It is simple to make your computer in your home LAN accessible from internet.

The pre-requisite would be understanding how Network Address Translation works. To make the dynamic IP of ISP provide to your home internet access, feel free to research into finding Dynamic DNS providers. This will make it easier than using websites like whatismyip.com . And you just need to fire up the RDP client, and use the Dynamic DNS FQDN which will be always pointing to your static IP.

Depending on the network equipment used in your home or provided by your Internet Service Provider (ISP), you may need to look for NAT or in my case IPv4 port mapping.

The screenshot above, shows how to create a NAT mapping or a IPv4 port mapping for a computer with LAN IP, 192.168.100.12, take note that the port of RDP is 3389 and the protocol used is TCP. Hence, the internal port must be numbered 3389.

External port set to 3389 are for the sake of simplicity.

If there are more host in your LAN need to be accessible from the internet remotely using RDP, there is no need to change the default port of RDP of your host.

Instead, use the known port that is not blocked by your ISP. Example assuming that higher port numbers are not blocked by your ISP, you could use 13389, or 23389, or 33389 or 43389, or 53389 or 63389, as long as it is not more than 65535 or lesser than 1024. Those port number can be used as the External port number, while maintaining the internal port number to 3389.