The bing-bongs, screeches, and whiirings of a diai-up modem are long forgotten now. For good reason. Dial up was slow, and if you’re one of those unlucky people reading this and waiting for the animated gif above this paragraph to load, you have our condolences. But still, nostalgia. It bit [Doge Microsystems] hard, and now there’s a dial-up ISP on [Doge]’s desk. Why? For fun, probably, and if you’re going to retrocompute, you might as well go the whole way.
The setup for this astonishing feat of dial-up networking is an ISA modem inside a ‘lunchbox’ computer running what is probably Windows 98. The ‘homebrew POTS’ system is a SIP ATA (which is most certainly obsolete and out of stock, but this one will get you close), and a Raspberry Pi clone running Asterisk. There’s a serial modem and a USB to serial adapter involved, and a PPP daemon running on the Pi clone answers the incoming call, negotiates authentication, and does the NAT. It’s a networking geek’s dream.
As for what good this is, anyone who asks the question is missing the point entirely. Dial up is slow, horrible, and there’s a reason we don’t use it anymore. However, and there’s always a however, if you’re developing your own serial modem hardware for some weird project, I guess this setup would come in handy. If you’d like to test out a wooden modem, this is the setup for you. Yes, it’s ancient technology no one wants anymore, but that’s how you do it if you want.