This project is to establish a reliable and secure communication system. The main functions are:
The network structure of the communication system is shown in the figure below.
The entire network is divided into a lower device layer, a transport network layer, a communication platform layer, and a central application layer.
The lower device layer includes a signal device and a SLK-302 transmission device to implement access to the lower end data. MAC address binding of the service device in the SLK-302 transmission device to prevent the intrusion of the illegal terminal;
The transport network layer includes two networks, wired and wireless. Both networks implement the connection between the lower end and the center in the VPDN mode. Implement a dual channel data transmission channel;
The communication platform includes an AAA authentication server, an access router, a switch, and a network management platform to implement dual channel communication access and management functions. The AAA authentication server is responsible for the authentication and management of the lower wireless device. The access router is responsible for accessing the lower wireless device link. The switch is responsible for consolidating the two links. The network management platform is responsible for remote management and configuration of the lower communication device;
The central application layer mainly includes devices such as an application server, a database server, and a client, and mainly implements management functions for the lower end signal.
The lower signal is connected to the transmission device SLK-302 via a serial or Ethernet interface. The SLK-302 wireless router automatically detects the connection status with the central wired network. Under normal circumstances, the connection between the lower end signal and the central application server is realized through the wired network. If the wired network cable fails, the SLK-302 device automatically switches to the wireless network for service data transmission. Once the wired network cable is detected to be normal, the SLK-302 device will automatically switch back to the wired network for data transmission.
In the upper communication platform, the access router is responsible for accessing the wireless network data. The switch is responsible for accessing the wired network cable and the wireless network cable data, and can convert the IP addresses of each of the lower-end devices in the wired and wireless networks into one IP address according to the configuration requirements, so that the central application server can identify the lower end. That is to say, the lower-end signal device corresponding to the central application server has only one IP address, and whether it is connected from the wired or the wireless network, it is handed over to the switch for processing.
The data flow is shown in the figure below.