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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.

@Famicoman @ajroach42 @djsundog

in UK British Telecom would provide multiple circuits for "main + aux" eg you would have 10 pairs terminated on number 01632 960023 and they would be known as 01632 960023/1, 01632 960023/2 etc (we still have this arrangement for 2 analogue circuits at my office).

By late 90s these were often provided over ISDN E1 circuits and the modems could handle either normal PSTN or ISDN connections (including ISDN over GSM) >>

@Famicoman @ajroach42 @djsundog

BT *really* struggled to keep up with demand in some areas from the mid-late 90s and ended up giving away whole racks of equipment to ISPs as compensation for the delay in providing the circuits they had ordered...

@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

portmasters.com/

@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)

@Famicoman@mastodon.sdf.org if you're interested in a test call from a voip.ms 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.

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