Industrial router working process and principle

An industrial router is a network device that connects multiple networks or segments. Industrial routers can "transform" data information between different networks or network segments so that they can "read" each other's data, thereby forming a larger network. Industrial routers are the main node equipment of the Internet. Industrial routers determine data forwarding through routing.

    The main work of industrial routers includes three aspects

    1) Dynamically generate and maintain the routing table;

    2) Find the routing table according to the IP address information in the received message, and determine the best path for forwarding data;

    3) Data forwarding.

    Industrial routers work at the third layer of the OSI seven-layer protocol

    Its main task is to receive data packets from the network interface and determine the address to be forwarded to the next destination based on the destination address contained in the data packet. Therefore, the industrial router must first look up its destination address in the forwarding routing table. If the destination address is found, the next MAC address is added before the packet frame. At the same time, the TTL (time to live) field of the IP packet header is reduced, and the checksum is recalculated. When data packets are sent to the output port, they need to wait before being transmitted to the output link.

    Industrial routers can look up the routing table in the device according to a certain routing communication protocol while working. If there is more than one path to a particular node, the basic predetermined routing rule is to select the best (or most economical) transmission path. Since various network segments and their interconnections may change due to environmental changes, routing information is usually updated regularly according to the provisions of the routing information protocol used.

    The specific process of industrial routers

    Usually, the main job of an industrial router is to store and forward data packets. The specific process is as follows:

    1) When the data packet arrives at the industrial router, according to the type of network physical interface, the industrial router will call the corresponding link layer function module to interpret the link layer protocol header used to process the data packet. This step is relatively simple and is mainly used to verify the integrity of the data, such as CRC check and frame length check.

    2) After the link layer completes the integrity verification of the data frame, the industrial router starts to process the IP layer of the data frame. This process is the core of the industrial router function. According to the target IP address of the IP data packet header in the data frame, the industrial router looks up the IP address of the next hop in the routing table. At the same time, the TTL (time to live) field of the IP packet header begins to decrement and the checksum is recalculated.

    3) According to the next hop IP address found in the routing table, the IP data packet is sent to the corresponding output link layer, encapsulated with the corresponding link layer header, and finally sent through the output network physical interface.

    Conclusion on the working principle of industrial routers

    The main job of an industrial router is to find the best transmission path for each data packet passing through the industrial router, and to effectively deliver the data packet to the target site. From this perspective, choosing the best path strategy or choosing the best routing algorithm is the key to industrial routers. In order to accomplish this task, a routing table containing data on various transmission paths is stored in an industrial router for use in routing selection. The above process describes the main and critical working processes of the industrial router, but does not describe other additional features, such as access control, network address translation, and queuing priority.