These days I take the availability of a VPN for granted, but in the early days of my Internet experience things were different. At the time Demon Internet ran actual Points of Presence (POPs) which were modems sat at the end of a leased line, usually run by some sort of early enthusiast. The leased line would normally connect to something like a PIPEX backbone, and the modems would allow early internet punters to call a regional number (between local and long distance) to get internet access.
Back then sharing a 64K backbone wasn't a problem, especially when a fast modem was 14.4k, the norm being quite a bit less than that.
I've just covered the chapter in my Windows 2000 Server book on Routing and Remote Access, the thing you can manage dial-up access from. Delightful settings such as ring-back options, dial-in hours, and IP allocation to remote connecting users - the stuff of legends.
Even VPN stuff, though I think this has been a bit different with the advent of ISA server.