(First of all, I would like to emphasize one point to you. The PPP you are talking about here is not to configure your server as a server that provides dial-in services, but that users can dial-up Internet access through the server. In short, the server can automatically Dial-up Internet access, also known as dial-up on demand. Why do you want to introduce this configuration to everyone? Because although many enterprises now use DDN to surf the Internet, Modem)