The paper present a solution of remote RS232 communication over the Internet. The problem is related to changing the IP address that each network device has. It is about communication between a computer, which manages or collects data about a process, and the USR TCP232-200 serial communication device. When connecting a serial communication device to the Internet, the device receives a temporary IP address that changes. To avoid this problem, a VPN server was created on the Raspberry Pi computer that connects to the local network with the USR TCP232-200 serial communication device. By connecting a remote client to a VPN server, a private network is provided over the public network infrastructure. This has solved the problem of changing the IP address. The paper begins with an introduction in which shortcomings represent issues related to RS232 communication over the Internet. Then follows the section where LAN / WAN communication is described and a description of all the protocols without which Internet communication is not possible. Below is an IP address, DNS, DDNS, VPN. A specific example of RS232 communication over the Internet was then elaborated. In the end, the solution to the problem is accompanied by a practical part in which the structure and operation of the realized system are shown step by step. In the very end of the work, there is an analysis of the results accompanied by conclusions based on the results obtained.