data communication:

[0004] 1) The time-aware scheduling mechanism in TSN needs to control the forwarding of messages based on precise time windows. Therefore, it is necessary to control the time when DDS publishes data to align the transmission window in TSN. However, standard DDS uses asynchronous transmission and does not have time-aware capabilities.

[0005] 2) Usually DDS uses unicast to send data packets, and the destination MAC address in the message is the MAC address of the subscriber's end system. The TSN switch needs to parse the received data packet to obtain the IP address and port number in order to identify the DDS data stream. This method will reduce processing efficiency and is not conducive to the deterministic transmission of DDS messages by TSN.

[0006] 3) The TSN system needs to accurately obtain information such as DDS deployment, traffic, and QoS to ensure that the messages sent by DDS are correctly processed at the data link layer to meet the needs of real-time data transmission. However, there is currently a lack of a mechanism for autonomous interaction between DDS and TSN, and DDS and TSN can only be configured manually.

[0007] 4) The integration of DDS and TSN lacks a method to automatically complete a series of tasks from the perception of transmission needs to the calculation of routing and scheduling and finally to the configuration of peer nodes and switches. If static configuration is done manually, it will generate a huge workload and also destroy the scalability of DDS, and cannot meet the transmission needs under dynamic conditions. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a DDS and TSN automated integrated configuration architecture and method. Through automated traffic perception, calculation and configuration, it realizes integration with the TSN system before DDS releases data, effectively reducing the complexity of integration between the two while ensuring the real-time transmission of DDS key task flows.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] According to a first aspect of the present invention, there is provided a DDS and TSN automated integrated configuration architecture, comprising an application layer, a control layer and a data layer, wherein the application layer comprises a publisher and a subscriber of DDS, the control layer comprises a DDS server as a centralized user configuration module and a TSN controller as a centralized network configuration module, and the data layer comprises a TSN switch in an end system and a network where a DDS application is deployed;

[0011] The TSN controller establishes a connection with the DDS server, and the DDS server sends the collected information to the TSN controller through the connection to request a reserved transmission time slot of network resources;

[0012] The TSN controller outputs an L2 forwarding table, a gating list and a publishing schedule that meet the requirements of multicast transmission through a routing scheduling algorithm; wherein the L2 forwarding table and the gating list are sent to the TSN switch for configuration, and the publishing schedule is replied to the DDS server as a response to the request, and the DDS server dynamically configures the time when the publisher starts to send data;

[0013] The TSN switch is used to forward the multicast DDS message according to the locally configured L2 forwarding table and gating list.

[0014] According to a second aspect of the present invention, a method for automatic integration configuration of DDS and TSN is provided, applying the above architecture, the method comprising:

[0015] After the DDS server discovers a new topic, it assigns it a dedicated multicast locator for subsequent data transmission;

[0016] The DDS server extracts the DDS stream information from the discovery message sent by the DDS client, and sends the DDS stream information to the TSN controller to request dynamic configuration;

[0017] After receiving the request sent by the DDS server, the TSN controller generates TSN flow information based on the global network topology information and the DDS flow information, and inputs the TSN flow information into the routing scheduling algorithm. The routing scheduling algorithm outputs the L2 forwarding table for path control of the TSN, the gating list, and the publishing schedule for the DDS publisher to start sending data, and then transmits the publishing schedule to the DDS server as a reply, and sends the L2 forwarding table and the gating list to the TSN switch;

[0018] After receiving the reply from the TSN controller, the DDS server extracts the sending time of each topic and forwards the sending time to the corresponding DDS publisher through the discovery message;

[0019] After receiving the discovery message with the start publishing time set from the DDS server, the DDS publisher completes the publishing configuration of the local publishing time and enters the waiting state, and starts to send data periodically after the configured time arrives;

[0020] After receiving the configuration message containing the YANG model, the TSN switch completes the dynamic configuration of the local L2 forwarding table and gating list based on the extracted configuration information.

[0021] Preferably, based on the client-server discovery mode, the discovery mechanism of DDS is used to collect user-network interface implementation information, and calculate the forwarding path and the reserved transmission time slot on the path.

[0022] Preferably, after discovering a new topic, the DDS server automatically allocates a dedicated multicast IP address to each topic through a multicast address conversion mechanism, and the multicast IP address is automatically converted into a multicast MAC address according to an IP to MAC conversion rule when passing through the network card.

[0023] Preferably, in the subsequent data transmission process, the TSN switch uses VLAN tags and multicast MAC addresses to identify the DDS data stream, thereby completing the forwarding and scheduling of Ethernet frames carrying mission-critical data;

[0024] The VLAN tag in the Ethernet frame includes the VLAN ID set by the DDS user through VLANQoS and the transmission priority information of the TransportPriorityQoS setting topic.

[0025] Preferably, the DDS server extracts DDS stream information including unicast locator information of DDS publishers and subscribers, and QoS information that can represent DDS stream attributes and transmission requirements from the discovery message sent by the DDS client, maps the extracted structural stream information into a DDS stream information structure, and sends it to the TSN controller.

[0026] Preferably, QoS information that can represent DDS flow attributes and transmission requirements is encapsulated in a parameter list of the outgoing message;

[0027] The QoS information that can represent the DDS stream attributes and transmission requirements includes the cycle of each data release by the publisher, the data transmission priority, the data load size, the earliest time when the data is sent in a cycle, the latest time when the data is sent in a cycle, the jitter between the actual time when the data is sent and the specified time, the time when the publisher starts sending data, the VLAN used when the data is transmitted, and the maximum delay allowed from the sending to the receiving of the data.

[0028] Preferably, after receiving the publishing schedule, the DDS server indexes the discovery message data of the corresponding publisher in the discovery database according to its topic, and fills the publishing time in the received json file into the member corresponding to the time when the publisher starts sending data in the discovery message, and then sends the discovery message back to the corresponding publisher to configure the start publishing time.

[0029] Preferably, the TSN controller stores the L2 forwarding table and the gating list as a YANG model, and transmits them to the TSN switch via a TCP / IP connection in XML form;

[0030] The YANG model of the L2 forwarding table includes the index number, destination MAC address, source port, VLAN ID, and destination port information necessary for configuring an item in the routing table;

[0031] The YANG model of the gated list includes the ports required to configure the time-aware shaper on the TSN switch and the index, duration and gated switch status information of each GCL on the port.

[0032] Preferably, the method further includes: explicitly controlling the forwarding behavior of the multicast frame when passing through the TSN switch through a multicast spanning tree, wherein the multicast tree takes the node where the publisher is located as the root node, passes through the internal nodes representing the TSN switch in the middle, and finally reaches the leaf nodes where all subscribers are located; the TSN controller calculates a multicast tree that meets the requirements through a routing scheduling algorithm, and then converts the multicast tree into a configuration of an L2 forwarding table and sends it to the TSN switch.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1) The present invention proposes an automatic integration and configuration architecture and method of DDS and TSN that can be used in various scenarios such as the Internet and industry based on a software-defined network model. The architecture can realize automatic DDS traffic perception, forwarding and scheduling calculation and TSN system configuration before DDS transmits data, solving the problems of low efficiency, poor flexibility and complex configuration of manual integration of DDS and TSN.

[0035] 2) The present invention uses a centralized client-server discovery mode and a DDS server as a centralized user configuration module to realize automatic collection of DDS transmission demand information. This automatic collection mechanism makes full use of the dynamic discovery mechanism of DDS itself. The DDS server can extract DDS traffic information by parsing the received discovery message. There is no need to develop a special user-network interaction protocol, thus avoiding a substantial increase in the amount of protocol stack code.

[0036] 3) The present invention solves the problem of TSN system's difficulty in identifying DDS data streams by using a multicast mechanism to transmit DDS data. TSN can identify DDS data streams only by relying on VLAN and exclusive multicast MAC addresses in the data link layer, effectively reducing the difficulty of integration.

[0037] 4) The present invention makes full use of the extensible characteristics of parameter list members in RTPS messages, and expresses traffic attributes and transmission requirements to the DDS server by defining a series of DDS QoS policies and encapsulating them into the parameter list in the discovery message during the discovery message construction phase.

[0038] 5) The present invention implements dynamic configuration of TSN switches by sending messages containing YANG model configuration information, ensuring the reliability and efficiency of the configuration process and solving the problem of complex manual configuration.

[0039] 6) The present invention realizes the dynamic interaction between DDS and TSN by establishing a request-response mechanism between the DDS server and the TSN controller, integrating the two independent protocols.

[0040] 7) The present invention adopts the time-aware publishing mechanism of the DDS publisher, and solves the alignment problem of the DDS issuance time and the scheduling time window reserved in the TSN by controlling the publishing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Configure architecture for automated integration of DDS and TSN based on software-defined networking;

[0042] Figure 2 Flowchart for configuring automated integration of DDS and TSN;

[0043] Figure 3 This is a schematic diagram of the DDS stream identification conversion mechanism;

[0044] Figure 4 This is a schematic diagram of DDS flow information collection based on discovery messages;

[0045] Figure 5 This is a diagram of the interaction between DDS Server and TSN controller;

[0046] Figure 6 Schematic diagram of the multicast spanning tree;

[0047] Figure 7 To configure the YANG model for L2 forwarding table;

[0048] Figure 8 To configure the gate list YANG model;

[0049] Fig. 9 Configure the flow chart for DDS publishing moment. DETAILED DESCRIPTION

[0050] 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 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 should fall within the scope of protection of the present invention.

[0051] Example

[0052] This embodiment proposes an automatic integrated configuration architecture of DDS and TSN based on a centralized software-defined network model. Figure 1 As shown in the figure, the architecture consists of three parts: application layer, control layer, and data layer. The application layer includes the publisher and subscriber of DDS, the control layer includes the centralized user configuration module and the centralized network configuration module, and the data layer includes the end system where the DDS application is deployed and the TSN switch in the network.

[0053] The functions of each part of the architecture are as follows:

[0054] The DDS Client application is responsible for publishing and subscribing to user data. It needs to periodically send discovery messages containing its own information to the DDS Server and receive discovery messages from the DDS Server.

[0055] As a centralized user configuration module, DDS Server is responsible for the interaction between DDS and TSN systems. It completes the three major functions of multicast transmission address conversion, traffic information collection and release time configuration by collecting, processing and forwarding discovery messages.

[0056] As a centralized network configuration module, the TSN controller is responsible for routing and scheduling calculations. Based on the calculation results, it generates the L2 forwarding table, gating list, and release schedule. It also completes the configuration of the DDS through the northbound interface in the form of sending messages and completes the configuration of the TSN switch through the southbound interface.

[0057] The TSN switch is responsible for forwarding and processing multicast DDS messages according to the locally configured L2 forwarding table and gating list to meet the DDS requirement for bounded latency.

[0058] Next, based on the above-mentioned DDS and TSN automatic integration configuration architecture, this embodiment provides a method for DDS and TSN automatic integration configuration, such as Figure 2 As shown, including:

[0059] S1. After discovering a new topic Topic, DDS Server will allocate a dedicated multicast locator for it for subsequent data transmission. The DDS publisher will use the multicast address specified in this multicast locator to send data, and the DDS subscriber will listen to the data at this multicast address. The purpose of multicast address conversion is to achieve the decoupling of the destination MAC address in the DDS data message and the MAC address of the subscriber's end system. The TSN system can identify the DDS flow based on the destination MAC address in the message, so as to control and schedule its path.

[0060] Figure 3 Schematic diagram of DDS stream identification conversion mechanism.

[0061] When DDS key data is encapsulated into frames and enters the Layer 2 network for transmission, TSN must be able to identify these flows with deterministic transmission requirements before they can perform path control and real-time scheduling. In order to achieve efficient TSN identification of DDS streams, the present invention uses a DDS multicast mechanism to convert the DDS stream so that it can be identified. The present invention uses a combination of VLAN Tag and multicast MAC address in Ethernet frames to identify DDS data streams under different Topics.

[0062] For VLAN Tag settings, DDS users can set VLAN ID through VLANQoS and set the transmission priority of Topic through TransportPriorityQoS. In addition, the mapping rules of the host network card priority need to be set in advance. When DDS data is sent through the network card, the previously set VLAN ID will be automatically added, and the transmission priority in TransportPriorityQoS will be mapped to the VLAN PCP field according to the priority mapping rules.

[0063] The addition of multicast MAC addresses is the core of the DDS stream identification mechanism, which requires the cooperation of the DDS Server to complete. DDS adopts unicast mode for data transmission by default, and the destination IP and MAC address in the DDS message are the IP and MAC address of the host network card where the subscriber is located. However, this destination address tightly coupled with the network card cannot uniquely identify a certain DDS data stream, and the unicast transmission mode will lead to a decrease in efficiency under one-to-many conditions. For this reason, the present invention uses a DDS multicast transmission mechanism. The DDS Server will automatically assign a dedicated multicast IP address to each Topic. The multicast IP address will be automatically converted to a multicast MAC address according to the IP to MAC conversion rules when passing through the network card. In this way, the TSN switch can identify the DDS stream based on the information of the data link layer alone, without the need for higher-level message parsing.

[0064] S2. After receiving the discovery message sent by the DDS Client, the DDS Server extracts the Unicast locator information of the DDS publisher and subscriber, as well as the QoS information that can represent the DDS stream attributes and transmission requirements, and maps this information into the DDS stream information structure. The DDS stream information collection based on the discovery message is shown in the following figure. Figure 4 shown.

[0065] When using TSN, in order to achieve deterministic transmission of key data streams, it is necessary to reserve a suitable forwarding path and the transmission time slot on the path through calculation before transmission. Therefore, before configuring the TSN system, it is necessary to collect information such as the associated Topic, source node, destination node, cycle, VLAN ID, priority, load size, offset and jitter, maximum allowed delay, multicast transmission address, etc. of the DDS data stream. The present invention adopts the Client-Server discovery mode and innovatively uses the DDS Server as the CUC, so that the discovery mechanism of DDS can be used as the user-network interface in the centralized configuration model to achieve the purpose of information collection.

[0066] The following QoS parameters are defined for DDS users to set the attributes and transmission requirements of application layer data:

[0067] (1) DeadlineQoS

[0068] Parameter Id Parameter members Parameter length Parameter meaning 0x0023 period 8 bytes Indicates the period during which the publisher publishes data

[0069] (2)TransportPriorityQoS

[0070] Parameter Id Parameter members Parameter length Parameter meaning 0x0049 priority 8 bytes Indicates the priority of data during transmission

[0071] (3)PayloadQoS

[0072] Parameter Id Parameter members Parameter length Parameter meaning 0x8007 payload 8 bytes Indicates the payload size of the data

[0073] (4)TimeAwareQoS

[0074]

[0075] (5) VLAN QoS

[0076] Parameter Id Parameter members Parameter length Parameter meaning 0x8009 id 4 bytes Indicates the VLAN used when transmitting data

[0077] (5)LatencyBudgetQoS

[0078]

[0079] The QoS described above will be encapsulated into the ParameterList part of the discovery message during the discovery phase of the DDS Client. After receiving the discovery message about the DataWriter, the EDPPUBListener of the DDS Server will extract the WriterProxyData from it after deserialization, which contains the associated topic, the IP address of the host where it is located, and various QoS. EDPPUBListener will use the topic as the index, store the unicast locator in the source IP, and then map the various QoS of the DataWriter to various attributes of the stream and store them in DDSStreamInfo. EDPSUBListener is responsible for collecting the IP address of the host where the DataReader is located and adding it to the destination IP. In addition, because the multicast transmission mechanism is used, the allocated multicast address also needs to be stored.

[0080] S3, DDS Server stores the DDS stream information in a json format file after obtaining it, and sends the json file to the TSN controller through a TCP / IP connection to request dynamic configuration. Figure 5 As shown in the figure, the interaction between DDS Server and TSN controller is shown.

[0081] S4. After receiving the request from the DDS Server, the TSN controller will generate TSN flow information based on the global network topology information and DDS flow information, and then input the TSN flow into the routing and scheduling algorithm. If the scheduling is successful, the routing algorithm will output the L2 forwarding table for path control of TSN, and the scheduling algorithm will output the gating list and the schedule for the DDS publisher to start sending data. The TSN controller will transmit the publishing schedule to the DDS Server in the form of a json file through the TCP / IP connection previously established with the DDS Server as a response. For the L2 forwarding table and gating list, the TSN controller stores them as YANG models and transmits them to the TSN switch in the form of XML through a TCP / IP connection.

[0082] During the generation of the TSN stream, the TSN controller needs to map the source IP address and the destination IP address in the DDS stream information to nodes in the network based on the network topology information.

[0083] In order to solve the forwarding problem of multicast streams, this embodiment constructs a multicast spanning tree to explicitly control the forwarding behavior of multicast frames when they pass through the switch. Figure 6 As shown in the figure, a multicast tree consists of several nodes, each of which stores its own parent node and child node, thus linking into a tree structure. The multicast tree takes the node where the publisher is located as the root node, passes through the internal nodes representing the switch in the middle, and finally reaches the leaves where all subscribers are located. The routing algorithm of the TSN controller will calculate a multicast tree that meets the requirements, and then convert the multicast tree into the configuration of the L2 forwarding table and send it to the switch, so that the message can enter the switch from a switch port and be sent out from the switch from one or more ports configured in the forwarding table.

[0084] like Figure 7 As shown, the YANG model of the L2 forwarding table contains the index number, destination MAC address, source port, VLAN ID, and destination port information required to configure an item in the routing table.

[0085] like Figure 8 As shown in Figure 1, the YANG model of the gate list contains the ports required to configure the time-aware shaper on the TSN switch and the index, duration, and gated switch status information of each GCL on the port.

[0086] S5. After receiving the reply from the TSN controller, the DDS Server extracts the sending time of each Topic and forwards the time to the corresponding DDS publisher through the discovery message, thereby completing the time configuration for the DDS publisher to start sending data.

[0087] After receiving the configuration about the publishing time, the DDS Server will index the discovery message data of the corresponding publisher in the DiscoveryDatabase according to its Topic, and fill the publishing time in the received json file into the scheduled transmit offset member of TimeAwareQoS in the discovery message, and then send the discovery message back to the corresponding publisher to configure its start publishing time.

[0088] S6. After receiving the discovery message with the start publishing time set from the DDS Server, the DDS publisher completes the publishing configuration of the local publishing time and enters the waiting state, and starts to send data periodically after the configured time arrives.

[0089] like Fig. 9 As shown, after receiving the discovery message, the publisher will filter the GUID in the discovery message. If it is consistent with the local GUID, it will enter the publishing time configuration process. The publisher's PubListener will call the on_transmit_offset_configuration() method to set the firstConfigurated_ flag and extract the scheduled transmit offset in TimeAwareQoS to set the start_point_.

[0090] This embodiment adds conditional judgment before the publisher sends data to realize the time perception capability of the DDS publisher. Data will be sent only if the firstConfigurated_ flag is true and the current time is greater than start_point_.

[0091] S7. After receiving the configuration message containing the YANG model, the TSN switch extracts the configuration information from it and completes the dynamic configuration of the local L2 forwarding table and gating list.

[0092] S8. At this point, the entire automatic integration and configuration of DDS and TSN before data transmission is completed. The DDS publisher will start to send data periodically at the required time, and the messages entering TSN will be forwarded and scheduled according to the pre-configuration to ensure the real-time arrival of DDS data at the DDS subscriber.

[0093] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A DDS and TSN automated integrated configuration architecture, including an application layer, a control layer and a data layer, characterized in that: The application layer includes publishers and subscribers of DDS, the control layer includes a DDS server as a centralized user configuration module and a TSN controller as a centralized network configuration module, and the data layer includes TSN switches in the end system and network where the DDS application is deployed; The TSN controller establishes a connection with the DDS server, and the DDS server sends the collected information to the TSN controller through the connection to request a reserved transmission time slot of network resources; The TSN controller outputs an L2 forwarding table, a gating list and a publishing schedule that meet the requirements of multicast transmission through a routing scheduling algorithm; wherein the L2 forwarding table and the gating list are sent to the TSN switch for configuration, and the publishing schedule is replied to the DDS server as a response to the request, and the DDS server dynamically configures the time when the publisher starts to send data; The TSN switch is used to forward the multicast DDS message according to the locally configured L2 forwarding table and gating list.

2. A DDS and TSN automated integration configuration method, characterized in that: Applying the architecture of claim 1, the method comprises: After the DDS server discovers a new topic, it assigns it a dedicated multicast locator for subsequent data transmission; The DDS server extracts the DDS stream information from the discovery message sent by the DDS client, and sends the DDS stream information to the TSN controller to request dynamic configuration; After receiving the request sent by the DDS server, the TSN controller generates TSN flow information based on the global network topology information and the DDS flow information, and inputs the TSN flow information into the routing scheduling algorithm. The routing scheduling algorithm outputs the L2 forwarding table for path control of the TSN, the gating list, and the publishing schedule for the DDS publisher to start sending data, and then transmits the publishing schedule to the DDS server as a reply, and sends the L2 forwarding table and the gating list to the TSN switch; After receiving the reply from the TSN controller, the DDS server extracts the sending time of each topic and forwards the sending time to the corresponding DDS publisher through the discovery message; After receiving the discovery message with the start publishing time set from the DDS server, the DDS publisher completes the publishing configuration of the local publishing time and enters the waiting state, and starts to send data periodically after the configured time arrives; After receiving the configuration message containing the YANG model, the TSN switch completes the dynamic configuration of the local L2 forwarding table and gating list based on the extracted configuration information.

3. The method according to claim 2, characterized in that Based on the client-server discovery mode, the discovery mechanism of DDS is used as the user-network interface to collect the automatic collection of DDS stream transmission information, and the forwarding path and the reserved transmission time slot on the path are calculated.

4. The method according to claim 2, characterized in that: After the DDS server discovers a new topic, it automatically allocates a dedicated multicast IP address to each topic through a multicast address conversion mechanism. The multicast IP address is automatically converted to a multicast MAC address according to the IP to MAC conversion rule when passing through the network card.

5. The method according to claim 4, characterized in that In the subsequent data transmission process, the TSN switch uses VLAN tags and multicast MAC addresses to identify the DDS data stream, thereby completing the forwarding and scheduling of Ethernet frames carrying mission-critical data; The VLAN tag in the Ethernet frame includes the VLAN ID set by the DDS user through VLANQoS and the transmission priority information of the TransportPriorityQoS setting topic.

6. The method according to claim 2, characterized in that The DDS server extracts DDS stream information including unicast locator information of DDS publishers and subscribers, and QoS information that can represent DDS stream attributes and transmission requirements from the discovery message sent by the DDS client, maps the extracted structural stream information into a DDS stream information structure, and sends it to the TSN controller.

7. The method according to claim 6, characterized in that During the discovery phase of the DDS client, the QoS information that can represent the DDS flow attributes and transmission requirements is encapsulated in the parameter list of the outgoing message; The QoS information that can represent the DDS stream attributes and transmission requirements includes the cycle of each data release by the publisher, the data transmission priority, the data load size, the earliest time when the data is sent in a cycle, the latest time when the data is sent in a cycle, the jitter between the actual time when the data is sent and the specified time, the time when the publisher starts sending data, the VLAN used when the data is transmitted, and the maximum delay allowed from the sending to the receiving of the data.

8. The method according to claim 7, characterized in that After receiving the publishing schedule, the DDS server indexes the discovery message data of the corresponding publisher in the discovery database according to its topic, and fills the publishing time in the received json file into the member corresponding to the time when the publisher starts sending data in the discovery message, and then sends the discovery message back to the corresponding publisher to configure the start publishing time.

9. The method according to claim 2, characterized in that: The TSN controller stores the L2 forwarding table and the gating list as a YANG model and transmits them to the TSN switch via a TCP / IP connection in XML format; The YANG model of the L2 forwarding table includes the index number, destination MAC address, source port, VLAN ID, and destination port information necessary for configuring an item in the routing table; The YANG model of the gated list includes the ports required to configure the time-aware shaper on the TSN switch and the index, duration and gated switch status information of each GCL on the port.

10. The method according to claim 2, characterized in that The method also includes: explicitly controlling the forwarding behavior of the multicast frame when passing through the TSN switch through a multicast spanning tree, wherein the multicast tree takes the node where the publisher is located as the root node, passes through the internal nodes representing the TSN switch in the middle, and finally reaches the leaf nodes where all subscribers are located; the TSN controller calculates a multicast tree that meets the requirements through a routing scheduling algorithm, and then converts the multicast tree into a configuration of an L2 forwarding table and sends it to the TSN switch.

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