What are the ways to distribute the Internet remotely?

Question

Computer networks

At this time, I distribute the Internet through the ffproxy proxy server (in the settings they enter the address of this proxy server and sit on the Internet), but this method is not relevant. It is necessary to implement the connection differently (the client connects to the server). The server should monitor the connection, consumed traffic, and other useful things. On the client side, a certain client program must be installed that would connect to the server and let it into the Internet.
Cons in ffproxy: not all protocols are supported, slow, traffic goes through this proxy.

Answer 1

raise the VPN server and let traffic through it.

Answer 2

Any billing system can do it out of the box. The easiest option is to install mikrotik (software or hardware, it doesn't matter), he knows out of the box what you need for a small grid.

Answer 3

1) Mikrotik + netflow collector
2) Kerio
3) T-meter
4) TrafficInspector
5) PfSense
This is just what I am at least slightly familiar with.