Reliable data transmission method based on unidirectional cross-network

Abstract

The invention relates to the technical field of data transmission, in particular to a reliable data transmission method based on one-way cross-network, which comprises the following steps: S1, transmission strategy making: based on the current network communication condition, sorting the sending requirements of various data, and making corresponding transmission strategies for different data types of each data sender; s2, transmission state monitoring: data transmission management centers are arranged in the two network systems respectively, and the states of the networks are collected, sorted and published; s3, data cross-network transmission: the sending node obtains monitoring information of a transmission state in the network, and executes corresponding transmission by adopting an initial default path according to the data types sorted in the step S1; and S4, preferentially updating the transmission path: selecting an optimal path by adopting a dijkstra algorithm, and setting the optimal path as a new default path. According to different transmission requirements of data on real-time performance, reliability and the like, type codes are compiled and generated, and corresponding transmission strategies are formulated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data transmission, in particular to a reliable data transmission method based on one-way cross-network. BACKGROUND

[0002] With the rapid development of network information technology and the continuous advancement of informationization construction, various units, departments and industries have gradually established network information systems. In order to ensure network information security, physical isolation security measures of network information systems are widely used. For some high-value internal networks with high security requirements, the internal network and external network are physically isolated at present, such as the internal network and external network of government e-government, the internal network and external network of the financial industry, the internal network and external network of the aerospace field, etc.

[0003] For data exchange between physically isolated network systems, optical disc ferry, network gate ferry and one-way transmission technology are mainly used. Optical disc ferry and network gate ferry have problems such as slow transmission speed and insufficient security strength. In departments with high requirements for network isolation and cross-network exchange efficiency, one-way transmission isolation systems are gradually used for cross-network data transmission. The one-way transmission isolation system adopts a "front and rear + one-way" mode, which is composed of front servers, rear servers and one-way isolation transmission units, and provides one-way loop-free security for data transmission through physical isolation.

[0004] Due to the increasing frequency of system data exchange and transmission between different networks, especially in departments that have established internal and external networks, the real-time and security requirements for data transmission are often high. A one-way transmission facility cannot meet the high-frequency data cross-network transmission of multiple sub-departments distributed in a wide range. Therefore, they gradually adopt the method of establishing multiple one-way transmission nodes in different regions within the department to meet the growing demand for internal and external network cross-network data exchange. However, the construction cost of single-point transmission equipment is high, and the maintenance requirement is high, which cannot support excessive construction. How to more efficiently use these cross-network devices to complete the data exchange between network systems has gradually become a problem that needs to be solved. SUMMARY

[0005] The present application aims to provide a reliable data transmission method based on one-way cross-network to solve the problems raised in the background.

[0006] To achieve the above purpose, the present application provides the following technical scheme: A reliable data transmission method based on one-way cross-network, comprising the following steps: S1, transmission strategy formulation: based on the current network communication situation, sort out the sending requirements of various data, and formulate corresponding transmission strategies for different data types of each data sender; S2, transmission state monitoring: two network systems are respectively provided with data transmission management centers to collect, arrange and release the state of the network; S3, data cross-network transmission: the sending node acquires the monitoring information of the transmission state in the network, and performs corresponding transmission according to the data type sorted in step S1 using the initial default path; S4, transmission path optimization update: the dijkstra algorithm is used to select the optimal path, and the optimal path is set as the new default path.

[0007] Preferably, step S1 specifically includes: S11, network connection establishment: Initialize the inter-node connection relationship involved in cross-network exchange association to the data connection information table, and update the related information in the table when the inter-node connection relationship is updated; S12, data transmission type planning: According to different data transmission requirements, the transmission type is divided into time-sensitive type, reliable type, ordinary type and composite type of time-sensitive type and reliable type, and each type of data is allocated a transmission priority level, and finally a transmission type code of each data type is formed; When the data is transmitted, the transmission strategy is determined according to the transmission type code, and the sending order is determined according to the transmission priority; S13, default path planning: Sort each data sending point, set an initial default path for each data type in it, and normally preferentially select the initial default path when data is sent.

[0008] Preferably, step S2 specifically includes: S21, link state collection: Through ICMP, Netstat tool to realize data receiving, relaying, IP connectivity of cross-network node device, port reachability detection, and collection of delay, Time_WAIT quantity; Read the working state of the sending, relaying, cross-network node device through SNMP tool, including traffic, packet error rate, CPU / memory utilization.

[0009] S22, collection of reliable data transmission conditions: Batch sending of reliable data is performed at the data sending node, and a sending list is formed when data is sent, recording the required sending file identifier, size, checksum, sending time and sender information; Each relay node and cross-network node forms a forwarding list for the reliable data it forwards, recording the forwarded file identifier, size, checksum, forwarding time and forwarder information; The data receiver must establish a receiving list for the received reliable data, store file identification, size, check code, receiving time, receiver information, and receive sending list and forwarding list information sent by the sending node, relay node and cross-network node, and aggregate to form complete transmission original information of the reliable data; In the case that the network environment is safe and controllable, the file check code is selected as MD5 value to realize fast file check, and in the case that the network environment is not controllable and the file security requirement is high, SHA-256 or higher security check code is selected; S23, monitoring information cross-network distribution The collected link state information and reliable data transmission condition are aggregated and arranged by the data transmission management center, and are interactively published through the two-network one-way cross-network equipment.

[0010] Preferably, the step S3 specifically comprises: S31, basic information publishing: the data transmission management center publishes state information and default path information; S32, sending path selection: the sending node executes different transmission path selection strategies according to data types; S33, data transmission execution: each transmission node executes different data transmission strategies according to data types.

[0011] Preferably, the step S31 specifically comprises: S311, state monitoring information synchronization: the sending node acquires state information of the sending node, relay node and cross-network node available for connection and use; S312, default path synchronization: each node synchronizes the default path of different data types, and the basic information is a four-tuple [data type, sender, previous node, subsequent node].

[0012] Preferably, the step S32 specifically comprises: S321, for time-sensitive data or composite data with time-sensitive requirement, full-path selection is performed for optimal sending; S322, for ordinary data and reliable data, the default path is preferentially selected for transmission, and when the default path fails, full-path selection is performed for optimal sending.

[0013] Preferably, the step S33 specifically comprises: S331, data is transmitted according to the selected transmission path, the sending node records sending information to form a sending list, and sends the sending list to the receiving node and the data transmission management center; S332, the relay node and the cross-network front node forward data according to data priority, and the data with high priority is preferentially forwarded; S333, the cross-network front-end node and the cross-network back-end node record the data forwarding information to form a cross-network forwarding list and send it to the data transmission management center; S334, the receiving node receives the sending list, records the received data information to form a receiving list and sends it to the data transmission management center; S335, the time-sensitive and general type of data completes data reception, and the reliable type of data or the composite type of data with reliability requirements checks whether the data transmission is lost or damaged after sending is completed.

[0014] Preferably, step S335 specifically includes: S3351, the receiving node needs to compare and check the sending data list and the receiving data list information to obtain the data transmission loss or damage condition; S3352, the receiving node determines that the data has been normally received, and sends the receiving list to the sender; if there is data loss or damage, the receiving node initiates a retransmission application as needed; S3353, the sending node receives the retransmission request and retransmits as needed, and repeats steps S331-S335; the sending node receives the acceptance list sent by the receiving node and completes the transmission loop.

[0015] Preferably, step S4 specifically includes: S41, according to the cross-network transmission packet loss rate obtained by comparing the cross-network forwarding list information received by the cross-network front-end and back-end nodes and the device packet error rate obtained by the SNMP monitoring tool within a period of time, the average transmission success rate of the transmission path containing the cross-network device and the transmission path not containing the cross-network device is obtained respectively . .

[0016] S42, according to the transmission delay obtained by the ICMP tool and the cross-network transmission time obtained by comparing the cross-network forwarding list information received by the cross-network front-end and back-end nodes, the average response time of the transmission path containing the cross-network device and the transmission path not containing the cross-network device is obtained respectively i . ; S43, according to the state information collected by the link state tool on the cross-network device front-end node, the current cross-network device queuing condition is obtained, and the cross-network device busy rate of the transmission path is calculated by combining the transmission capacity of the cross-network device : : (1); (2); In formula (1), For the expected waiting time, n is the total number of queued files to be transmitted in the cross-network front-end machine, j is the jth queued file to be transmitted in the cross-network front-end machine, For the size of the queued file, For the transmission bandwidth of the one-way cross-network transmission device; In formula (2), For the waiting time threshold; S43, the above factors are calculated by linear weighting method to obtain the distance weight of the transmission path of the transmission path is: (3); In formula (3), k1, k2, k3 are weight coefficients, when the path does not contain cross-network equipment Take 0; The transmission path with the smallest distance weight is taken as the optimal path, and is set as the new default path.

[0017] Compared with the prior art, the beneficial effects of the present application are: The reliable data transmission method based on one-way cross-network provided by the present application is based on a multi-point one-way cross-network transmission scene, generates type codes according to different transmission requirements of data such as real-time performance and reliability, and formulates corresponding transmission strategies. Transmission management centers are respectively arranged in different network systems to realize network state collection, arrangement and cross-network publishing. In the data transmission process, path selection and data transmission are performed according to the transmission strategy (the influence factor of the cross-network equipment capability is added in the path selection). Since the one-way transmission cross-network equipment only provides one-way loop-free data transmission, the data sender and receiver on different network systems cannot guarantee the reliable transmission of data through the handshake response and other methods of the network, and cannot perform automatic retransmission in the case of data loss or damage. Therefore, in order to ensure transmission reliability, the transmission process state collection, transmission list comparison analysis and data retransmission mechanism are designed to complete the cross-network transmission reliable closed loop of data.

[0018] In addition, under the one-way cross-network transmission mode, the network states in different network systems cannot be synchronized in real time. In this case, frequent dynamic path selection cannot necessarily obtain the best transmission path, therefore, the present application sets a default path for each data type and updates it regularly by using dijkstra algorithm, so as to ensure the relative stability of the data transmission path within a period of time. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the overall flowchart of the reliable data transmission method based on one-way cross-network in the embodiment of the present application; Figure 2 is the data transmission process schematic diagram provided in the embodiment of the present application;​ Figure 3 A schematic diagram of a data transmission link provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0021] Figure 1 A whole flowchart of a reliable data transmission method based on one-way cross-network provided in the present application is shown. As shown in the figure, an embodiment of the present application provides a reliable data transmission method based on one-way cross-network, comprising the following steps: Figure 1 S1, transmission strategy making: based on current network communication situation, the sending requirements of various data are sorted out, and corresponding transmission strategies are made for different data types of each data sender; S2, transmission state monitoring: data transmission management centers are respectively arranged in two networks, and the state of the network is collected, sorted and published; S3, data cross-network transmission: the sending node obtains the monitoring information of the transmission state in the network, and performs corresponding transmission according to the initial default path of the data type sorted in step S1; S4, transmission path optimal update: dijkstra algorithm is used to select the optimal path, and the optimal path is set as the new default path.

[0022] In an embodiment of the present application, step S1 specifically comprises: S11, network communication situation establishment: The inter-node communication relationship of all networks involved in cross-network exchange association is initialized into a data communication information table, and when the inter-node communication relationship is updated, the related information in the table needs to be updated; S12, data transmission type planning: According to different requirements of data transmission, the transmission types are divided into time-sensitive type, reliable type, ordinary type and composite type of time-sensitive type plus reliable type, and transmission priority levels are allocated to each type of data, so as to finally form transmission type codes of each type of data; When data is transmitted, the transmission strategy is determined according to the transmission type code, and the sending order is determined according to the transmission priority; ​Specifically, time-sensitive data requires real-time transmission, and transmission delay needs to be as small as possible. When transmitting such data, the shortest transmission path, the shortest cross-network delay, and the reduction of queuing time are often considered. Therefore, the highest transmission level is assigned to it, and it can be transmitted immediately.

[0023] High-reliability data requires no loss or damage during data transmission. When transmitting such data, a relatively stable transmission link needs to be selected, and data verification means and retransmission or reissue mechanisms need to be designed to ensure data integrity and correctness.

[0024] Ordinary data requires transmission as much as possible, and there is no special requirement for timeliness and reliability, so a lower transmission level can be assigned.

[0025] The transmission type, transmission priority and transmission type code corresponding to each data type are shown in Table 1: Table 1: Data transmission type code example

[0026] S13, default path planning: Each data sending point is sorted, and an initial default path is set for each data type in it. The initial default path is normally selected when data is sent.

[0027] In the single cross-network transmission mode, the network connection and device working state in different networks need to be forwarded through double single cross-network devices, and the real-time performance is poor. In this case, it is impossible to guarantee that the dynamic path selection can always obtain the actual optimal path. Therefore, the relative stability of the data transmission path needs to be ensured by planning the default path. The initial default path usually specifies that the data generated by a certain sub-department is transmitted through the cross-network of the network gateway belonging to the sub-department by default.

[0028] In an embodiment of the present application, step S2 specifically comprises: S21, link state collection: ICMP, Netstat tools are used to realize data transmission, relay, cross-network node device IP connectivity, port reachability detection, and to collect delay, Time_WAIT quantity; SNMP tools are used to read the working state of the transmitting, relaying, and cross-network node devices, including traffic, packet error rate, CPU / memory utilization.

[0029] S22, reliable data transmission condition collection: Reliable data is sent in batches at the data sending node. When data is sent, a sending list is formed to record the required file identifier, size, checksum, sending time, and sender information. Each relay node, cross-network node forms a forwarding list for the reliable data it forwards, recording the file identification, size, check code, forwarding time, and forwarder information of the forwarded file; The data receiver must establish a receiving list for the received reliable data, storing the file identification, size, check code, receiving time, and receiver information, and receive the sending list and forwarding list information sent by the sending node, relay node, and cross-network node, and aggregate to form the complete transmission original information of the reliable data; In the case that the network environment is safe and controllable, the file check code is selected as MD5 value to realize fast file check, and in the case that the network environment is not controllable and the requirement for file safety is high, SHA-256 or higher safety check code is selected; S23, cross-network distribution of monitoring information The collected link state information and reliable data transmission situation are aggregated and arranged by the data transmission management center, and are interactively published through the unidirectional cross-network equipment between the two networks.

[0030] The sending node obtains the monitoring information of the transmission state in the network, and executes corresponding transmission according to the data types sorted in the step of formulating the transmission strategy. The corresponding processing of the reliable data needs to be supplemented in the data transmission process. Since the unidirectional cross-network equipment only provides unidirectional and loopless data transmission, the data sender and receiver on different networks cannot guarantee the reliable transmission of data through the handshake response and other ways of the network, and cannot automatically retransmit in the case of data loss or damage. In the case of failure of the cross-network equipment or data transmission relay node, it is also not easy to find. Therefore, in order to ensure the transmission reliability, the process state of the transmission needs to be collected and monitored, and a suitable retransmission or resending mechanism needs to be designed.

[0031] Figure 2 A data transmission process diagram provided in the embodiment of the application is shown in FIG. 1. Figure 2 As shown in FIG. 1, in one embodiment of the application, step S3 specifically includes: S31, basic information publishing: the data transmission management center publishes state information and default path information; S32, sending path selection: the sending node executes different transmission path selection strategies according to the data types; S33, data transmission execution: each transmission node executes different data transmission strategies according to the data types.

[0032] In one embodiment of the application, step S31 specifically includes: S311, state monitoring information synchronization: the sending node obtains the state information of the sending node, relay node, and cross-network node available for its communication; S312, default path synchronization: each node synchronizes the default path of different data types, and the basic information is a four-tuple [data type, sender, previous node, and subsequent node].

[0033] In an embodiment of the present application, step S32 specifically includes: S321, for time-sensitive data or composite data with time-sensitive requirements, full path selection is performed for optimal transmission. S322, for ordinary type and reliable type data, default path transmission is preferentially selected, and when the default path fails, full path selection is performed for optimal transmission.

[0034] In an embodiment of the present application, step S33 specifically includes: S331, transmitting data according to the selected transmission path, recording transmission information of the sending node to form a transmission list, and sending to the receiving node and the data transmission management center; S332, the relay node and the cross-network front node forward data according to the data priority, and the data with high priority is preferentially forwarded; S333, the cross-network front node and the cross-network back node record data forwarding information to form a cross-network forwarding list and send to the data transmission management center; S334, the receiving node receives the transmission list, records the received data information to form a receiving list and sends to the data transmission management center; S335, the time-sensitive and ordinary type data completes data reception, and the reliable type data or the composite data with reliability requirements completes transmission, and then the data transmission loss or damage is checked.

[0035] In an embodiment of the present application, step S335 specifically includes: S3351, the receiving node needs to compare and check the transmission data list and the receiving data list information to obtain the data transmission loss or damage; S3352, the receiving node determines that the data has been normally received, and sends the receiving list to the sender; if there is data loss or damage, the receiving node initiates a retransmission application as needed; S3353, the sending node receives the retransmission request and retransmits as needed, and repeats steps S331-S335; the sending node receives the acceptance list sent by the receiving node, and completes the transmission loop.

[0036] Figure 3 A data transmission link diagram is provided in an embodiment of the present application. As shown in Figure 3As shown, the network transmission link should be divided into 4 segments for calculation, which are sending node S-relay forwarding node M1, relay forwarding node M1-cross-network front-end node C1, cross-network front-end node C1-cross-network back-end node C2, cross-network back-end node C2-receiving node R.

[0037] In the case of network reachability, the calculation of the path distance value between transmission nodes needs to consider factors such as transmission reliability, response time, node failure rate, cross-network device transmission capacity, and cross-network device busy rate. It should be noted that the reliability and response time on the transmission path without cross-network devices can be obtained through ICMP, SNMP and other network monitoring tools, and the reliability and response time on the transmission path between cross-network devices need to be calculated from the cross-network forwarding list information recorded during data transmission.

[0038] In an embodiment of the present application, the data transmission management center periodically aggregates and statistics the data transmission and reception recorded by various types of data sending nodes and receiving nodes within a period of time, combines the network node and cross-network facility monitoring state within the period of time to evaluate and analyze the transmission link, and adjusts the default data transmission path. Specifically, step S4 specifically includes: S41, according to the cross-network transmission packet loss rate obtained by comparing the device packet error rate obtained by the SNMP monitoring tool and the cross-network forwarding list transmission and reception information reported by the cross-network front-end and back-end nodes, the average transmission success rate of the transmission path with and without cross-network devices is obtained respectively ; S42, according to the cross-network transmission time length obtained by comparing the transmission delay obtained by the ICMP tool and the cross-network forwarding list transmission and reception information reported by the cross-network front-end and back-end nodes, the average response time of the transmission path with and without cross-network devices is obtained respectively i ; S43, according to the state information collected by the link state tool on the cross-network device front-end node, the current cross-network device queuing situation is obtained, and the cross-network device busy rate of the transmission path is calculated : (1); (2); In formula (1), is the expected waiting time, n is the total number of queued files to be transmitted in the cross-network front-end, j is the jth file to be transmitted in the cross-network front-end, is the file size, is the one-way cross-network transmission device transmission bandwidth; ​​​In equation (2), This is the waiting time threshold; The link status tool is a status inspection tool developed for cross-network devices. It provides a device transmission status query interface by the cross-network transmission device. Based on the number and size of the current data to be sent returned by the interface, the estimated queuing time is calculated by dividing by the one-way transmission bandwidth of the cross-network transmission device. S43. Calculate the transmission path by applying the linear weighting method to the above factors. Distance weight for: (3); In equation (3), k1, k2, and k3 are weighting coefficients, which are used when the path does not contain cross-network devices. Set to 0; Distance weight Minimum transmission path As the optimal path, and set as the new default path.

[0039] This invention provides a reliable data transmission method based on one-way cross-network transmission. It generates type codes and formulates corresponding transmission strategies based on different data transmission requirements such as real-time performance and reliability. Transmission management centers are set up in different network systems to collect, organize, and distribute network status across networks. During data transmission, path selection and data sending / receiving are performed according to the transmission strategy (the capability of cross-network devices is considered during path selection). Since one-way cross-network devices only provide one-way, loop-free data transmission, data senders and receivers in different network systems cannot guarantee reliable data transmission through network handshakes or other methods. Automatic retransmission is not possible in case of data loss or corruption. Therefore, to ensure transmission reliability, mechanisms such as transmission process status collection, sender / receiver list comparison and analysis, and data retransmission are designed to complete a reliable closed loop for cross-network data transmission.

[0040] Furthermore, in the unidirectional cross-network transmission mode, the network status in different network systems cannot be synchronized in real time. In this case, frequent dynamic path selection may not necessarily obtain the best transmission path. Therefore, this invention sets a default path for each data type and uses the Dijkstra algorithm to update it periodically to ensure the relative stability of the data transmission path over a period of time.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reliable data transmission method based on one-way cross-network transmission, characterized in that, Includes the following steps: S1. Transmission strategy formulation: Based on the current network connectivity, sort out the transmission requirements of various types of data, and formulate corresponding transmission strategies for different data types of each data sender; S2. Transmission Status Monitoring: Data transmission management centers are set up in both network systems to collect, organize, and publish the network status. S3. Cross-network data transmission: The sending node obtains monitoring information on the transmission status in the network and performs the corresponding transmission according to the data types sorted out in step S1 using the initial default path. S4. Optimal transmission path update: The Dijkstra algorithm is used to select the optimal path and set the optimal path as the new default path.

2. The reliable data transmission method based on one-way cross-network transmission according to claim 1, characterized in that, Step S1 specifically includes: S11. Establishment of network connectivity: Initialize the communication relationships between nodes in all network systems involved in the cross-network system exchange association into the data communication information table. When the communication relationships between nodes are updated, the relevant information in this table must be updated. S12. Data transmission type planning: Based on different data transmission requirements, transmission types are divided into time-sensitive, reliable, ordinary, and composite types of time-sensitive and reliable types. Transmission priority levels are assigned to each type of data, ultimately forming a transmission type code for each data type. When data is transmitted, the transmission strategy is determined according to the transmission type encoding, and the transmission order is determined according to the transmission priority. S13, Default Path Planning: For each data sending point, an initial default path is set for each data type. Under normal circumstances, the initial default path is selected first when sending data.

3. The reliable data transmission method based on one-way cross-network transmission according to claim 2, characterized in that, Step S2 specifically includes: S21. Link Status Acquisition: The ICMP and Netstat tools are used to detect the IP connectivity and port reachability of data transmission and reception, relay, and cross-network node devices, and to collect latency and the number of Time_WAITs. Use SNMP tools to read the working status of transceiver, relay, and cross-network node devices, including traffic, packet error rate, and CPU / memory utilization. S22. Collection of reliable data transmission status: Reliable data is sent in batches at the data sending node. A sending list is generated during data sending, recording the file identifier, size, checksum, sending time, and sender information to be sent. Each relay node and cross-network node forms a forwarding list for the reliable data it forwards, recording the file identifier, size, checksum, forwarding time, and forwarder information of the forwarded file; The data receiver must establish a reception list for the received reliable data, storing file identifier, size, check code, reception time, and receiver information; and receive the transmission list and forwarding list information sent by the sending node, relay node, and cross-network node, and summarize them to form the complete original transmission information of the reliable data; When the network environment is secure and controllable, the MD5 value is used to quickly verify the file. When the network environment is not secure and the file security requirements are high, SHA-256 or a higher security verification code is used. S23, Cross-network distribution of monitoring information The collected link status information and reliable data transmission status are summarized and organized by the data transmission management center, and then interactively published through the one-way cross-network devices between the two networks.

4. The reliable data transmission method based on one-way cross-network transmission according to claim 3, characterized in that, Step S3 specifically includes: S31. Basic Information Release: The data transmission management center releases status information and default path information; S32. Sending Path Selection: The sending node executes different default path selection strategies based on the data type; S33. Data transmission execution: Each transmission node executes different data transmission strategies according to the data type.

5. A reliable data transmission method based on one-way cross-network transmission according to claim 4, characterized in that, Step S31 specifically includes: S311, Status monitoring information synchronization: The sending node obtains the status information of the sending nodes, relay nodes, and cross-network nodes that it can communicate with; S312, Default Path Synchronization: Each node synchronizes the default path for different data types. The basic information is a quadruple [data type, sender, predecessor node, successor node].

6. A reliable data transmission method based on one-way cross-network transmission according to claim 4, characterized in that, Step S32 specifically includes: S321. For time-sensitive data or composite data with time-sensitive requirements, perform full-path selection and optimal transmission. S322. For ordinary and reliable data, the default path is selected for transmission first. When the default path fails, the full path is selected for optimal transmission.

7. A reliable data transmission method based on one-way cross-network transmission according to claim 4, characterized in that, Step S33 specifically includes: S331. Transmit data according to the selected transmission path. The sending node records the transmission information to form a transmission list and sends it to the receiving node and the data transmission management center. S332, relay nodes, and cross-network front-end nodes forward data according to data priority, with higher priority data being forwarded first; S333, cross-network front-end nodes, and cross-network back-end nodes record data forwarding information to form a cross-network forwarding list, which is then sent to the data transmission management center; S334. The receiving node receives the sending list, records the received data information to form a receiving list, and sends it to the data transmission management center. For S335, time-sensitive, and ordinary data, data reception is complete. For reliable data or composite data with reliability requirements, after transmission is completed, check for data loss or damage.

8. A reliable data transmission method based on one-way cross-network transmission according to claim 7, characterized in that, Step S335 specifically includes: S3351. The receiving node needs to compare and check the information of the sent data list and the received data list to determine the data transmission loss or damage. S3352: The receiving node determines that all data has been received normally and sends a receiving list to the sender; if any data is lost or damaged, it initiates a retransmission request to the receiving node as needed. S3353: When the sending node receives a retransmission request, it retransmits as needed, repeating S331-S335; when the sending node receives the acceptance list sent by the receiving node, it completes the transmission loop.

9. A reliable data transmission method based on one-way cross-network transmission according to claim 8, characterized in that, Step S4 specifically includes: S41. Based on the device packet error rate obtained by the SNMP monitoring tool over a period of time and the cross-network transmission packet loss and bad packet rate obtained by comparing the cross-network forwarding list transmission and reception information reported by the cross-network front-end and back-end nodes, the transmission paths with and without cross-network devices are derived respectively. Average transmission success rate ; S42. Based on the transmission delay obtained by ICMP tools and the cross-network transmission duration obtained by comparing the cross-network forwarding list sent and received information reported by the cross-network front-end and back-end nodes, the transmission paths with and without cross-network devices are derived respectively. i Average response time ; S43. Based on the status information collected by the link status tool from the front-end nodes of the cross-network devices, obtain the current queuing status of the cross-network devices, and calculate the transmission path by combining the transmission capacity of the cross-network devices. Cross-network device busy rate : （1）； （2）； In equation (1), The estimated waiting time is given by n, where n is the total number of files queued for transmission in the cross-network front-end server, and j is the j-th file queued for transmission in the cross-network front-end server. For the size of the queued files, For unidirectional cross-network transmission equipment, the transmission bandwidth is provided. In equation (2), This is the waiting time threshold; S43. Calculate the transmission path by applying the linear weighting method to the above factors. Distance weight for: （3）； In equation (3), k1, k2, and k3 are weighting coefficients, which are used when the path does not contain cross-network devices. Set to 0; Distance weight Minimum transmission path As the optimal path, and set as the new default path.

Images