I don't understand why these systems need to be on the Internet. If engineers really need to be able to connect to them remotely, those seeking to connect shou

I don't understand why these systems need to be on the Internet. If engineers really need to be able to connect to them remotely, those seeking to connect shouldn't be establishing the connection, just requesting that one be established. Like the old modem connections where you just wait for a call at an already known phone number.