If you spend a few days playing with modems it feels natural that you eventually create a dialup ISP.

@Famicoman That's the plan for me this weekend. How'd you go about it?

@ajroach42 I already have a landline through Verizon, which is technically VoIP through FIOS, and I hooked it up to that US Robotics modem which is then hooked up to the chunky Pentium 4 era box running Windows Server 2003 and a RAS service. The router you see sits between the server and my home network running Tomato and a VPN client so anyone who connects through dialup gets routed via VPN to Sweden for egress so they don't do weird stuff exposed directly to my residential ISP.

@ajroach42 No reason you shouldn't be able to do the same with any VoIP provider and an ATA in place of a landline, and you could easily use a Raspberry Pi or other Linux box as the server with minimal config. Even modems these days can be USB dongles.

@Famicoman Neat! I was playing with minimodem earlier today (I blame Gravis) and I'm probably going to do some kind of dialup project this weekend.

@ajroach42 Hah gravis also kick-started this little project. I wonder what effect he just had on modem prices

@Famicoman Neat!

I've never really thought about how multiple users would work in that context (I guess I could ask @djsundog how he ran his ISP back in the day) but now that I think about it, I imagine that companies just had something like a POTS load balancer?

@ajroach42 @djsundog In a simple setup I imagine you'd have a pool of modems and one line per modem. The server can listen on as many modems as you connect. I know that some SIP trunks can allow multiple calls in on one number and your PBX can handle multiple incoming calls and route them to local available modems in a round-robin.

@ajroach42 @Famicoman yep, basically - one B1 line with a rollover on the circuit to bounce incoming calls to the first of N other B1 lines coming in with (unlisted) numbers, each with a modem all connected back to a serial terminal server (in my case, a sparc 10) that provided slip/ppp to the remote clients

@ajroach42 @Famicoman the fancy ISPs got specialized equipment like the Livingston Portmaster to simplify the setup, but it was basically all of that in a box lol

@ajroach42 @Famicoman (knocked the wind out of me to realize a portmaster goes for less than a hundred bucks on ebay these days - they were many thousands of bucks when they were exciting lol)

@djsundog @Famicoman We were unloading some unused network equipment recently, and it Shocked me how little that's worth, compared to how much it *very recently* cost.

@ajroach42 @Famicoman it'd be an interesting exercise to see how far a startup could go without ever using any hardware newer than ten years old at the time of acquisition. I bet it'd be a lot farther than most of them would think, if they were building with an eye for low-spec tech.

@djsundog @ajroach42 @Famicoman I more or less do this for my home stuff by picking stuff up cheap on eBay. My biggest annoyance is power usage, but I guess honestly it's probably less of an environmental impact than producing a *new* server (plus RAM, etc.). Probably similarly for my actual costs even with the inflated power bill.

@aschmitz @ajroach42 @Famicoman that's always been my operating assumption as well (modulo my smol computer fleet) if you're interested in a test call from a line let me know :>
got V.34 speeds to a BBS at one point, that was impressive

@natalie Thanks! Did you end up giving it a call? I realized last night that I never enabled logging so I have no idea if it has been called aside from some first test calls by my friend.

Sign in to participate in the conversation
Mastodon @ SDF

"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko