Custom instruction set programmable switching method based on SRv6 protocol in low earth orbit satellite network

Abstract

The invention discloses a programmable switching method for customizing an instruction set based on an SRv6 protocol in a low earth orbit satellite network, and relates to the technical field of aerospace systems. The method comprises the following steps: firstly, inputting a service data packet in a low-orbit satellite network; then judging whether the service data packet is an SRv6 data packet, if so, identifying a destination address according to a routing positioning field in the service data packet, querying an SID table, and obtaining corresponding fuction information; therefore, one of the processing flows of multi-protocol fusion processing, AES encryption processing and CRC verification processing is selected to be executed; querying an interface corresponding to the SID table for forwarding; and completing the programmable switching of the self-defined instruction set based on the SRv6 protocol in the low earth orbit satellite network. Otherwise, forwarding the IP data packet of the service data packet according to the IPv4 / v6 data packet processing logic. According to the invention, the problem of incompatibility of multiple protocols can be solved, high guarantee of information security is realized, and the information is verified to guarantee that errors or missing of the information caused by interference in the transmission process is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace systems, and in particular to a programmable switching method based on a custom instruction set of the SRv6 protocol in a low-orbit satellite network. Background Art

[0002] Currently, there is a problem of equipment rigidity in low-orbit satellite networks. The function of the equipment can only be changed by replacing the hardware, which may lead to problems such as increased network design costs and poor real-time performance of business scheduling and processing.

[0003] The Internet's initial design phase failed to consider the diverse development trends expected in future networks. Consequently, its protocol design failed to consider compatibility issues with heterogeneous network protocols. Consequently, directly applying the Internet Protocol to low-orbit satellite networks fails to meet the interconnection and interoperability requirements for nodes in different network architectures. Therefore, solving the problem of cross-domain communication between nodes has become an important research topic.

[0004] Currently, domestic scholars are primarily focusing their research on the prospects for civilian applications of software-defined networks and IPv6 networks. While SDN offers centralized control capabilities, distributed coordination of SDN controllers in wide-area networks remains a challenge. As the number of SDN controllers increases, network control performance decreases, making direct application of SDN architectures difficult. Currently, the most popular IPv6 network architecture is an upgraded version of the IPv4 network. By updating routing and IP address protocols, it significantly enhances the technical capabilities of the Internet. However, due to the greater complexity of the IPv6 protocol compared to IPv4, its promotion and application face numerous challenges. For example, IPv6 faces issues such as protocol incompatibility and the need for batch device updates, which limit its promotion and use in civilian network architectures.

[0005] Currently, domestic research focuses primarily on the development of mobile communication technologies, while research on cross-domain communication network architectures is relatively scarce. Huawei's proposed Network 5.0 architecture, considered a new paradigm for future internet network development, incorporates numerous new technologies, including temperature-sensitive networks, new transport, and new IP, aiming to address current internet network service transmission efficiency issues. However, the Network 5.0 architecture fails to fully consider the inherent characteristics of cross-domain capabilities, lacking in-depth research on supporting multi-system network convergence and the specialized requirements of combat networks. Consequently, it is unable to provide native cross-domain collaborative capabilities. Therefore, despite its impressive performance in civilian networks, the Network 5.0 architecture still has some distance to go before it can meet the demands of low-orbit satellite networks. Summary of the Invention

[0006] In light of this, the present invention proposes a programmable switching method based on a custom instruction set of the SRv6 protocol in low-orbit satellite networks. This method can resolve the issue of multiple protocol incompatibilities, achieve a high degree of information security, and verify information to ensure that it is not erroneous or missing due to interference during transmission.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A programmable switching method based on a custom instruction set of the SRv6 protocol in a low-orbit satellite network edits a service data packet in the SRv6 protocol format, fills in the routing location field in the Segment List field with information on all routing nodes that the service data packet passes through from the source node to the destination node, and fills in the function field in the Segment List field with the function code to be executed at the corresponding node. The function code includes multi-protocol fusion processing, AES encryption processing, and CRC check processing; the programmable switching method includes the following steps:

[0009] Step 1: Inputting a service data packet into the low-orbit satellite network;

[0010] Step 2: Determine whether the service data packet is an SRv6 data packet. If so, proceed to step 3. Otherwise, forward the service data packet as an IP data packet according to the IPv4 / v6 data packet processing logic.

[0011] Step 3: Identify the destination address based on the routing location field in the service data packet;

[0012] Step 4: Query the SID table to obtain the corresponding Function information; thereby selecting one of the three processing flows: multi-protocol fusion processing, AES encryption processing, and CRC check processing;

[0013] Step 5: Query the interface corresponding to the SID table for forwarding; complete the programmable switching based on the SRv6 protocol custom instruction set in the low-orbit satellite network.

[0014] Furthermore, the specific method of executing the multi-protocol fusion processing flow in step 4 is:

[0015] The multi-protocol fusion processing process requires the use of the following three table information: specifically including the satellite-to-ground label forwarding table, the satellite-to-ground label mapping table and the switch port forwarding table;

[0016] The satellite-to-ground label forwarding table includes a mapping relationship between satellite node number and switch outlet number;

[0017] The satellite-to-ground label mapping table includes a mapping relationship between IP address, satellite node number, and satellite port number;

[0018] The switch port forwarding table includes a mapping relationship between the switch outlet number and the feed channel IP address;

[0019] The multi-protocol fusion processing flow parses the data packet format of the ground core network and converts it into the on-board data format, that is, the transmission path from the ground network element to the feeding baseband. The ground network element sends the data to the switch. The switch first converts the content and format of the data field, and then searches and performs address conversion according to the satellite-to-ground label forwarding table, satellite-to-ground label mapping table and switch port forwarding table configured by the controller. First, the satellite-to-ground label mapping table is searched by the IPv6 address sent to the device to obtain the corresponding satellite number and port number. Then, the satellite number is used to search the satellite-to-ground label forwarding table to obtain the switch outlet number. Finally, the switch outlet number is used to search the switch port forwarding table to obtain the IPv6 address of the feeding channel to be sent. Finally, the feeding address is updated to the destination IPv6 address of the data packet. After the conversion is completed, the source IPv6 address of the data packet is the switch, and the destination IPv6 address is the feeding baseband. At this time, the data packet will be sent to the correct feeding baseband according to the specified routing forwarding strategy.

[0020] Uplink configuration includes:

[0021] Add a custom protocol header to distinguish between public and private protocols and carry satellite synchronization information;

[0022] Data shift: During uplink data packet processing, after adding the custom protocol header, the data field of the data packet is shifted as a whole.

[0023] CRC check: A series of four arithmetic operations combined with a for loop are used to calculate the redundant code, calculate the CRC of the data packet and send it together with the data packet;

[0024] Filling IP / UDP information: Based on the actual length of the converted data packet, the total length field in the IP / UDP header is updated to ensure that it accurately reflects the number of bytes in the entire IP / UDP data packet; at the same time, the checksum field is recalculated and filled to ensure that the data packet can be transmitted normally;

[0025] Downlink configuration includes:

[0026] CRC check: A series of four arithmetic operations combined with a for loop are used to calculate the redundant code, calculate the CRC of the data packet and send it together with the data packet;

[0027] Stripping custom protocol headers: stripping custom message headers from data packets to ensure that data can be parsed and forwarded according to standard protocol formats;

[0028] Data shift: During downlink data packet processing, after stripping the custom protocol header, the data field of the data packet is shifted as a whole.

[0029] Filling IP / UDP information: Based on the actual length of the converted data packet, the total length field in the IP / UDP header is updated to ensure that it accurately reflects the number of bytes in the entire IP / UDP data packet; at the same time, the checksum field is recalculated and filled to ensure that the data packet can be transmitted normally.

[0030] Furthermore, the specific method of executing the AES encryption process in step 4 is as follows:

[0031] Set the AES key length. The key length can be any one of 128 / 192 / 256 bits. The corresponding number of rounds is 10 / 12 / 14, respectively. Each round has four steps: byte substitution, row shift, column obfuscation, and round key addition. Before the first round, a round key addition is performed. In the last round, one less column obfuscation is performed, that is, one more round key addition and one less column obfuscation. After encryption, the ciphertext is obtained.

[0032] Furthermore, the specific method of executing the CRC check process in step 4 is as follows:

[0033] The initial value is selected according to different CRC modes, which is called the CRC register. Then the first 8-bit data is XORed with the lower eight bits of the CRC register, and the upper eight bits remain unchanged. The XORed value is used as the new CRC register. The next step is to detect whether the first bit of the register is 0 or 1. If it is 1, the register is shifted right by one bit and XORed with the binary reverse of the polynomial. If it is 0, the register is directly shifted right by one bit. This step is repeated continuously. After shifting right 8 times, a new CRC register is obtained. In this way, an 8-bit data is processed. The remaining data is processed in this way to obtain the final CRC register, which is the CRC check value.

[0034] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0035] 1. The present invention expands the multi-protocol fusion instruction set and adopts a streaming editing method to perform protocol conversion processing on the data packets in transmission, thereby solving the problem of incompatibility of multiple protocols.

[0036] 2. The present invention expands the information security instruction set and encrypts important information through encryption algorithms to ensure security, thereby achieving a high level of information security.

[0037] 3. The present invention extends the information verification instruction set and verifies the information through a verification algorithm to ensure that the information is not erroneous or missing due to interference during transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is an overall flow chart of a programmable switching method based on a custom instruction set of the SRv6 protocol in a low-orbit satellite network according to an embodiment of the present invention.

[0039] Figure 2 Schematic diagram of the SRv6 protocol format in an embodiment of the present invention.

[0040] Figure 3 This is a reference format diagram of the Segment list field in the SRv6 protocol format in an embodiment of the present invention.

[0041] Figure 4 Schematic diagram of protocol conversion rules in an embodiment of the present invention.

[0042] Figure 5 The figure is a schematic diagram of the protocol conversion uplink configuration in an embodiment of the present invention.

[0043] Figure 6 The figure is a schematic diagram of the protocol conversion downlink configuration in an embodiment of the present invention.

[0044] Figure 7 Schematic diagram of the AES encryption process in an embodiment of the present invention.

[0045] Figure 8 This is a flow chart of the CRC algorithm in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0047] A programmable switching method based on a custom instruction set of the SRv6 protocol in a low-orbit satellite network edits the service data packet in the SRv6 protocol format, fills in the routing location field in the Segment List field with information on all routing nodes that the service data packet passes through from the source node to the destination node, and fills in the function field in the Segment List field with the function code that needs to be executed at the corresponding node. The function code includes multi-protocol fusion processing, AES encryption processing, and CRC check processing; Figure 1 As shown, the programmable switching method includes the following steps:

[0048] Step 1: Inputting a service data packet into the low-orbit satellite network;

[0049] Step 2: Determine whether the service data packet is an SRv6 data packet. If so, proceed to step 3. Otherwise, forward the service data packet as an IP data packet according to the IPv4 / v6 data packet processing logic.

[0050] Step 3: Identify the destination address based on the routing location field in the service data packet;

[0051] Step 4: Query the SID table to obtain the corresponding Function information; thereby selecting one of the three processing flows: multi-protocol fusion processing, AES encryption processing, and CRC check processing;

[0052] Step 5: Query the interface corresponding to the SID table for forwarding; complete the programmable switching based on the SRv6 protocol custom instruction set in the low-orbit satellite network.

[0053] Specifically, such as Figure 2 、 Figure 3 As shown in the SRv6 protocol format diagram, the Segment List field is defined. This field allows you to enter information about all routing nodes that the service data packet passes through from the source node to the destination node, such as the source node IP address, first hop IP address, second hop IP address, etc., and the destination node IP address. The Function field also allows you to enter the function code to be executed at the corresponding node.

[0054] When a service packet is delivered to the corresponding node IP, the Function field indicates the function to be executed at that node IP. These functions are distinguished by different Function names. Using these different Function names, different function functions can be activated to process the data field of the service packet, thereby enabling SRv6 to flexibly schedule different functions. Considering that SRv6 already has some standard functions, these functions are referred to as instruction sets in the SRv6 standard. In addition to standard functions, this invention supports additional extended instructions to form a customized, extended instruction set, thereby enabling more flexible network processing capabilities.

[0055] Three practical application scenarios are given below.

[0056] (1) Implementation of multi-protocol fusion instruction set:

[0057] The innovation of custom protocol conversion functions in SRv6 networks lies in completely breaking down protocol barriers between networks. SRv6's programmable data plane enables lossless convergence of heterogeneous protocols and intelligent path optimization, thereby building an integrated, natively collaborative transmission system. Traditional protocol conversion relies on dedicated gateways, increasing end-to-end latency, limiting flexibility, and making it difficult to adapt to dynamic topologies. SRv6, by defining custom segments, enables access nodes to directly trigger protocol conversion logic during forwarding. When a packet carrying that SID enters the node, the parser extracts protocol metadata and maps it to an SRv6 extension header or dynamically reconstructs it into a standard IPv6 / SRH format. By atomically converting protocol fields bit by bit within a single hop, the protocol fields are mapped, eliminating the full packet parsing and reconstruction overhead of traditional gateways, reducing latency from milliseconds to microseconds. This design elevates satellite nodes from "transparent relays" to "protocol-agnostic intelligent service nodes," supporting seamless end-to-end service chain collaboration and providing highly reliable, low-latency, integrated transmission capabilities for global IoT, emergency response, and other scenarios.

[0058] The table entry information used by the multi-protocol fusion instruction set is as follows:

[0059] Table 1.1 Satellite-to-ground label forwarding table

[0060] Satellite node number exit Satellite 1 Switch outlet number …… …… Satellite N Switch outlet number

[0061] Table 1.2 Satellite-to-ground label mapping table

[0062]

[0063]

[0064] Table 1.3 Switch port forwarding table

[0065] exit Feed channel Switch outlet number Feed channel IP address …… ……

[0066] The protocol conversion function currently supported by the system is to parse the data packet format of the ground core network and convert it into the satellite data format. It refers to the transmission path from the ground network element to the feed baseband. The ground network element sends the data to this switch, and the switch first analyzes the content and format of the data field according to the Figure 4The conversion rules shown are then used to perform the conversion. The controller then searches and performs address conversion based on the satellite-to-ground label forwarding table, satellite-to-ground label mapping table, and switch port forwarding table configured on the switch. The satellite number and port number are first retrieved from the satellite-to-ground label mapping table using the IPv6 address sent to the device. The satellite number is then used to retrieve the switch outlet number. Finally, the switch outlet number is used to retrieve the switch port forwarding table to obtain the IPv6 address of the feed channel being sent. The retrieved feed address is then updated to the destination IPv6 address of the packet. In summary, after the conversion is complete, the source IPv6 address of the packet is the switch, and the destination IPv6 address is the feed baseband. At this point, the packet will be sent to the correct feed baseband according to the specified routing forwarding strategy.

[0067] For uplink configuration, Figure 5 As shown:

[0068] ●Add custom protocol header: In addition to the standard protocol fields, the protocol gateway needs to add additional custom protocol headers. The custom protocol header is a mark used to distinguish public protocols from private protocols. It carries satellite synchronization information and may contain key information required by users.

[0069] ●Data shift: During uplink data packet processing, after adding a custom protocol header, the data field of the data packet needs to be shifted as a whole to ensure the integrity of the data structure and the correctness of the protocol parsing. During this process, the data content itself does not change, only the format is adjusted.

[0070] CRC Check: This stage calculates the CRC (Cyclic Redundancy Check) of the data packet to ensure data integrity. The CRC uses a series of four arithmetic operations combined with a for loop to calculate the redundancy code and send it along with the packet. It's important to note that while the computational complexity of each iteration is relatively low, the number of check iterations required increases with packet length, causing the overall computational complexity to increase linearly with data length. Therefore, the associated latency of this process is not negligible.

[0071] Filling IP / UDP information: Update the total length field in the IP / UDP header based on the actual length of the converted packet to ensure it accurately reflects the number of bytes in the entire IP / UDP packet. Also, recalculate and fill in the checksum field to ensure the packet can be transmitted properly.

[0072] ●Configure antenna mapping IP: Restore the actual IP address based on the mapping information provided by the device communication module.

[0073] For downlink configuration, Figure 6 As shown:

[0074] CRC Check: This stage calculates the CRC (Cyclic Redundancy Check) of the data packet to ensure data integrity. The CRC uses a series of four arithmetic operations combined with a for loop to calculate the redundancy code and send it along with the packet. It's important to note that while the computational complexity of each iteration is relatively low, the number of check iterations required increases with packet length, causing the overall computational complexity to increase linearly with data length. Therefore, the associated latency of this process is not negligible.

[0075] ● Stripping custom protocol headers: Satellite downlink data packets contain custom message headers that are used to distinguish between public and private protocols and may carry key data such as satellite synchronization information. When processing downlink data, the custom message headers in the data packets need to be stripped to ensure that the data can be parsed and forwarded according to the standard protocol format.

[0076] ●Data shift: During downlink data packet processing, after stripping the custom protocol header, the data field of the data packet needs to be shifted as a whole to ensure the integrity of the data structure and the correctness of the protocol parsing. During this process, the data content itself does not change, only the format is adjusted.

[0077] Filling IP / UDP information: Update the total length field in the IP / UDP header based on the actual length of the converted packet to ensure it accurately reflects the number of bytes in the entire IP / UDP packet. Also, recalculate and fill in the checksum field to ensure the packet can be transmitted properly.

[0078] (2) Implementation plan for information security instruction set:

[0079] Integrating custom encryption functionality with forwarding logic in an SRv6 network can be achieved by defining a specific SRv6 Segment whose Function field explicitly indicates that the packet requires encryption. When a packet enters an SRv6-enabled programmable switch or node, the parser identifies the destination address and performs a table lookup based on the destination address. If the table lookup matches an encryption segment, the data plane executes the pre-defined encryption operations: first, the packet's payload (IPv6 or transport layer payload) is extracted, the AES encryption module in the code is invoked to encrypt the payload, the checksum is updated, and the packet is forwarded based on the next SID in the Segment Routing Header (SRH). This design leverages the network programmability of SRv6 to seamlessly embed encryption functionality into the forwarding pipeline, while also enabling flexible service chaining through explicit segment path control. Furthermore, DPDK acceleration ensures high-performance encryption throughput, ultimately achieving a balance between security and efficiency.

[0080] After the data packet enters the program, it first determines whether it is an SRv6 data packet. If it is an IPv4 / v6 data packet, it enters the IP data packet forwarding process. If it is an SRv6 data packet, it identifies the target address, queries the SID table through the address, and obtains the corresponding Function information. If the instruction is encrypted, it enters the AES encryption process. After processing is completed, it enters the SRv6 data packet forwarding process.

[0081] The information security instruction set can be used to encrypt and hide the contents of data packets containing important information during transmission to ensure security. The AES encryption algorithm is used in the information security instruction set to encrypt the data field of the data packet. The specific operation process of the AES encryption algorithm is as follows: Figure 7 As shown in the figure. In the AES algorithm, the block length is 128 bits, and the key length is optional, available in 128, 192, or 256 bits, corresponding to 10, 12, or 14 rounds, respectively. Taking the 128-bit key length used in this project as an example, there are 10 rounds in total. Each round consists of four steps: byte substitution, row shift, column obfuscation, and round key addition. Round key addition is performed before the first round, and column obfuscation is reduced in the final round, the tenth round. Overall, one more round key addition and one less column obfuscation are performed, resulting in the ciphertext after encryption.

[0082] The implementation flow chart of the information security instruction set is as follows: Figure 7As shown, first obtain the data of the data packet, use the preset key, and encrypt it through the AES algorithm to obtain the encrypted data field and combine it with the previous header to generate a new data packet. After the combination is successful, the data packet is forwarded through the port corresponding to the SID table.

[0083] (3) Implementation of information verification instruction set:

[0084] The core method for implementing a custom function in an SRv6 network to add a CRC check at the end of a packet and forward it requires tightly integrating SRv6 segment semantics with data plane processing logic. First, a specific SID is defined, which points to the node performing the check. The function portion identifies the CRC algorithm. When a packet arrives at a node configured with this SID, the parser recognizes the function code and triggers a pipeline action. It extracts a specified range of data (such as the transport layer payload or the entire packet), invokes the software's CRC calculation to generate a checksum, then appends the CRC field to the end of the packet and updates the payload length field in the IPv6 header. Finally, the packet is forwarded based on the next-hop SID in the SRH. Implementation requires addressing key issues such as dynamic length field correction, flexible definition of the check range (e.g., full-packet check skips IPv6 variable header fields), and reverse parsing verification at the receiving end. This design shifts data integrity protection from the application layer to the network layer, leveraging SRv6 programmability to achieve line-speed processing. It is suitable for scenarios with stringent transmission reliability requirements. It can also be freely combined with functional segments such as encryption and protocol conversion to build a secure service chaining system.

[0085] After the data packet enters the program, it first determines whether it is an SRv6 data packet. If it is an IPv4 / v6 data packet, it enters the IP data packet forwarding process. If it is an SRv6 data packet, it identifies the target address, queries the SID table through the address, and obtains the corresponding Function information. If the instruction is CRC, it enters the CRC check process. After the processing is completed, it enters the SRv6 data packet forwarding process.

[0086] The information verification instruction set can be used to verify the contents of the data packet during transmission to check whether there are any abnormalities such as missing data or data errors during transmission, so as to ensure the integrity and correctness of the data packet during transmission. The information verification instruction set uses the CRC algorithm to verify the data field of the entire data packet. The CRC verification algorithm can efficiently detect errors in the data packet and has a low false positive rate. The verification process of the CRC algorithm is as follows: Figure 8As shown. First, the initial value is selected according to different CRC modes, which is called the CRC register. Then, the first 8-bit data is XORed with the lower eight bits of the CRC register, while the upper eight bits remain unchanged. The XORed value is used as the new CRC register. The next step is to check whether the first bit of the register is 0 or 1. If it is 1, the register is shifted right by one bit and XORed with the binary reverse of the polynomial. If it is 0, the register is directly shifted right by one bit. This step is repeated continuously. After shifting right 8 times, a new CRC register is obtained. In this way, one 8-bit data is processed. The remaining data is processed in this way to obtain the final CRC register, which is also the CRC check value.

[0087] In summary, this paper leverages the extensibility of the SRv6 Function field to propose a custom instruction set approach to address the rigidity of low-orbit satellite network equipment. This system extends the system with three custom instruction sets: information security, multi-protocol fusion, and information verification. The implementation schemes for each of these custom instruction sets are presented, and functional testing is performed in a simulated environment using a network tester, demonstrating their feasibility and correctness.

[0088] Those skilled in the art will appreciate that the embodiments described are intended to help readers understand the principles of the present invention and should be understood that the scope of protection of the present invention is not limited to the embodiments described. It will be apparent to those skilled in the art that various modifications and variations are possible in the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A programmable switching method based on a custom instruction set of the SRv6 protocol in a low-orbit satellite network, characterized in that: Edit the service data packet in SRv6 protocol format, fill the routing location field in the Segment List field with information about all routing nodes that the service data packet passes through from the source node to the destination node, and fill the function code that needs to be executed at the corresponding node in the Function field in the Segment List field. The function code includes multi-protocol fusion processing, AES encryption processing, and CRC check processing; The programmable switching method comprises the following steps: Step 1: Inputting a service data packet into the low-orbit satellite network; Step 2: Determine whether the service data packet is an SRv6 data packet. If so, proceed to step 3. Otherwise, forward the service data packet as an IP data packet according to the IPv4 / v6 data packet processing logic. Step 3: Identify the destination address based on the routing location field in the service data packet; Step 4: Query the SID table to obtain the corresponding Function information; thereby selecting one of the three processing flows: multi-protocol fusion processing, AES encryption processing, and CRC check processing; Step 5: Query the interface corresponding to the SID table for forwarding; complete the programmable switching based on the SRv6 protocol custom instruction set in the low-orbit satellite network.

2. The method for programmable switching based on the SRv6 protocol custom instruction set in a low-orbit satellite network according to claim 1, characterized in that: The specific method of executing the multi-protocol fusion process in step 4 is as follows: The multi-protocol fusion processing process requires the use of the following three table information: specifically including the satellite-to-ground label forwarding table, the satellite-to-ground label mapping table and the switch port forwarding table; The satellite-to-ground label forwarding table includes a mapping relationship between satellite node number and switch outlet number; The satellite-to-ground label mapping table includes a mapping relationship between IP address, satellite node number, and satellite port number; The switch port forwarding table includes a mapping relationship between the switch outlet number and the feed channel IP address; The multi-protocol fusion processing flow parses the data packet format of the ground core network and converts it into the on-board data format, that is, the transmission path from the ground network element to the feeding baseband. The ground network element sends the data to the switch. The switch first converts the content and format of the data field, and then searches and performs address conversion according to the satellite-to-ground label forwarding table, satellite-to-ground label mapping table, and switch port forwarding table configured by the controller. First, the satellite-to-ground label mapping table is searched by the IPv6 address sent to the device to obtain the corresponding satellite number and port number. Then, the satellite number is used to search the satellite-to-ground label forwarding table to obtain the switch outlet number. Finally, the switch outlet number is used to search the switch port forwarding table to obtain the IPv6 address of the feeding channel to which it is sent. Finally, the feeding address is updated to the destination IPv6 address of the data packet. After the conversion is completed, the source IPv6 address of the data packet is the switch, and the destination IPv6 address is the feeding baseband. At this point, the data packet will be sent to the correct feeding baseband according to the specified routing forwarding strategy; Uplink configuration includes: Add a custom protocol header to distinguish between public and private protocols and carry satellite synchronization information; Data shift: During uplink data packet processing, after adding the custom protocol header, the data field of the data packet is shifted as a whole. CRC check: A series of four arithmetic operations combined with a for loop are used to calculate the redundant code, calculate the CRC of the data packet and send it together with the data packet; Filling IP / UDP information: Based on the actual length of the converted data packet, the total length field in the IP / UDP header is updated to ensure that it accurately reflects the number of bytes in the entire IP / UDP data packet; at the same time, the checksum field is recalculated and filled to ensure that the data packet can be transmitted normally; Downlink configuration includes: CRC check: A series of four arithmetic operations combined with a for loop are used to calculate the redundant code, calculate the CRC of the data packet and send it together with the data packet; Stripping custom protocol headers: stripping custom message headers from data packets to ensure that data can be parsed and forwarded according to standard protocol formats; Data shift: During downlink data packet processing, after stripping the custom protocol header, the data field of the data packet is shifted as a whole. Filling IP / UDP information: Based on the actual length of the converted data packet, the total length field in the IP / UDP header is updated to ensure that it accurately reflects the number of bytes in the entire IP / UDP data packet; at the same time, the checksum field is recalculated and filled to ensure that the data packet can be transmitted normally.

3. The programmable switching method based on the SRv6 protocol custom instruction set in the low-orbit satellite network according to claim 1 is characterized in that: The specific method of executing the AES encryption process in step 4 is as follows: Set the AES key length. The key length can be any one of 128 / 192 / 256 bits. The corresponding number of rounds is 10 / 12 / 14, respectively. Each round has four steps: byte substitution, row shift, column obfuscation, and round key addition. Before the first round, a round key addition is performed. In the last round, one less column obfuscation is performed, that is, one more round key addition and one less column obfuscation. After encryption, the ciphertext is obtained.

4. The method for programmable switching based on the SRv6 protocol custom instruction set in a low-orbit satellite network according to claim 1, characterized in that: The specific method of executing the CRC check process in step 4 is as follows: The initial value is selected according to different CRC modes, which is called the CRC register. Then the first 8-bit data is XORed with the lower eight bits of the CRC register, and the upper eight bits remain unchanged. The XORed value is used as the new CRC register. The next step is to detect whether the first bit of the register is 0 or 1. If it is 1, the register is shifted right by one bit and XORed with the binary reverse of the polynomial. If it is 0, the register is directly shifted right by one bit. This step is repeated continuously. After shifting right 8 times, a new CRC register is obtained. In this way, an 8-bit data is processed. The remaining data is processed in this way to obtain the final CRC register, which is the CRC check value.

Images