Communication method, storage medium and computer program product

Abstract

The invention discloses a communication method, a storage medium and a computer program product, and relates to the technical field of network communication, and the method comprises the steps: obtaining a data packet at a first communication node, and transmitting the data packet to a bridge node through a first communication link when a cross fault occurs in independent dual networks; the bridging node identifies, splits and re-encapsulates the data packet, generates a new data packet and sends the new data packet to the second communication node through the second communication link; the second communication node responds to the acquired data information, generates a responded data packet and sends the responded data packet to the bridge node through a second communication link; the bridge node identifies, splits and re-encapsulates the responded data packet, generates a new responded data packet, and sends the new responded data packet to the first communication node through the first communication link; and obtaining the responded data information. According to the invention, the normal communication of the network can be ensured when the cross fault occurs in the independent dual-network mode.

Description

Technical Field

[0001] This invention relates to the field of network communication technology, and in particular to a communication method, storage medium, and computer program product. Background Technology

[0002] Independent dual-network mode is a common high-availability network technology. It uses two independent IP networks for communication. In an independent dual-network environment, because the two links are independent and unrelated, a failure of either link does not affect communication. However, if a cross-link failure occurs at either end, normal communication between the two ends will be impossible. Specifically, if communication ends A and B communicate via link L1 and link L2 respectively, with A's L1 and B's L1 sharing the same link, and A's L2 and B's L2 sharing the same link, then a cross-link failure occurs. If A's L1 link fails but B's L1 link remains active, and B's L2 link fails but A's L2 link remains active, then a cross-link failure occurs in the A-B communication chain.

[0003] Therefore, ensuring normal network communication in the event of a cross-network failure in independent dual-network mode is a critical issue that urgently needs to be addressed. Summary of the Invention

[0004] This invention provides a communication method, storage medium, and computer program product that can ensure normal network communication when a cross-fault occurs in an independent dual-network mode.

[0005] This invention provides a communication method applied to an independent dual-network communication system. The independent dual-network communication system includes a first communication node, a bridging node, and a second communication node. A first communication link and a second communication link are configured between the first communication node and the second communication node. The first communication link is connected to the second communication link through the bridging node. The method includes: The bridging node receives and parses a first data packet from the first communication node through the first communication link; wherein, the first data packet includes a first auxiliary field, a first routing field, and original data, the first auxiliary field is used to indicate that the bridging node receives the original data sent by the first communication node through the first communication link, and the first routing field is used to characterize the route from the first communication node to the bridging node; The bridging node modifies the first auxiliary field to a second auxiliary field and modifies the first routing field to a second routing field; the second auxiliary field is used to instruct the bridging node to send the original data to the second communication node through the second communication link, and the second routing field is used to characterize the route from the bridging node to the second communication node; The bridging node generates a second data packet based on the second auxiliary field, the second routing field, and the original data, and sends the second data packet to the second communication node through the second communication link.

[0006] This invention provides a communication method applied to an independent dual-network communication system. The independent dual-network communication system includes a first communication node, a bridging node, and a second communication node. A first communication link and a second communication link are configured between the first communication node and the second communication node. The first communication link is connected to the second communication link through the bridging node. The method includes: The application layer of the first communication node generates the raw data to be sent to the second communication node and transmits the raw data to the kernel layer of the first communication node; If the kernel layer of the first communication node detects a cross-failure between the first communication link and the second communication link, it encapsulates an auxiliary field and a routing field on the outer layer of the original data, generates a data packet, and sends the data packet to the bridge node through the first communication link. The auxiliary field is used to instruct the bridge node to receive the original data sent by the first communication node through the first communication link, and the routing field is used to characterize the route from the first communication node to the bridge node.

[0007] Further, the step of encapsulating auxiliary fields and routing fields on the outer layer of the original data to generate a data packet includes: The network layer, transport layer, and data area used by the first communication node to communicate with the second communication node are taken as the original data; The data link layer Ethernet frame header is encapsulated as an auxiliary field on the outer layer of the original data. The original data is encapsulated in a network layer IP header that does not contain an Option field, and the Option field in the network layer IP header is used as a routing field to generate a data packet.

[0008] Furthermore, the Option area in the network layer IP header includes a 4-byte identifier, a 4-byte source link information, a 4-byte destination link information, and an 8-byte reserved space.

[0009] Furthermore, after the application layer of the first communication node generates the raw data to be sent to the second communication node and transmits the raw data to the kernel layer of the first communication node, it also includes: When the kernel layer of the first communication node detects that the first communication link and the second communication link have returned to normal, it stops encapsulating auxiliary fields and routing fields on the outer layer of the original data; The raw data is sent to the second communication node via the first communication link and the second communication link, respectively.

[0010] This invention provides a communication method applied to an independent dual-network communication system. The independent dual-network communication system includes a first communication node, a bridging node, and a second communication node. A first communication link and a second communication link are configured between the first communication node and the second communication node. The first communication link is connected to the second communication link through the bridging node. The method includes: The kernel layer of the second communication node receives data packets sent from the bridging node; wherein the data packets include auxiliary fields, routing fields, and raw data; The auxiliary fields of the data packet identify that the data packet was sent by the bridging node through the second communication link; The auxiliary fields and routing fields of the data packet are discarded, and the original data is passed to the application layer of the second communication node.

[0011] Further, after transmitting the original data to the application layer of the second communication node, the process includes: The second communication node responds to the original data and generates the original response data; The application layer of the second communication node transmits the raw data of the response to the kernel layer of the second communication node; The kernel layer of the second communication node encapsulates the auxiliary fields and routing fields of the response on the outer layer of the original response data to generate the response data packet; The second communication node sends the response data packet back to the bridge node via the second communication link.

[0012] This invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the communication method described above.

[0013] This invention provides a computer program product, which includes a computer program that, when executed by a processor, implements the communication method described above.

[0014] This invention provides a communication method, a storage medium, and a computer program product, which have the following advantages compared with the prior art: The data packet includes an auxiliary field, a routing field, and raw data. The bridging node receives and parses the first data packet from the first communication node via the first communication link. In the first data packet, the first auxiliary field instructs the bridging node to receive the raw data sent by the first communication node via the first communication link, and the first routing field characterizes the route from the first communication node to the bridging node. Next, the bridging node modifies the first auxiliary field to a second auxiliary field and modifies the first routing field to a second routing field. The second auxiliary field instructs the bridging node to send the raw data to the second communication node via the second communication link, and the second routing field characterizes the route from the bridging node to the second communication node. Finally, the bridging node generates a second data packet based on the second auxiliary field, the second routing field, and the raw data, and sends the second data packet to the second communication node via the second communication link. During this process, the information received by the second communication node only contains the raw data from the first communication node and does not contain the information of the bridging node. Therefore, the communication between the first and second communication nodes receives the raw data both before and after the addition of the bridging node, without any extra information from the bridging node. This ensures that even if a cross-connection failure occurs, the network can still maintain normal communication after connecting the first and second communication links using the bridging node. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an independent dual-network cross-connection fault provided in an embodiment of the present invention; Figure 2 This invention provides a data packet encapsulation format for AB communication via bridging terminal C, as provided in an embodiment of the invention. Figure 3 The OPTION area format in the auxiliary communication packet format provided in this embodiment of the invention; Figure 4 A schematic diagram of the cross-fault communication protection module provided in an embodiment of the present invention; Figure 5 A flowchart of a communication method provided in an embodiment of the present invention.

[0016] Attached label: 1- Client node A is connected to the L1 network, 2- Bridge node C is connected to the L1 network, 3- Bridge node C forwards traffic between the L1 and L2 networks, 4- Bridge node C is connected to the L2 network, 5- Server node B is connected to the L2 network. Detailed Implementation

[0017] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0018] like Figure 5 As shown, this embodiment of the invention provides a communication method applied to an independent dual-network communication system, which includes a first communication node, a bridging node, and a second communication node. It should be noted that the bridging node is not limited to a fixed node. In independent dual-network communication, each node participating in the independent dual network can act as a bridging node, rather than a separately designated bridging node. A first communication link and a second communication link are configured between the first and second communication nodes. The first communication link is connected to the second communication link through the bridging node. The method is implemented by the bridging node and includes the following steps: Step 1: The bridging node receives and parses the first data packet from the first communication node through the first communication link; wherein, the first data packet includes a first auxiliary field, a first routing field and raw data, the first auxiliary field is used to indicate that the bridging node receives the raw data sent by the first communication node through the first communication link, and the first routing field is used to characterize the route from the first communication node to the bridging node.

[0019] Step 2: The bridging node modifies the first auxiliary field to the second auxiliary field and modifies the first routing field to the second routing field; the second auxiliary field is used to indicate that the bridging node sends the original data to the second communication node through the second communication link, and the second routing field is used to characterize the route from the bridging node to the second communication node.

[0020] Step 3: The bridging node generates a second data packet based on the second auxiliary field, the second routing field, and the original data, and sends the second data packet to the second communication node through the second communication link.

[0021] This invention provides a communication method, implemented by a first communication node, comprising the following steps: Step 1: The application layer of the first communication node generates the raw data to be sent to the second communication node and transmits the raw data to the kernel layer of the first communication node.

[0022] Step 2: If the kernel layer of the first communication node detects a cross-failure between the first and second communication links, it encapsulates an auxiliary field and a routing field on the outer layer of the original data, generates a data packet, and sends the data packet to the bridge node through the first communication link. The auxiliary field is used to instruct the bridge node to receive the original data sent by the first communication node through the first communication link, and the routing field is used to characterize the route from the first communication node to the bridge node.

[0023] The process involves encapsulating auxiliary and routing fields on the outer layer of the original data to generate a data packet. Specifically, this includes: using the network layer, transport layer, and data area for communication between the first and second communication nodes as the original data; encapsulating the Ethernet frame header (data link layer) as an auxiliary field on the outer layer of the original data; and encapsulating the network layer IP header (excluding the Option field) and the Option field within the network layer IP header as routing fields on the outer layer of the original data to generate the data packet. The Option field in the network layer IP header includes a 4-byte identifier, 4 bytes of source link information, 4 bytes of destination link information, and 8 bytes of reserved space.

[0024] When the kernel layer of the first communication node detects that the first and second communication links have returned to normal, it stops encapsulating auxiliary fields and routing fields on the outer layer of the original data; and sends the original data to the second communication node through the first and second communication links respectively.

[0025] This invention provides a communication method implemented by a second communication node, comprising the following steps: Step 1: The kernel layer of the second communication node receives data packets sent from the bridging node; the data packets include auxiliary fields, routing fields, and raw data.

[0026] Step 2: Identify the data packet as being sent by the bridging node through the second communication link based on the auxiliary fields of the data packet.

[0027] Step 3: Discard the auxiliary fields and routing fields of the data packet and pass the original data to the application layer of the second communication node. The application layer of the second communication node responds to the original data, generating the original response data; the application layer of the second communication node passes the original response data to the kernel layer of the second communication node; the kernel layer of the second communication node encapsulates the auxiliary fields and routing fields of the response outside the original response data, generating the response data packet.

[0028] 1. The concept of this invention is as follows: In a dual-network topology, the two links are independent of each other. Data transmission on link one will not occur on link two. If a crossover failure occurs, communication is impossible on the link. This invention solves the communication interruption problem caused by crossover failures. Specifically, it describes how, with the assistance of a third node C (the bridging end, also referred to as the bridging node in this invention), communication between node A (i.e., the client, also referred to as the first communication node) and node C is via the L1 link (also referred to as the first communication link in this invention). Communication between node C and node B (i.e., the server, also referred to as the second communication node in this invention) is via the L2 link (also referred to as the second communication link in this invention). Data is transferred from the L1 link to the L2 link in node C. Conversely, data from node B to node C is via the L2 link, and data is transferred from the L2 link to the L1 link in node C, and then through the L1 link from node C to node A, thus completing the data transmission. Figure 1 As shown.

[0029] 2. The specific operation process of this invention is as follows: After node A discovers a communication failure with node B (fault identification occurs within the Linux kernel, unaware of the underlying communication failure at the upper-layer application level), it activates auxiliary communication via a third node C. First, A prepares the data to be sent to B according to... Figure 2 The data packet is encapsulated in the format shown and sent to C via the L2 link. C receives the data, identifies and decapsulates it, re-encapsulates the packet, and sends the new packet to B via the L1 link. B receives the packet, identifies and decapsulates it, and passes the normal data information to the Linux kernel network protocol stack. The information processed by the network protocol stack in B does not show that it originated from C; it only shows that the data came from A, and the network connection information also displays the connection established with A. After receiving the information, B generates response data, and similarly follows... Figure 2 The format repackages the data packet and sends it to C via the L1 link. C identifies the packet, unpacks it, repackages it, and sends it to A via the L2 link. A receives the packet, identifies and decrypts it, and then sends it to the Linux kernel network protocol stack. The network link that A sees is with B, not with C, thus enabling the two ends of the communication to continue communicating when a crossover failure occurs.

[0030] Before a crossover failure occurs, communication between A and B is normal. During the failure, communication automatically switches to auxiliary C. After the failure is recovered, it automatically switches back to direct communication between A and B. If it is TCP communication, the TCP connection session information is not terminated. The TCP seq / ack mechanism can maintain continuity and consistency in both the direct A and B connection and the ACB auxiliary mode, and is transparent to the upper layer application and is unaware of the failure. The above method ensures the continuity of communication.

[0031] like Figure 2 As shown, in the packet encapsulation format, K1 is the link layer header area, specifically containing the link layer header information for normal communication between AC, CB, BC, and CA. K2 is the network layer header area, specifically containing the network layer header information for normal communication between AC, CB, BC, and CA; this area does not include the network OPTION area. K3 contains the option area information of the K2 header, which is used to identify communication via C-assisted communication. Areas K4-K6 represent the network layer, transport layer, and data areas for normal A / B communication. These three areas ensure session consistency when switching between direct communication and assisted communication between A and B.

[0032] like Figure 3 The diagram shows the OPTION area format in the auxiliary communication packet format, which includes a 4-byte identification code, a 4-byte source link information, a 4-byte destination link information, and 8 bytes of reserved space.

[0033] like Figure 4 As shown, the cross-failure communication assurance module resides in the kernel layer, which includes the Linux kernel network protocol stack, the cross-failure communication assurance module, and the network driver. The cross-failure communication assurance module includes path management, packet identification and decomposition, and identification and assistance in packet encapsulation.

[0034] 3. The key points of this invention are: (1) a communication method implemented in the Linux kernel during cross-failures, which is transparent and imperceptible to the application. (2) a Linux kernel implementation module. (3) an innovative packet format is proposed. (4) compatibility and seamless switching of the seq / ack mechanism for TCP (Transmission Control Protocol) sessions are provided.

[0035] 4. This invention solves the problem of communication interruption caused by cross-connection failure in independent dual networks. Its advantages can be summarized as follows: (1) Implemented in the Linux kernel, it is transparent and unnoticed by upper-layer applications. It has good compatibility with the POSIX (Portable Operating System Interface) API and applications, and upper-layer applications do not need to make any modifications.

[0036] (2) TCP sessions are not interrupted due to cross-connect failures, and TCP's seq / ack mechanism can switch seamlessly.

[0037] (3) When a cross fault occurs, the TCP session and UDP related network information seen by the two ends of the communication node cannot detect the intermediate auxiliary node, and the existing network-related tools have good compatibility.

[0038] This invention provides a communication system, including: a first communication node, a second communication node, and a bridging node.

[0039] A bridging node is used to implement a communication method.

[0040] The first communication node is used to implement a communication method.

[0041] The second communication node is used to implement a communication method.

[0042] This invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of a communication method.

[0043] This invention provides a computer program product, which includes a computer program and, when executed by a processor, implements the steps of a communication method.

[0044] A specific example is as follows: This embodiment discloses a communication method, the specific steps of which are as follows: S1. The Linux kernel of the first communication node continuously monitors the network link between the first and second communication nodes. When a cross-connection failure occurs in the independent dual network, the first communication node acquires the first data packet. In the first data packet, the Ethernet frame header of the data link layer contains information for communication between the first communication node and the bridging node; the IP header of the network layer (excluding the Option field) contains information for communication between the first communication node and the bridging node; the Option field in the IP header contains information for identifying the need for auxiliary communication using the bridging node; the network layer of the IP protocol contains information for communication between the first and second communication nodes; the transport layer of the IP protocol contains information for communication between the first and second communication nodes; and the data area of ​​the IP protocol contains information for communication between the first and second communication nodes.

[0045] S2. The first data packet is sent to the second communication node via the first communication link through the first communication node.

[0046] S3. Based on the Option field in the network layer IP header of the first data packet received from the second communication link, the first data packet is identified as a data packet requiring auxiliary communication via a bridging node. The first data packet is disassembled, and the disassembled result is re-encapsulated to obtain the second data packet. In the second data packet, the data link layer Ethernet frame header contains information for communication between the bridging node and the second communication node; the network layer IP header (without an Option field) contains information for communication between the bridging node and the second communication node; the Option field in the network layer IP header contains information for identifying the need for auxiliary communication via a bridging node; the network layer of the IP protocol contains information for communication between the first and second communication nodes; the transport layer of the IP protocol contains information for communication between the first and second communication nodes; and the data area of ​​the IP protocol contains information for communication between the first and second communication nodes.

[0047] S4. The second data packet is sent to the second communication node via the second communication link through the bridging node.

[0048] S5. The second communication node disassembles the second data packet, obtains the network layer, transport layer and data area of ​​the IP protocol of the second data packet, and generates the application layer data information that needs to be transmitted to the second communication node.

[0049] S6. When the second communication node responds, it generates a third data packet. In the third data packet, the Ethernet frame header at the data link layer contains information for communication between the second communication node and the bridging node; the IP header at the network layer (excluding the Option field) contains information for communication between the second communication node and the bridging node; the Option field in the IP header contains information for identifying the need for auxiliary communication using the bridging node; the network layer of the IP protocol contains information for communication between the second communication node and the first communication node; the transport layer of the IP protocol contains information for communication between the second communication node and the first communication node; and the data area of ​​the IP protocol contains information for communication between the second communication node and the first communication node.

[0050] S7. The third data packet is sent to the bridge node via the second communication link through the second communication node.

[0051] S8. Based on the Option field in the network layer IP header of the third data packet received by the bridging node, the third data packet is identified as a data packet requiring auxiliary communication through the bridging node. The third data packet is disassembled, and the disassembled result is re-encapsulated to obtain the fourth data packet. In the fourth data packet, the data link layer Ethernet frame header contains information for communication between the bridging node and the first communication node; the network layer IP header (without an Option field) contains information for communication between the bridging node and the first communication node; the Option field in the network layer IP header contains information for identifying the need for auxiliary communication using the bridging node; the network layer of the IP protocol contains information for communication between the second communication node and the first communication node; the transport layer of the IP protocol contains information for communication between the second communication node and the first communication node; and the data area of ​​the IP protocol contains information for communication between the second communication node and the first communication node.

[0052] S9. The fourth data packet is sent to the first communication node via the first communication link through the bridging node.

[0053] S10. The first communication node disassembles the fourth data packet, obtains the network layer, transport layer and data area of ​​the IP protocol of the fourth data packet, and generates application layer data information that needs to be transmitted to the first communication node.

[0054] S11. When the Linux kernel of the first communication node detects that the first communication node and the second communication node can communicate directly, it determines that the independent dual network has returned to normal; it stops using the bridging node for auxiliary communication and sends data packets directly from the first communication node to the second communication node through the Linux kernel.

[0055] During this process, neither the information received by the second communication node nor the response information obtained by the first communication node contains information about the bridging node. It only contains the network layer, transport layer, and data area of ​​the IP protocol used for communication between the first and second communication nodes. Therefore, the information transmitted between the first and second communication nodes remains consistent with the information transmitted before the fault occurred, without any redundant bridging node information, thus ensuring normal network communication. Once a crossover fault occurs, the upper-layer applications of both the first and second communication nodes cannot perceive the change in communication method through the received information, and no modifications are required in the upper-layer applications when switching communication methods, resulting in good compatibility.

[0056] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A communication method, characterized in that, An independent dual-network communication system is applied, the independent dual-network communication system including a first communication node, a bridging node, and a second communication node, wherein a first communication link and a second communication link are configured between the first communication node and the second communication node, and the first communication link is connected to the second communication link through the bridging node; the method includes: The bridging node receives and parses a first data packet from the first communication node through the first communication link; wherein, the first data packet includes a first auxiliary field, a first routing field, and original data, the first auxiliary field is used to indicate that the bridging node receives the original data sent by the first communication node through the first communication link, and the first routing field is used to characterize the route from the first communication node to the bridging node; The bridging node modifies the first auxiliary field to a second auxiliary field and modifies the first routing field to a second routing field; the second auxiliary field is used to instruct the bridging node to send the original data to the second communication node through the second communication link, and the second routing field is used to characterize the route from the bridging node to the second communication node; The bridging node generates a second data packet based on the second auxiliary field, the second routing field, and the original data, and sends the second data packet to the second communication node through the second communication link.

2. A communication method, characterized in that, An independent dual-network communication system is applied, the independent dual-network communication system including a first communication node, a bridging node, and a second communication node, wherein a first communication link and a second communication link are configured between the first communication node and the second communication node, and the first communication link is connected to the second communication link through the bridging node; the method includes: The application layer of the first communication node generates the raw data to be sent to the second communication node and transmits the raw data to the kernel layer of the first communication node; If the kernel layer of the first communication node detects a cross-failure between the first communication link and the second communication link, it encapsulates an auxiliary field and a routing field on the outer layer of the original data, generates a data packet, and sends the data packet to the bridge node through the first communication link. The auxiliary field is used to instruct the bridge node to receive the original data sent by the first communication node through the first communication link, and the routing field is used to characterize the route from the first communication node to the bridge node.

3. The communication method as described in claim 2, characterized in that, The step of encapsulating auxiliary fields and routing fields on the outer layer of the original data to generate a data packet includes: The network layer, transport layer, and data area used by the first communication node to communicate with the second communication node are taken as the original data; The data link layer Ethernet frame header is encapsulated as an auxiliary field on the outer layer of the original data. The original data is encapsulated in a network layer IP header that does not contain an Option field, and the Option field in the network layer IP header is used as a routing field to generate a data packet.

4. The communication method as described in claim 3, characterized in that, The Option field in the network layer IP header includes a 4-byte identifier, a 4-byte source link information, a 4-byte destination link information, and 8 bytes of reserved space.

5. A communication method as described in claim 2, characterized in that, After the application layer of the first communication node generates the raw data to be sent to the second communication node and transmits the raw data to the kernel layer of the first communication node, the process further includes: When the kernel layer of the first communication node detects that the first communication link and the second communication link have returned to normal, it stops encapsulating auxiliary fields and routing fields on the outer layer of the original data; The raw data is sent to the second communication node via the first communication link and the second communication link, respectively.

6. A communication method, characterized in that, An independent dual-network communication system is applied, the independent dual-network communication system including a first communication node, a bridging node, and a second communication node, wherein a first communication link and a second communication link are configured between the first communication node and the second communication node, and the first communication link is connected to the second communication link through the bridging node; the method includes: The kernel layer of the second communication node receives data packets sent from the bridging node; wherein the data packets include auxiliary fields, routing fields, and raw data; The auxiliary fields of the data packet identify that the data packet was sent by the bridging node through the second communication link; The auxiliary fields and routing fields of the data packet are discarded, and the original data is passed to the application layer of the second communication node.

7. The communication method as described in claim 6, characterized in that, After transmitting the original data to the application layer of the second communication node, the process includes: The second communication node responds to the original data and generates the original response data; The application layer of the second communication node transmits the raw data of the response to the kernel layer of the second communication node; The kernel layer of the second communication node encapsulates the auxiliary fields and routing fields of the response on the outer layer of the original response data to generate the response data packet; The second communication node sends the response data packet back to the bridge node via the second communication link.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a communication method as described in any one of claims 1 to 7.

9. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements a communication method as described in any one of claims 1 to 7.

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