Ok, so I won't use "theoretical" then, lol. And this all pretty much answers my question, thanks
You know, something that's always bugged me is the fact that, if you look at the way the Internet is structured today, the way Uplink presents it is a little unrealistic.
You probably read the backhistory of the game - Arunmor basically built the "Internet" (it's actually the AWAN) in which you hack and play. The thing is, they designed it for security - and I can't think of a logical reason to, for example, expose your central mainframe to the wider network.
Sure, you need to connect via a "trusted" source, but that's really just another bounce point. In the real world, I'm sure that companies would hide their central mainframes behind very well-protected LANs.
Also, they're called "Internal Service Machine" for a very good reason. Even in 2020, I'm sure that individuals would log on to their company's LAN router, authenticate, then connect to their ISM.
And realistically, any company's public access server would either be hosted from within the LAN (opening port 80 to the public), with the smaller companies making use of remote hosting.
So apart from Government systems (and banks), every company only really needs 2 "exposed" systems - a LAN, and a PAS. And in order to do anything to a company, you'll need to hack in to a LAN.
Missions like Steal The File would be structured pretty much the same, really. Connect to the LAN's IP, hack your way past the public frontend, and you're at the ISM.
Wouldn't structuring the game in this way reduce the number of systems required to create a realistic world? I'm guessing it could also allow for a few more companies & people, hence deeper game world. Just a thought.
Edit: Also, it makes little sense that someone's PC could be located in London, and their voice phone system located in southern Pakistan. In a VOIP-connected world, you should be able to phone someone by dialing their PC IP. And then hack in with PCForce.