Network switch and network architecture for supporting heterogeneous network coupling and backup

Abstract

To provide a primary network switch, a backup network switch, and a network architecture.SOLUTION: A network system includes a primary network switch 22 that is configured in a main network operating with a redundancy protocol A, is used for coupling a sub-network operating with a redundancy protocol B, and executes a backup method. The backup method includes: sending a first control packet through at least one first connection port; receiving an ACK packet of the first control packet; switching a state of a second connection port; sending a second control packet through the at least one first connection port according to the redundancy protocol A to update a medium access control address table of the main network; and sending a third control packet through the second connection port according to the redundancy protocol B to update a medium access control address table of the sub-network.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus and a network architecture for network coupling and backup, and more particularly to a network switch and a network architecture for coupling and backup of heterogeneous networks. [Background technology]

[0002] With the ever-increasing demand for production capacity and cost in the industrial world, it has become a trend to connect production equipment to a network. The connection through a network can realize the collection and analysis of data across multiple devices, which can improve the speed, flexibility and efficiency of the process, reduce costs, and provide high-quality products. However, in a traditional industrial environment, multiple independent local area networks (LANs) exist simultaneously, which often makes integration and management difficult. In such cases, the prior art has proposed a network coupling technology that can connect multiple local area networks to each other and realize the sharing or integration of data and functions between different local area networks. Such a technology can solve the problem of intercommunication between different local networks and improve the efficiency and scalability of the system.

[0003] Generally, the architecture of an industrial control network may require multiple different sub-networks to access a main network (backbone network). In addition, the industrial control network often implements redundancy protocols to ensure the stability and reliability of the network, among which the sub-networks often implement redundancy protocols such as Rapid Spanning Tree Protocol (RSTP), Media Redundancy Protocol (MRP), etc., and the main network often implements High-availability Seamless Redundancy (HSR) or a private redundancy protocol customized by a switch manufacturer. However, when performing network merging, the main network and the sub-networks connected thereto generally need to use the same redundancy protocol to operate, so that the expansion of the network architecture becomes difficult when having multiple different redundancy protocols.

[0004] The prior art has proposed a technology for connecting heterogeneous networks, but there are many limitations on the connection method and device for network connection, for example, the main path and backup path of a subnetwork need to be connected to adjacent network nodes of the main network, and the network node for connection needs to simultaneously execute two different redundancy protocols of the main network and the subnetwork, or the main network needs to forward control packets of the redundancy protocol required for the subnetwork, in which case it is difficult to maintain the performance of the network nodes and the main network, and the problem becomes even more serious when a large number of subnetworks are connected. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Taiwan Patent No. I612783 [Patent Document 2] US Patent No. 9191273 [Non-patent literature]

[0006] [Non-Patent Document 1] User Manual, Redundancy Configuration Industrial ETHERNET Switch RS20, RSB20, 2010 / 07, P. 28-31, 68-71, Hirschmann Automation and Control GmbH, Neckartenzlingen, Germany. [Non-Patent Document 2] What options do you have for connecting an (R)STP segment to a ring structure and how can you reduce the ring reconfiguration time through the EPLC procedure?, 2018 / 04 / 25. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide a method and apparatus for network coupling of heterogeneous networks, in which a main network and a sub-network each operate according to different redundancy protocols when coupling the networks, thereby realizing a redundancy mechanism and improving performance. [Means for solving the problem]

[0008] An embodiment of the present invention provides a main network switch configured in a main network operating with a first redundancy protocol and used to couple a sub-network operating with a second redundancy protocol, the main network switch including at least one first connection port connected to the main network, a second connection port connected to the sub-network, a processing unit for executing program code, and a storage unit connected to the processing unit and storing program code for instructing the processing unit to execute a backup method for network coupling, the backup method including: transmitting a first control packet through the at least one first connection port; receiving an ACK packet of the first control packet when the first control packet is transmitted; switching a state of the second connection port when the ACK packet of the first control packet is received, transmitting a second control packet through the at least one first connection port according to the first redundancy protocol to update a media access control address table (MAC address table) of the main network, and transmitting a third control packet through the second connection port according to the second redundancy protocol to update the media access control address table of the sub-network.

[0009] An embodiment of the present invention further provides a backup network switch configured in a main network operating with a first redundancy protocol and used to couple a sub-network operating with a second redundancy protocol, the backup network switch including at least one first connection port connected to the main network, a second connection port connected to the sub-network, a processing unit for executing program code, and a memory unit connected to the processing unit and storing program code for instructing the processing unit to execute a backup method for network coupling, the backup method including the steps of switching a state of the second connection port, and transmitting a first control packet according to the first redundancy protocol via the at least one first connection port to update a media access control address table (MAC address table) of the main network, and transmitting a second control packet according to the second redundancy protocol via the second connection port to update the media access control address table of the sub-network.

[0010] An embodiment of the present invention is a network architecture for network coupling, comprising: a sub-network operating according to a first redundancy protocol; a main network operating according to a second redundancy protocol; a main network switch provided in the main network, connected to the main network via at least one first connection port and connected to the sub-network via a second connection port; and a backup network switch provided in the main network, connected to the main network via at least one third connection port and connected to the sub-network via a fourth connection port. The main network switch and the backup network switch execute a backup method for network coupling, the backup method including: the main network switch transmitting a first control packet via the at least one first connection port; when the first control packet is received, the backup network switch transmitting an ACK packet for the first control packet to switch a link; and transmitting a second control packet according to the second redundancy protocol via the at least one third connection port to update a media access control address table (MAC address table) of the main network. and sending a third control packet via the fourth connection port according to the first redundancy protocol to update a media access control address table of the sub-network, and, upon receiving the ACK packet for the first control packet, the main network switch switches links and sends a fourth control packet via the at least one first connection port according to the second redundancy protocol to update a media access control address table of the main network, and sends a fifth control packet via the second connection port according to the first redundancy protocol to update a media access control address table of the sub-network. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a network system. [Diagram 2] 1 is a partial schematic diagram of a network system according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic diagram of a polling process of a network connection backup method according to an embodiment of the present invention; [Figure 4] 2 is a schematic diagram of an aspect of a polling process performed by a network system in accordance with an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of a link validation process of a network connection backup method according to an embodiment of the present invention; [Figure 6] 4 is a schematic diagram of an aspect of a link activation process performed by a standby network switch in accordance with an embodiment of the present invention. [Figure 7] 4 is a schematic diagram of an aspect of a link activation process performed by a main network switch in accordance with an embodiment of the present invention. [Figure 8] 4 is a schematic diagram of a polling process performed by a standby network switch according to an embodiment of the present invention; [Figure 9] 4 is a schematic diagram of a polling process performed by a main network switch according to an embodiment of the present invention. [Figure 10] FIG. 2 is a schematic diagram of a link switching process of a network connection backup method according to an embodiment of the present invention; [Figure 11] 2 is a schematic diagram of an aspect of a link switching process performed by a network system in accordance with an embodiment of the present invention. [Figure 12] 2 is a schematic diagram of an aspect of a link switching process performed by a network system in accordance with an embodiment of the present invention. [Figure 13A] 13A and 13B are schematic diagrams of another aspect of a link switching process performed by a network system according to an embodiment of the present invention. [Figure 13B] 13A and 13B are schematic diagrams of another aspect of a link switching process performed by a network system according to an embodiment of the present invention. [Figure 14]FIG. 4 is a schematic diagram of another aspect of a link switching process performed by a network system according to an embodiment of the present invention. [Figure 15] FIG. 2 is a schematic diagram of a link switching process performed by a main network switch according to an embodiment of the present invention. [Figure 16] FIG. 2 is a schematic diagram of a link switching process performed by a standby network switch according to an embodiment of the present invention. [Figure 17] FIG. 2 is a schematic diagram of a chain network connection according to an embodiment of the present invention. [Figure 18] FIG. 2 is a schematic diagram of implementing a network connection backup method when connecting chained networks according to an embodiment of the present invention; [Figure 19] 1 is a schematic diagram of a network device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the specification and the following claims, certain terms are used to refer to certain elements. Those skilled in the art will understand that hardware manufacturers may refer to the same components by different nouns. In this specification and the following claims, the criteria for distinguishing elements are not differences in name, but differences in the functions of the elements. The term "including" referred to throughout this specification and the following claims is an open-ended term and should be interpreted as "including, but not limited to." In addition, the term "connected" includes direct and indirect electrical connection means. Thus, in the specification, a first device connected to a second device means that the first device may be directly electrically connected to the second device, or may be indirectly electrically connected to the second device through other devices or connection means.

[0013] FIG. 1 is a schematic diagram of a network system 1. As shown in FIG. 1, in the network system 1, one main network 10 connects a plurality of sub-networks 12_1-12_3. Here, the main network 10 operates according to a redundancy protocol A, and the sub-networks 12_1-12_3 operate according to redundancy protocols B-D, respectively. Specifically, the main network 10 is connected to the sub-networks 12_1-12_3 via a plurality of main links via a plurality of main network switches 14_1-14_3. At the same time, the main network 10 is connected to the sub-networks 12_1-12_3 via a plurality of spare network switches 16_1-16_3 via a plurality of spare links. Here, the plurality of spare network switches 16_1-16_3 and their spare links are in a standby state as backups for the plurality of main network switches 14_1-14_3 and their main links. As can be seen from FIG. 1, the network system 1 may be connected to a plurality of networks using different redundancy protocols. In the conventional technology, the switches for connecting the sub-networks need to simultaneously execute two different redundancy protocols. For example, the network switches 14_1 and 16_1 need to simultaneously execute redundancy protocols A and B, the network switches 14_2 and 16_2 need to simultaneously execute redundancy protocols A and C, and the network switches 14_3 and 16_3 need to simultaneously execute redundancy protocols A and D. This operation method increases the efficient burden on the network switches. On the other hand, in the conventional technology, the entire main network 10 is regarded as a single path, and it is possible to transfer control packets related to the redundancy protocols of the sub-networks 12_1 to 12_3 in the main network 10. In this case, as the number of connected sub-networks increases, the amount of control packets on the main network 10 also increases, affecting performance. Furthermore, in the conventional technology, it may not be possible to connect networks compatible with three or more redundancy protocols simultaneously.

[0014] Therefore, the present invention proposes a network coupling architecture and a backup method for network switches therein, which improves the shortcomings of the prior art. Here, the main network switch, the backup network switch and the links connecting to the sub-networks can be regarded as a coupling network, which serves as a communication bridge between the main network and the sub-networks. When the network switch performs a network backup such as link switching, it can notify the main network and the sub-networks of information on new paths according to the redundancy protocol for the main network and the sub-network to operate. Thus, the main network and the sub-networks can connect to each other and communicate with each other even when they are operating according to different redundancy protocols, and can provide stable performance without interfering with each other.

[0015] Fig. 2 is a partial schematic diagram of the network system 1 of Fig. 1. Specifically, Fig. 2 shows a connection form between the main network 10, the sub-network 20, the main network switch 22, and the spare network switch 24 according to an embodiment of the present invention. Here, the sub-network 20 indicates one of the sub-networks 12_1 to 12_3 in the network system 1 of Fig. 1, the main network switch 22 indicates a main network switch corresponding to the sub-network 20 in the main network switches 14_1 to 14_3, and the spare network switch 24 indicates a spare network switch corresponding to the sub-network 20 in the spare network switches 16_1 to 16_3. As shown in Fig. 2, the main network switch 22 is configured in the main network 10, and is connected to the main network 10 via the connection ports 222 and 224 through the links L3 and L4, and is connected to the sub-network 20 via the connection port 220 through the link L1 to perform data transfer. Meanwhile, the spare network switch 24 is configured in the main network 10, connected to the main network 10 via the links L5 and L6 through the connection ports 242 and 244, and connected to the subnetwork 20 via the link L2 through the connection port 240, and stands by as a backup for the main network switch 22. Note that the main network 10 is shown as a ring network in FIG. 2, but is not limited thereto, and the main network 10 may have various types of network topologies and is suitable for various redundancy protocols. Thus, the main network switch 22 and the spare network switch 24 are shown as being connected to the main network 10 via two connection ports, but are not limited thereto, and may be connected to the main network with different numbers of connection ports and links according to different network topologies. Also, in FIG. 2, the main network switch 22 and the spare network switch 24 are shown as being adjacent to each other, but are not limited thereto.The main network switch 22 and the backup network switch 24 may be adjacent (links L4, L5 are the same link) or may be connected via other network devices (not shown in FIG. 2) on the main network 10 (links L4, L5 are different links).

[0016] In the embodiment of FIG. 2, the network system 1 can be considered to be composed of three networks N1 to N3 for operating a backup mechanism. The network N1 is a main network 10, includes a main network switch 22 and a backup network switch 24, and operates according to a redundancy protocol A. If any device or link fails or becomes invalid, a backup may be performed according to the operation of the redundancy protocol A. The network N2 is a sub-network 20, includes network switches 26 and 28, and operates according to a redundancy protocol B. If any device or link fails or becomes invalid, a backup may be performed according to the operation of the redundancy protocol B. The networks N1 and N2 operate according to different redundancy protocols and do not affect each other. Meanwhile, the network N3 includes the main network switch 22, the backup network switch 24, the network switches 26, 28, and the links L1, L2, etc., that is, the above-mentioned coupling network, and when any device or link fails or becomes invalid, the links L1 and L2 are switched, and the operation of the different redundancy protocols of the main network 10 and the sub-network 20 is not affected. Specifically, when performing link switching in the network N3, the main network switch 22 and the backup network switch 24 may send a notification of a topology update to the main network 10 according to the redundancy protocol A via the connection ports 222, 224 and the connection ports 242, 244, respectively. At the same time, the main network switch 22 and the backup network switch 24 may send a notification of a topology update to the sub-network 20 according to the redundancy protocol B via the connection port 220 and the connection port 240, respectively. In this way, the network coupling can be prevented from being restricted by different redundancy protocols.

[0017] One embodiment of the backup method for network coupling in the network system 1 may be summarized as a polling process 30, as shown in Figure 3. The polling process 30 includes the following steps.

[0018] Step 300: The process begins.

[0019] Step 302: The standby network switch 24 periodically transmits a polling packet P1.

[0020] Step 304: The main network switch 22 judges whether the time during which the first polling packet P1 has not been received has reached a predetermined time. If YES, execute step 306; if not, execute step 308.

[0021] Step 306: The primary network switch 22 executes a link activation process.

[0022] Step 308: When the polling packet P1 is received, the main network switch 22 returns an ACK packet P1_ACK.

[0023] Step 310: The standby network switch 24 judges whether the number of times that the ACK packet P1_ACK has not been received reaches a predetermined number. If YES, execute step 312; if not, execute step 314.

[0024] Step 312: The standby network switch 24 performs a link activation process.

[0025] Step 314: End the process.

[0026] FIG. 4 is a schematic diagram of an aspect of a polling process 30 executed by the network system 1 according to an embodiment of the present invention. As shown in FIG. 4, the polling process 30 causes the standby network switch 24 to periodically transmit a polling packet P1 in the primary network 10 via the connection ports 242, 244 (step 302), and to determine the state of the primary network switch 22 based on whether the primary network switch returns a packet P1_ACK (step 310). When the primary network switch 22 receives the first control packet P1, the standby network switch 22 transmits an ACK packet P1_ACK in the primary network 10 via the connection ports 222, 224 (step 308). When the standby network switch 24 periodically transmits the polling packet P1 and does not receive the ACK packet P1_ACK a predetermined number of times, the standby network switch 24 may determine that the primary network switch 22 has become disabled (e.g., power outage or failure). Therefore, the standby network switch 24 needs to perform a link activation process to activate the link L2 to communicate with the sub-network 20 (step 312). Another situation of not receiving the ACK packet P1_ACK may be caused by all links (L3, L4) between the main network switch 22 and the main network 10 being disabled at the same time, and the standby network switch 24 similarly needs to perform a link enabling process to enable the link L2 to communicate with the sub-network 20 (step 312). Also, if all links (L5, L6) of the standby network switch 24 connected to the main network 10 are disabled at the same time, the standby network switch 24 similarly needs to perform a link enabling process to enable the link L2 to communicate with the main network 10 and the sub-network 20 (step 312). Conversely, if the standby network switch 24 continues to receive the ACK packet P1_ACK from the main network switch 22, it can be determined that the main network switch 22 is operating normally, and the standby network switch 24 may maintain a standby state.In addition, immediately after the standby network switch 24 is started up, if the ACK packet P1_ACK has not been received, the standby network switch 24 does not perform the link activation process, thereby avoiding unnecessary link switching and ensuring system stability.

[0027] On the other hand, if the time during which the polling packet P1 periodically transmitted from the standby network switch 24 is not received reaches a predetermined time (step 304), the main network switch 22 determines that the standby network switch 24 has been disabled, and executes a link enabling process to enable the link L1 to communicate with the sub-network 20 (step 306). Similarly, another situation may occur in which the polling packet P1 has not been received because all links (L5, L6) between the standby network switch 24 and the main network 10 are simultaneously disabled, and the main network switch 22 similarly needs to execute a link enabling process to enable the link L1 to communicate with the sub-network 20 (step 306). Also, if all links (L3, L4) connected to the main network 10 of the main network switch 22 are simultaneously disabled, the main network switch 22 similarly needs to execute a link enabling process to enable the link L1 to communicate with the main network 10 and the sub-network 20 (step 306). It should be noted that the main network switch 22 performs the link activation process only when the backup network switch 24 provides backup for the main network switch 22 via link L2. In other words, when the main network switch 22 and link L1 are operating normally and communication with the subnetwork 20 is being performed via link L1, there is no need to perform the link activation process for link L1.

[0028] The link activation process performed by the primary network switch 22 and the backup network switch 24 may be summarized as a link activation process 50, as shown in Figure 5. The link activation process 50 includes the following steps.

[0029] Step 500: The process begins.

[0030] Step 502: Switch the connection port connected to the subnetwork 20 to a forwarding state.

[0031] Step 504: According to the redundancy protocol A, a topology update packet TC1 is transmitted from the connection port connected to the main network 10.

[0032] Step 506: According to the redundancy protocol B, the topology update packet TC2 is transmitted from the connection port connected to the subnetwork 20.

[0033] Step 508: End the process.

[0034] FIG. 6 is a schematic diagram of an aspect of a link activation process 50 performed by the standby network switch 24 in the network system 1 according to an embodiment of the present invention. FIG. 6 illustrates how the standby network switch 24 performs the link activation process in step 312 when it determines in step 310 that the primary network switch 22 has become disabled. As shown in FIG. 6, according to the link activation process 50, in step 502, the standby network switch 24 first switches the state of the connection port 240 to a forwarding state (indicated by F). Then, the standby network switch 24 needs to notify the primary network 10 and the sub-network 20 that the network needs a topology update, respectively. In step 504, the standby network switch 24 sends a topology update packet TC1 in the primary network 10 via the connection ports 242, 244 according to the redundancy protocol A, and the network devices in the primary network 10 may update their media access control address tables (MAC address tables) based on the topology update packet TC1 (i.e., flush MAC). Meanwhile, in step 506, the backup network switch 24 may transmit a topology update packet TC2 to the subnetwork 20 via the connection port 240 according to the redundancy protocol B, and the network devices in the subnetwork 20 may update their media access control address tables based on the topology update packet TC2. This allows the networks of the primary network 10 and the subnetwork 20 to continue to operate according to the redundancy protocols A and B, respectively. Note that although Fig. 6 shows a case where the primary network switch 22 is disabled, it may also be applied to a case where the links L3 and L4 are disabled at the same time.

[0035] FIG. 7 is a schematic diagram of an aspect of a link activation process performed by the main network switch 22 in the network system 1 according to an embodiment of the present invention. FIG. 7 shows how the main network switch 22 performs the link activation process in step 306 when it determines in step 304 that the standby network switch 24 has been disabled. As shown in FIG. 7, according to the link activation process 50, in step 502, the main network switch 22 first switches the state of the connection port 220 to a forwarding state (indicated by F). Then, the main network switch 22 needs to notify the main network 10 and the subnetwork 20, respectively, that a topology update of the network is required. In step 504, the main network switch 22 sends a topology update packet TC1 in the main network 10 via the connection ports 222, 224 according to the redundancy protocol A, and the network devices in the main network 10 may update their media access control address tables based on the topology update packet TC1. Meanwhile, in step 506, the main network switch 22 may transmit a topology update packet TC2 to the sub-network 20 via the connection port 220 according to the redundancy protocol B, and the network devices in the sub-network 20 may update their media access control address tables based on the topology update packet TC2. This allows the networks of the main network 10 and the sub-network 20 to continue to operate according to the redundancy protocols A and B, respectively. Note that although Fig. 7 shows a case where the standby network switch 24 is disabled, it may also be applied to a case where the links L5 and L6 are disabled at the same time.

[0036] The above-described method for the standby network switch 24 to perform the polling process 30 may be summarized as a process 80, as shown in Figure 8. The process 80 includes the following steps.

[0037] Step 800: The process begins.

[0038] Step 802: A polling packet P1 is periodically transmitted.

[0039] Step 804: The ACK packet P1_ACK of the polling packet P1 is waited for.

[0040] Step 806: Determine whether the ACK packet P1_ACK is received. If YES, execute step 804; if not, execute step 808.

[0041] Step 808: Determine whether the number of times that the ACK packet P1_ACK has not been received reaches a predetermined number. If YES, execute step 810; if not, execute step 804.

[0042] Step 810: A link validation process is performed.

[0043] Step 812: End the process.

[0044] According to the process 80, the backup network switch 24 periodically transmits a polling packet P1 in the main network 10 via the connection ports 242, 244 (step 802) and waits for an ACK packet P1_ACK from the main network switch 22 (step 804). In this way, the backup network switch 24 continues to monitor the state of the main network switch 22. If the backup network switch 24 receives the ACK packet P1_ACK as scheduled, it determines that the main network switch 22 is operating normally, continues to wait for the next ACK packet P1_ACK, and may perform further determination if the ACK packet P1_ACK is not received (step 806). If the backup network switch 24 does not receive the ACK packet P1_ACK from the main network switch 22 consecutively for a predetermined number of times, it may determine that the main network switch 22 has become disabled and may perform a link activation process to back up the main network switch 22 (step 810). In this way, the backup network switch 24 switches the state of the connection port 240 to a forwarding state and notifies the main network 10 and the sub-network 20 of network topology updates according to the redundancy protocols A and B, respectively.

[0045] The above-described manner in which the primary network switch 22 performs the polling process 30 may be summarized as a process 90, as shown in Figure 9. The process 90 includes the following steps:

[0046] Step 900: The process begins.

[0047] Step 902: Wait for the polling packet P1.

[0048] Step 904: Determine whether the polling packet P1 has been received. If YES, execute step 906; if not, execute step 908.

[0049] Step 906: An ACK packet P1_ACK of the polling packet P1 is transmitted.

[0050] Step 908: Determine whether the time during which the polling packet P1 has not been received has reached a predetermined time. If YES, execute step 910; if not, execute step 902.

[0051] Step 910: A link validation process is performed.

[0052] Step 912: End the process.

[0053] According to the process 90, the main network switch 22 waits for a polling packet P1 from the standby network switch 24 and transmits an ACK packet P1_ACK of the polling packet P1 via the connection ports 222 and 224. This allows the main network switch 22 to feed back its own status and simultaneously monitor the status of the standby network switch 24. First, the main network switch 22 continues to wait for a polling packet P1 from the standby network switch 24 (step 902). If the main network switch receives the polling packet P1, it may determine that the standby network switch 24 is operating normally and continue to wait for the next polling packet P1. If the main network switch does not receive the polling packet P1, it makes a further determination (step 904). After receiving the polling packet P1, the main network switch 22 transmits an ACK packet P1_ACK to respond to the standby network switch 24 (step 906). If the time during which the polling packet P1 has not been received reaches a predetermined time (step 908), it may determine that the standby network switch 24 has been disabled and execute a link activation process to connect the subnetwork 20 (step 910). As a result, the main network switch 22 switches the state of the connection port 220 to a forwarding state, and notifies the main network 10 and the sub-network 20 of network topology updates according to the redundancy protocols A and B, respectively.

[0054] The polling process 30 thereby enables the primary network switch 22 and the backup network switch 24 in the network system 1 to monitor each other's status and enable links between the subnetworks 20 for communication as necessary.

[0055] Furthermore, in addition to monitoring the status of the main network switch 22 and the backup network switch 24, the network system 1 also needs to simultaneously monitor the status of the links L1, L2, and when either of the links L1, L2 becomes invalid, switch the link in a timely manner to maintain communication between the main network 10 and the subnetwork 20. In an embodiment of the present invention, one aspect of the backup method for network coupling in the network system 1 may be summarized as a link switching process 100, as shown in FIG. 10. The link switching process 100 includes the following steps:

[0056] Step 1000: The process begins.

[0057] Step 1002: The main network switch 22 detects the connection state of the link L1.

[0058] Step 1004: The main network switch 22 determines whether the connection state of the link L1 has changed. If YES, execute step 1006; if not, execute step 1002.

[0059] Step 1006: The main network switch 22 judges whether the connection state of the link L1 is a connection (link-up) state or a disconnection (link-down) state. If it is a connection state, execute step 1008, and if it is a disconnection state, execute step 1012.

[0060] Step 1008: The main network switch 22 sends a link confirmation packet LT1 via the link L1.

[0061] Step 1010: If the link confirmation packet LT1 has been received or the timer has expired, execute step 1012.

[0062] Step 1012: The main network switch 22 sends a link switching packet LC1.

[0063] Step 1014: When the link switching packet LC1 is received, the backup network switch 24 returns an ACK packet LC1_ACK.

[0064] Step 1016: The primary network switch 22 and the standby network switch 24 perform link switching.

[0065] Step 1018: End the process.

[0066] According to the process 100, the main network switch 22 needs to constantly monitor the connection state of the link L1 connected to the sub-network 20, and may determine whether the link L1 is in a connected or unconnected (disabled) state based on whether it receives an electrical signal of the link L1 (step 1002). If the state of the link L1 changes, the main network switch 22 needs to further determine the subsequent action (step 1004). When the state of the link L1 transitions from a connected state to a unconnected state, the backup network switch 24 performs backup and switches the connection link between the main network 10 and the sub-network 20 to the link L2 (steps 1012 to 1016). When the state of the link L1 transitions from a unconnected state to a connected state, the main network switch 22 further transmits a link confirmation packet LT1 to the sub-network 20 to confirm the state of the link L1, and switches the connection link between the main network 10 and the sub-network 20 to the link L1 (steps 1008 to 1016). If link switching is required, the main network switch 22 may send a link switching packet LC1 in the main network 10 via the connection ports 222, 224 to notify the backup network switch 24 of the switching of the links L1, L2 (step 1012). Upon receiving the link switching packet LC1, the backup network switch 24 sends an ACK packet LC1_ACK of the link switching packet LC1 in the main network 10 via the connection ports 242, 244 (step 1014) to perform link switching. In step 1016, the main network switch 22 and the backup network switch 24 need to perform link switching, respectively. In step 1016, similar to the link activation process 50 described above, the main network switch 22 and the backup network switch 24 change the state of the connection ports 220, 240 corresponding to the links L1, L2 connected to the sub-network 20, and send topology update packets TC1, TC2 to the main network 10 and the sub-network 20, respectively.

[0067] 11 and 12 are schematic diagrams of aspects of a link switching process 100 executed by the network system 1 according to an embodiment of the present invention. Here, FIG. 11 specifically illustrates a case where it is determined in step 1006 that the link L1 has transitioned from a connected state to a non-connected state. In step 1012, the main network switch 22 may transmit a link switching packet LC1 in the main network 10 via the connection ports 222 and 224. Next, in step 1014, upon receiving the link switching packet LC1, the backup network switch 24 returns an ACK packet LC1_ACK to the main network 10 via the connection ports 242 and 244, and performs link switching according to the instruction of the link switching packet LC1.

[0068] As shown in FIG. 12, when the spare network switch 24 receives the link switching packet LC1, it enables the link L2 to communicate with the sub-network 20 according to the instruction of the link switching packet LC1. Similar to the link enabling process 50, the spare network switch 24 needs to switch the connection port 240 connected to the sub-network 20 to a forwarding state (denoted by F). Then, the spare network switch 24 needs to notify the main network 10 and the sub-network 20 that the networks need a topology update, respectively. The spare network switch 24 may send a topology update packet TC1 in the main network 10 via the connection ports 242, 244 according to a redundancy protocol A, and the network devices in the main network 10 may update their media access control address tables based on the topology update packet TC1. Meanwhile, the spare network switch 24 may send a topology update packet TC2 to the sub-network 20 via the connection port 240 according to a redundancy protocol B, and the network devices in the sub-network 20 may update their media access control address tables based on the topology update packet TC2.

[0069] Meanwhile, when the main network switch 22 receives the ACK packet LC1_ACK from the backup network switch 24, the main network switch 22 needs to switch the connection port 220 connected to the sub-network 20 to a blocked state (indicated by B), and also needs to notify the main network 10 and the sub-network 20 that a topology update of the network is required. Since the link L1 has been disabled, in this case, the main network switch 22 only needs to send the topology update packet TC1 in the main network 10 via the connection ports 222, 224 according to the redundancy protocol A, so that the network devices in the main network 10 can update their media access control address tables based on the topology update packet TC1.

[0070] 13A, 13B, and 14 are schematic diagrams of other aspects of the link switching process 100 executed by the network system 1 according to an embodiment of the present invention. Here, Fig. 13A and Fig. 13B specifically show a case where it is determined in step 1006 that the link L1 has transitioned from a non-connected state to a connected state. In this case, communication between the primary network 10 and the subnetwork 20 is switched from the link L2 to the link L1 by the primary network switch 22, and the standby network switch 24 waits again.

[0071] In FIG. 13A, the main network switch 22 may further transmit a link confirmation packet LT1 to the sub-network 20 to confirm the state of the network switch 26 connected to the link L1 on the sub-network. In step 1008, the main network switch 22 may first transmit the link confirmation packet LT1 via the link L1 via the connection port 220. The link confirmation packet LT1 transmitted by the main network switch 22 on the main network 10 may be transmitted sequentially via the link L1, the sub-network 20, and the link L2, and then returned to the main network 10 again, and finally received by the main network switch 22 via the connection port 222 or 224. Next, in step 1010, the main network switch 22 waits for the link confirmation packet LT1 forwarded via the sub-network 20 and returned to the main network 10, and can confirm that the link L1 and the network switch 26 connected to the link L1 on the sub-network 20 are ready, and may immediately perform link switching. On the other hand, if the main network switch 22 has not received the link confirmation packet LT1 transmitted from itself, it may wait for a timer to expire before performing link switching. If the link confirmation packet LT1 has been received or the timer has expired, in step 1012, the main network switch 22 may transmit a link switching packet LC1 in the main network 10 via the connection ports 222, 224 to notify the backup network switch 24 of the switching of the links L1, L2. Next, in step 1014, if the link switching packet LC1 has been received, the backup network switch 24 returns an ACK packet LC1_ACK in the main network 10 via the connection ports 242, 244, and performs link switching according to the instruction of the link switching packet LC1.

[0072] As shown in FIG. 13B, in one aspect, when the network switch 26 connected to the link L1 receives the link confirmation packet LT1 transmitted by the main network switch 22, the network switch 26 may transmit an ACK packet LT1_ACK of the link confirmation packet LT1 to the main network switch 22 via the link L1. In step 1010, the main network switch 22 waits for the ACK packet LT1_ACK returned from the network switch 26 or the expiration of a timer. If the network switch 26 can identify the link confirmation packet LT1, the network switch 26 returns the ACK packet LT1_ACK. The main network switch 22 may confirm through the ACK packet LT1_ACK that the link L1 and the network switch 26 are ready and immediately perform link switching. If the network switch 26 cannot identify the link confirmation packet LT1, the main network switch 22 does not receive the ACK packet LT1_ACK from the network switch 26. In this case, the main network switch 22 waits for the expiration of the timer before performing link switching.

[0073] In FIG. 14, when the standby network switch 24 receives the link switching packet LC1, it cuts off the link L2 according to the instruction of the link switching packet LC1 and stops communication with the sub-network 20. Similar to the link enabling process 50, the standby network switch 24 needs to switch the connection port 240 connected to the sub-network 20 to a cutoff state. Next, the standby network switch 24 needs to notify the primary network 10 and the sub-network 20 that the networks require a topology update, respectively. The standby network switch 24 sends a topology update packet TC1 to the primary network 10 via the connection ports 242, 244 according to a redundancy protocol A so that the network devices in the primary network 10 can update their media access control address tables based on the topology update packet TC1. Meanwhile, the standby network switch 24 sends a topology update packet TC2 to the sub-network 20 via the connection port 240 according to a redundancy protocol B so that the network devices in the sub-network 20 can update their media access control address tables based on the topology update packet TC2.

[0074] On the other hand, when the main network switch 22 receives the ACK packet LC1_ACK from the standby network switch 24, the main network switch 22 must switch the connection port 220 connected to the sub-network 20 to a forwarding state, and similarly notify the main network 10 and the sub-network 20 that a topology update is required. In this case, the main network switch 22 must transmit a topology update packet TC1 in the main network 10 via the connection ports 222 and 224 according to a redundancy protocol A so that the network devices in the main network 10 can update their media access control address tables based on the topology update packet TC1. On the other hand, the main network switch 22 transmits a topology update packet TC2 to the sub-network 20 via the connection port 220 according to a redundancy protocol B so that the network devices in the sub-network 20 can update their media access control address tables based on the topology update packet TC2.

[0075] Thereby, the network system 1 monitors the states of the links L1 and L2, and switches the links in a timely manner according to the state of the link L1 so as to maintain the communication between the primary network 10 and the sub-network 20. In the embodiment of the present invention, the primary network switch 22 can further confirm the connection state of the link L1 via the link confirmation packet LT1 or the ACK packet LT1_ACK of the link confirmation packet, and can notify the backup network switch 24 of the link switching via the link switching packet LC1. In addition, via the topology update packets TC1 and TC2, the primary network switch 22 and the backup network switch 24 can notify the primary network 10 and the sub-network 20, respectively, according to different redundancy protocols to update the media access control address tables.

[0076] The above-described manner in which the main network switch 22 performs the link switching process 100 may be summarized as a process 150. As shown in FIG.

[0077] Step 1500: The process begins.

[0078] Step 1502: The connection state of the link L1 is detected.

[0079] Step 1504: Determine whether the connection state of link L1 has changed. If YES, execute step 1506; if not, execute step 1502.

[0080] Step 1506: Determine whether the connection state of the link L1 is a connected state or a disconnected state. If it is a connected state, execute step 1508; if it is a disconnected state, execute step 1518.

[0081] Step 1508: Transmit a link confirmation packet LT1 via link L1.

[0082] Step 1510: If the link confirmation packet LT1 has been received or the timer has expired, execute step 1512.

[0083] Step 1512: Send a link switching packet LC1.

[0084] Step 1514: If the ACK packet LC1_ACK of the link switching packet LC1 is received or the timer expires, execute step 1516.

[0085] Step 1516: The connection port 220 connected to the sub-network 20 is switched to a forwarding state.

[0086] Step 1518: Send link switch packet LC1.

[0087] Step 1520: If the ACK packet LC1_ACK of the link switching packet LC1 is received or the timer expires, execute step 1522.

[0088] Step 1522: The connection port 220 connected to the sub-network 20 is switched to a blocking state.

[0089] Step 1524: Send a topology update packet TC1 via the connection ports 222, 224 according to redundancy protocol A, and send a topology update packet TC2 via the connection port 220 according to redundancy protocol B.

[0090] Step 1526: End the process.

[0091] The above-described manner in which the standby network switch 24 performs the link switching process 100 may be summarized as a process 160, as shown in Figure 16. The process 160 includes the following steps.

[0092] Step 1600: The process begins.

[0093] Step 1602: Wait for the link switch packet LC1.

[0094] Step 1604: Determine whether or not the link switching packet LC1 has been received. If YES, execute step 1606; if not, execute step 1602.

[0095] Step 1606: An ACK packet LC1_ACK of the link switching packet LC1 is transmitted.

[0096] Step 1608: Based on the link switching packet LC1, determine whether to enable or block the link L2. If the link L2 is to be enabled, execute step 1610; if the link L2 is to be blocked, execute step 1612.

[0097] Step 1610: The connection port 240 connected to the sub-network 20 is switched to a forwarding state.

[0098] Step 1612: The connection port 240 connected to the sub-network 20 is switched to a disconnected state.

[0099] Step 1614: Send a topology update packet TC1 via the connection ports 242, 244 according to redundancy protocol A, and send a topology update packet TC2 via the connection port 240 according to redundancy protocol B.

[0100] Step 1616: End the process.

[0101] In the embodiment of the present invention, messages are exchanged between the main network switch 22 and the standby network switch 24 via the polling packet P1, the ACK packet P1_ACK of the polling packet P1, the link switching packet LC1, and the ACK packet LC1_ACK of the link switching packet LC1, and are transmitted via the main network 10 and do not flow into the sub-network 20. However, if the sub-network 20 is a chain network, the sub-network 20 does not have a sufficient redundancy mechanism to deal with the occurrence of a link down in the network, so that a part of the network communication may be interrupted when a link down occurs in the chain network. In this case, the embodiment of the present invention transmits the polling packet, the ACK packet of the polling packet, the link switching packet, and the ACK packet of the link switching packet via the chain network to exchange messages between the main network switch 22 and the standby network switch 24. This also monitors the network status of the chain network. In addition, the method of transmitting polling packets, ACK packets of the polling packets, link switching packets, and ACK packets of the link switching packets via a chained network to pass messages between the main network switch 22 and the backup network switch 24 can be applied to networks of various different network topologies and is not limited to chained networks.

[0102] FIG. 17 is a schematic diagram showing an embodiment of the present invention in which the sub-network 20 is a chain network. In FIG. 17, the network switches 26 and 28 are connected to the head and tail of the chain network, respectively, and are connected to the main network switch 22 and the backup network switch 24 via links L1 and L2, respectively. Generally, the connection port 220 of the main network switch 22 is in a forwarding state to perform communication between the main network 10 and the chain network, and the connection port 240 of the main network switch 22 is in a blocking state and is on standby as a backup for the main network switch 22. According to the polling process, the main network switch 22 periodically sends a polling packet P2 to the chain network via link L2, and the main network switch 22 receives the polling packet P2 from the chain network via link L1. Similarly, the main network switch 22 also sends an ACK packet P2_ACK of the polling packet P2 to the chain network via link L1, and the backup network switch 24 also receives an ACK packet P2_ACK from the chain network via link L2. When the time during which the main network switch 22 does not receive the polling packet P2 reaches a predetermined time, the main network switch 22 may determine that the backup network switch 24 has been disabled or that the network has stopped functioning due to a link down in the chained network. In this case, it is necessary to enable the link L1 so that all network devices in the chained network can connect to the network. Similarly, when the backup network switch 24 has been sending the polling packet P2 and has not received the ACK packet P2_ACK a predetermined number of times, the backup network switch 24 may determine that the main network switch 22 has been disabled or that the network has stopped functioning due to a link down in the chained network. In this case, it is necessary to enable the link L2 so that all network devices in the chained network can connect to the network.Similarly, the link switching packet LC2 and its ACK packet LC2_ACK are also sent through the chained network according to the link switching process 100. When the main network switch 22 sends the link switching packet LC2 and does not receive the ACK packet LC2_ACK a predetermined number of times, the main network switch 22 may determine that the standby network switch 24 is disabled or the network is not functioning due to a link down in the chained network. In this case, the link L1 needs to be enabled so that all network devices in the chained network can connect to the network.

[0103] FIG. 18 is a schematic diagram of an embodiment of the present invention in which the subnetwork 20 is a chain network, showing a case where one link down occurs in the chain network. In this case, the spare network switch 24 periodically sends a polling packet P2 to the chain network via the link L2, but does not receive an ACK packet P2_ACK from the main network switch 22. Therefore, the spare network switch 24 needs to enable the link L2 to ensure that all network devices in the link network are connected to the network. According to the link enabling process 50, in step 502, the spare network switch 24 first switches the state of the connection port 240 to a forwarding state. Then, the spare network switch 24 needs to notify the main network 10 and the chain network that a topology update is required, respectively. In step 504, the spare network switch 24 sends a topology update packet TC1 to the main network 10 via the connection ports 242, 244 according to the redundancy protocol A, so that the network devices in the main network 10 can update their media access control address tables based on the topology update packet TC1. Meanwhile, in step 506, the standby network switch 24 transmits the topology update packet TC2 to the link network via the connection port 240 according to the redundancy protocol B so that the network devices in the link network can update their media access control address tables based on the topology update packet TC2. This makes it possible to ensure communication between the chain network and the main network 10. Note that although Fig. 18 shows a case where some links in the chain network go down, the same applies to a case where the main network switch 22 goes down.

[0104] In addition, in the embodiment of the present invention, all control packets must be transmitted and received via a connection port connected to the main network 10 or a connection port connected to the sub-network 20. Taking the main network switch 22 as an example, all control packets must be transmitted and received via a connection port 220 connected to the sub-network 20 and connection ports 222 and 224 connected to the main network 10. If the main network switch 22 receives a control packet via a connection port other than the connection ports 220, 222, and 224, it may be determined that an incorrect network connection method occurs and a network loop may be caused. In this case, the main network switch 22 switches the state of the connection port 220 to a blocking state and continues the state for a predetermined time, and returns an error message. Similarly, taking the standby network switch 24 as an example, all control packets must be transmitted and received via a connection port 240 connected to the sub-network 20 and connection ports 242 and 244 connected to the main network 10. If the standby network switch 24 receives a control packet via a connection port other than the connection ports 240, 242, and 244, it may be determined that an incorrect network connection method occurs and a network loop may be caused. In this case, the standby network switch 24 switches the state of the connection port 240 to a disconnected state, continues this state for a predetermined period of time, and returns an error message, thereby enabling the embodiment of the present invention to detect an incorrect network connection method.

[0105] FIG. 19 is a schematic diagram of a network device 190 according to an embodiment of the present invention. The network device 190 may be used to realize the main network switch 22 and the standby network switch 24 according to an embodiment of the present invention. As shown in FIG. 19, the network device 190 may include a processing unit 1900 and a storage unit 1902. The processing unit 1900 may be a general-purpose processor, a microprocessor, an application specific integrated circuit (ASIC), or the like, or a combination thereof. The storage unit 1902 may be any data storage device connected to the processing unit 1900, for storing a program code 1904, and for reading and executing the program code 1904 by the processing unit 1900. For example, the storage unit 1902 may be, but is not limited to, a read only memory (ROM), a flash memory, a random access memory (RAM), a hard disk and an optical data storage device, a non-volatile storage unit, and the like. In addition, the network device 190 further includes a plurality of connection ports (not shown) for connecting a plurality of network devices between the sub-network and the main network.

[0106] The network device 190 is used to represent elements necessary for implementing the embodiment of the present invention, and those skilled in the art may make various modifications and adjustments, but are not limited to these. For example, when the primary network switch 22 is implemented in the network device 190, the processes 50, 90, 150 of the network-coupled backup method are compiled into a program code 1904 and stored in the storage unit 1902, and the network-coupled backup method is executed by the processing unit 1900. When the standby network switch 24 is implemented in the network device 190, the processes 50, 80, 160 of the network-coupled backup method are compiled into a program code 1904 and stored in the storage unit 1902, and the network-coupled backup method is executed by the processing unit 1900. In addition, the storage unit 1902 is also used to store data necessary for implementing the network-coupled backup method, but is not limited to these.

[0107] From the above, according to the network coupling architecture, network switch and backup method thereof of the present invention, the coupled different networks can be connected and communicate with each other even when they are operating according to different redundancy protocols, and can achieve stable performance without interfering with each other. Here, the network switches can monitor the network status through control packets, such as polling packets, connection confirmation packets, and link switching packets, and perform information interaction to achieve the purpose of backup. By transmitting topology update packets of different redundancy protocols for each network, information that each network link has been updated can be notified without affecting the operation of each redundancy protocol. In addition, when a chained network is coupled, a mechanism for monitoring and backing up the chained network can be achieved by changing the sending direction of the polling packets and link switching packets. In this way, the present invention improves the shortcomings of the prior art.

[0108] The above describes the preferred embodiment of the present invention, but all equivalent modifications and variations based on the claims of the present invention belong to the scope of the present invention. [Explanation of symbols]

[0109] A to D: Redundancy protocols 1: Network system 10: Main network 12_1~12_3: Sub-network 14_1~14_3: Main network switch 16_1~16_3: Standby network switches N1~N3: Network L1~L6: Link 20: Subnetwork 22: Main network switch 24: Spare network switch 26, 28: Network switch 220, 222, 224, 240, 242, 244: Connection ports 30: Process 300~314: Step P1: Polling packet P1_ACK: ACK packet for polling packet 50: Process 500~508: Step TC1, TC2: Topology update packets 80, 90, 100: Process 800~812, 900~912, 1000~1018: Step LC1: Link switching packets LC1_ACK: Link switching packet ACK packet LT1: Link confirmation packet LT1_ACK: ACK packet for link confirmation packet 150, 160: Process 1500~1526, 1600~1616: Step P2: Polling packet P2_ACK: ACK packet for polling packet LC2: Link switching packets LC2_ACK: Link switching packet ACK packet 190: Network equipment 1900: Processing section 1902: Storage section 1904: Program code

Claims

1. A main network switch configured in a main network operating in accordance with a first redundancy protocol and used to couple a sub-network operating in accordance with a second redundancy protocol, comprising: at least one first connection port for connecting to said main network; a second connection port for connecting to the sub-network; a processing unit for executing program code; a storage unit connected to the processing unit and storing a program code for instructing the processing unit to execute a backup method for network connection; The backup method includes: transmitting a first control packet via the at least one first connection port; receiving an ACK packet for the first control packet when the first control packet is transmitted; when the ACK packet of the first control packet is received, switching a state of the second connection port, transmitting a second control packet according to the first redundancy protocol via the at least one first connection port to update a media access control address table (MAC address table) of the main network, and transmitting a third control packet according to the second redundancy protocol via the second connection port to update a media access control address table of the sub-network.

2. 2. The main network switch according to claim 1, wherein when the processing unit instructs the program code to execute the backup method, if the link of the second connection port becomes invalid (link-down), the state of the second connection port is switched to a blocking state.

3. 2. The main network switch according to claim 1, wherein when the processing unit instructs the program code to execute the backup method, if a main line switching condition is satisfied, the state of the second connection port is switched to a forwarding state, and after transmitting a fourth control packet via the second connection port, if the fourth control packet has been received via the at least one first connection port or a timer has expired, the main network switch transmits the first control packet via the at least one first connection port.

4. The main network switch of claim 3, wherein the main line switching condition is that the link of the second connection port resumes operation (link-up) or all of the links of the at least one first connection port become invalid.

5. The backup method includes: receiving a fifth control packet from a standby network switch in the primary network that is connected to the sub-network; The main network switch of claim 3 , further comprising: upon receipt of the fifth control packet, transmitting an ACK packet for the fifth control packet.

6. 6. The main network switch according to claim 5, wherein the main line switching condition is that a time period during which the fifth control packet has not been received reaches a predetermined time period.

7. 6. The main network switch of claim 5, wherein the ACK packets for the first control packet and the fifth control packet are transmitted over the sub-network via the second connection port.

8. The main network switch of claim 7 , wherein the sub-network is a chain network.

9. 9. The main network switch of claim 8, wherein the main line switching condition is that a time during which the fifth control packet has not been received has reached a predetermined time, or that an ACK packet for the first control packet has not been received after the first control packet has been transmitted.

10. further comprising a third communication port; The backup method includes:

2. The main network switch of claim 1, further comprising: if the main network switch receives any control packet via the third communication port, switching the state of the second connection port to a blocking state and maintaining the state for a predetermined time, and returning an error message.

11. A standby network switch configured in a primary network operating in accordance with a first redundancy protocol and used to couple a sub-network operating in accordance with a second redundancy protocol, at least one first connection port for connecting to said main network; a second connection port for connecting to the sub-network; a processing unit for executing program code; a storage unit connected to the processing unit and storing a program code for instructing the processing unit to execute a backup method for network connection; The backup method includes: switching a state of the second connection port; transmitting first control packets according to the first redundancy protocol via the at least one first connection port to update a media access control address table (MAC address table) of the primary network, and transmitting second control packets according to the second redundancy protocol via the second connection port to update a media access control address table of the sub-network.

12. 12. The backup network switch of claim 11, wherein when the processing unit receives a third control packet when instructed by the program code to execute the backup method, the backup network switch transmits an ACK packet of the third control packet via the at least one first connection port, and switches the state of the second connection port to a blocking state or a forwarding state.

13. The standby network switch of claim 12 , wherein the ACK packet of the third control packet is transmitted over the sub-network via the second connection port.

14. The standby network switch of claim 13 , wherein the sub-network is a chain network.

15. 12. The backup network switch of claim 11, wherein when the processing unit instructs the program code to execute the backup method, if all links of the at least one first connection port become invalid, the state of the second connection port is switched to a forwarding state.

16. When the processing unit instructs the execution of the backup method by the program code stored in the storage unit, periodically transmitting a fourth control packet via the at least one first connection port; 12. The standby network switch of claim 11, further comprising: executing the backup method and switching the state of the second connection port to a forwarding state when a number of times in the main network that an ACK packet for the fourth control packet from a main network switch connected to the sub-network has not been received reaches a predetermined number.

17. 17. The standby network switch of claim 16, wherein a fourth control packet is transmitted over the sub-network via the second connection port.

18. 20. The standby network switch of claim 17, wherein the sub-network is a chain network.

19. further comprising a third communication port; 12. The standby network switch of claim 11, wherein when the standby network switch receives any control packet via the third communication port, the standby network switch switches the state of the second connection port to a blocked state and continues the state for a predetermined time, and returns an error message.

20. A network architecture for network interconnection, comprising: a sub-network operating according to a first redundancy protocol; a primary network operating according to a second redundancy protocol; a main network switch provided in the main network, the main network switch being connected to the main network via at least one first connection port and connected to the sub-network via at least one second connection port; a standby network switch provided in the main network and connected to the main network via at least one third connection port and connected to the sub-network via a fourth connection port; The primary network switch and the standby network switch execute a backup method for network coupling; The backup method includes: the primary network switch transmitting a first control packet via the at least one first connection port; When the first control packet is received, the standby network switch transmits an ACK packet for the first control packet to switch a link, transmits a second control packet according to the second redundancy protocol via the at least one third connection port to update a media access control address table (MAC address table) of the primary network, and transmits a third control packet according to the first redundancy protocol via the fourth connection port to update a media access control address table of the sub-network; and when the ACK packet for the first control packet is received, the main network switch switches links and transmits a fourth control packet according to the second redundancy protocol via the at least one first connection port to update a media access control address table of the main network, and transmits a fifth control packet according to the first redundancy protocol via the second connection port to update a media access control address table of the sub-network.

21. 21. The network architecture of claim 20, wherein when the main network switch and the backup network switch execute the backup method, if a link of the second connection port of the main network switch becomes inactive (link-down), the link is switched.

22. 21. The network architecture of claim 20, wherein when the main network switch and the standby network switch execute the backup method, if a main line switching condition is met, the main network switch transmits the first control packet through the at least one first connection port after transmitting a sixth control packet through the second connection port, or if a timer expires, the main network switch transmits the first control packet through the at least one first connection port.

23. 23. The network architecture of claim 22, wherein the main line switching condition is that a link of the second connection port resumes operation (link-up) or all links of the at least one first connection port become invalid.

24. the standby network switch periodically transmits a seventh control packet via the at least one third connection port; 23. The network architecture of claim 22, wherein the main network switch, upon receipt of the seventh control packet, transmits an ACK packet for the seventh control packet.

25. 25. The network architecture of claim 24, wherein the main line switching condition is that the main network switch has not received the seventh control packet for a predetermined period of time.

26. the ACK packet of the first control packet and the seventh control packet is transmitted over the sub-network via the second connection port; 25. The network architecture of claim 24, wherein the ACK packet of the first control packet and the seventh control packet are transmitted over the sub-network via the fourth connection port.

27. 27. The network architecture of claim 26, wherein the sub-network is a chain network.

28. 28. The network architecture of claim 27, wherein the main line switching condition is that a time during which the main network switch has not received the seventh control packet has reached a predetermined time, or that an ACK packet for the first control packet has not been received after the first control packet has been transmitted.

29. 25. The network architecture of claim 24, wherein the standby network switch executes the backup method and switches the state of the fourth connection port to a forwarding state when a number of times that the standby network switch does not receive an ACK packet for the seventh control packet from the primary network switch reaches a predetermined number.

30. 25. The network architecture of claim 24, wherein the standby network switch switches a state of the fourth connection port to a forwarding state when all links of the at least one third connection port become invalid.

Images