Build your own Dial-up ISP with a Raspberry Pi

bigbuppo

Don't need to do that. I use a USR Total Control chassis as a white noise generator.

kotaKat

I feel like it would have been more fun to build your own line simulator with a 9 volt battery and some old phone line and just skip the dialtone altogether for a little magic... the $120 black-box telco simulator takes a lot of the fun out. But then again, based on Pi pricing today, the $120 telco simulator goes nicely with a $300 Pi 5.

alnwlsn

If you ever want more phone lines than that, you can pick up an old Cisco VG-224 from Ebay for less than half the price of that line simulator, and you get 24 lines. There is a configuration that will let you use it as a standalone unit where all the lines can call each other with custom phone numbers (here's some notes [1]). The main catch is that they have a 50-pin Centronics style connector on them which you will have to break out somehow to your RJ11s. Also, they are big (1U rack) and have fans. I've got a few of these and have been meaning to set them up with a bunch of modems and a bunch of computers, but haven't gotten to it yet. Modems do seem to work in the limited testing I've done. They do (as expected) work great with telephones, including pulse dialing. [1] https://alnwlsn.com/z/pots/cisco-vg224.html

aimadetools

I'd be curious if anyone has actually used a setup like this as a fallback for when their fiber goes down. The latency would be brutal, but a few kbps beats no bps

elevation

What I would love to have is a few compact dialup-to-wifi bridges so I could wifi-ize 30 year old hardware. Would be neat to read email with an old POP client, or chat over the original AIM software (perhaps patched to use a server on the LAN)

iberator

Nice, but slip and plip is more tun

m3rcury

I had a talk about building your own dial-up ISP in FOSDEM 2026, not the best but it remarks some points and configuration tips for especially running on VoIP. Thanks for keeping dial-up alive! https://fosdem.org/2026/schedule/event/UJKT3L-dial-up-howto/

eek2121

Semi-related note:I learned this morning that there are companies that offer in-home (non-cellular) phone service via wifi/the internet. Think: classic cordless phone, however the base station connects via wifi. Some of those companies offer free unlimited service as well...and the one I was looking at has a companion app for iOS/Android that allows you to make calls from via home number from anywhere as long as you have an internet connection. I'm assuming these numbers are flagged as VOIP (which limits their use as a lot of apps/sites/companies hate VOIP numbers), however the discover is interesting. I thought home phones were dead and buried.