[arch-general] Single Person ISP?

[Brendan Long]

So recently Verizon has stopped letting me do free tethering and I've
been looking for a replacement. Apparently all of the free ISPs I can
find all require that you use their shitty Windows program to connect,
so I decided, "I have a phone line, a modem and an internet connection,
maybe I can make my own ISP".

Basically, I want to take a computer with a dialup modem and an ethernet
connection to a cable modem and make it so whenever someone calls, the
computer picks up and acts like an ISP (requests username/password, then
forwards all requests to the cable modem).

Obviously, it wouldn't be that great (added latency, phone line won't
work while it's active), but it's at least theoretically possible. I'm
just wondering if there's software designed to do it.

-Brendan Long