To enable the server to transmit data on the public network, you must first know your own network access method. If it is a public network static IP address, then directly set the server's IP address, subnet mask, and gateway to the static address provided by the ISP to browse normally. In addition, both the most widely used network access methods, ADSL and residential broadband, require an authentication process. Authentication can be done through some smart devices such as a PC or a small router. If it is inside the LAN, there is a public IP address, and the outside network cannot see the inside of the network. In this case, some settings are required on the access server. Solutions： If you use it inside an office or building LAN, but still want to access the network video server in other cities, you can use the machine connected to the Internet to do a forwarding. Specifically, the method of port mapping can be used to complete the forwarding of information packets. Some of the more popular port mapping software just need to perform simple settings, such as: Portmap, Portunnel. Select all IPs in the visited IP address, and then fill in the device's internal LAN address for the back-end IP address. It is also a good solution to choose a router as the forwarding device in case of no PC. Most routers now have a port mapping function, or DMZ. Just specify the DMZ address as that of the device. Set up a VPN server as a virtual private network server, and then dial in the remote client. You can access the internal host after connecting.