Anyone from MIT's Tau Epsilon Phi around to confirm/deny that TEPaphone is still running? In the late 1990s/early 2000s, a friend of mine (a brother in TEP) told me about their PBX hand-wired from mechanical relays and stepping switches as a hobby project by one of their brothers a decade or two earlier. Apparently its creator was far more interested in the project than in his coursework, to disastrous effect.
If I recall correctly, every-other class, they needed to decide which brother was going to be the designated recipient of the handed-down arcane design and maintenance knowledge. I believe the title of office was Phone Master, and just like Sith Lords, there were always 2: master and apprentice.
On the plus side, it had a photo sensor sitting over the washer and dryer display lights, so dialling the extension for the washer or dryer would give a busy tone if in use, and a ring tone otherwise.
It still shows up in the interactive text adventure tEp house tour[1] (ask irving about Tep-O-Phone, or find it in the basement hallway) but, bad news:
> Built from relays that fell out of a Bell telephone truck by Fred Fenning while he was failing his telephony class, Tep-o-phone was a state-of-the-art telephone switching system that let the outside world dial individual rooms, switching tEp's six external lines. It also let people call the laundry room (Mr. Washer and Ms. Dryers) to see if there were free machines. Sadly, Tep-o-phone has since fallen into disrepair with the now-widespread use of cell phones, but every once in a while it tries to connect a call for old time's sake.
Tangentially related: if you're fascinated about how all of this vintage equipment used to work, and if you find yourself near downtown Seattle on a sunday with an hour or two to spare, I strongly encourage a visit to: https://www.telcomhistory.org/connections-museum-seattle/
It's an incredibly rare opportunity to see geek geezer volunteers keep this central office telephone switching equipment up and running, and they'll proudly show you how it all works. A combination of aging techs and students constantly maintain equipment ranging from crossbar switches to an ESS.
It's a labor of love, and you'll want to leave something in the tip jar just to say thanks.
I can also highly recommend the Connections Museum.
As someone who has spent his career in networking and automation, it was fascinating to see the ingenious electromechanical ways people found to automate early circuit switching. In addition to the working step-machine, panel switch, and crossbar switches, they have a collection of teletypes and other miscellaneous curiosities. The power systems necessary to run the CO and provide dial tone to the area were also quite fascinating.
As an example, one of the small curiosities that particularly fascinated me was a device that read out the current time. This automated a minor facet of what human operators could do that the electromechanical switching systems could not: telling the current time.
I've watched many of the videos on their YouTube channel and have been blown away by all the cool stuff in that museum, and the talented people that keep it going!
It's high on my list of things to see in the US when I next get a chance to spend some time there (which could be several years away so I hope it keeps going strong).
Reading this reminded me of my earliest "IT Guy" days in the mid-late nineties when nearly every office had a PBX no matter the size. I just remember replacing burned out line cards, and the system held like 20 cards of 5 lines a piece. They'd burn out for no reason and you had to replace them randomly on a Friday after you were half way home and thinking about the cocktail that needed mixing.
> Sangoma Meet is based on WebRTC, which provides video conferencing and is supported by most of the major web browsers today.
> Our software stack is built upon several open source tools, including Jitsi Meet, FreeSWITCH™, HAProxy, Prometheus, Grafana, collectd, and other tools used for provisioning, deploying and managing the service.
> Mobile Soft Client: Take your company phone extension with you anywhere using a mobile soft client. Forward calls from the office, receive voicemails, start a video meeting, and much more! When you call your customers or clients through the Sangoma Talk app, they will see your office phone number, which allows you to maintain your personal device privacy. Available for iOS & Android devices.
GVoice (originally GrandCentral) can't do voice or video call transfer to the mobile soft client app, FWIU
The UHF Bridge is interesting… I wonder if that’s a thing Norway lets you do? I’m pretty sure in the US you need a ham license to patch phone over radio like that.
It may well be similar to the situation in the UK, where - while it is not really within the terms of a licence for (for example) unlicensed 446MHz radios, no-one is going to do anything about it.
In the US the FCC will go after you for running half a watt over your power limit. In the UK, Ofcom literally cannot be paid to take an interest on what happens on amateur or ISM bands, and will only get involved if you're making a nuisance of yourself on commercially licensed frequencies.
In the UK, I think both parties to the call would need licences - and they’d need to be using callsigns - that’s assuming they’re using an amateur band.
Ah, interesting. I saw "analog" and was expecting something more like controlling crosspoint switch ICs[1] to cross connect lots of handsets in arbitrary ways. But this is analog multiplexing, digital routing, etc.
I wonder if his system works with Fax/modem connections. He uses ADCs, so I guess not? That would be a hard requirement for me if I ever built something similar
It's hard to say for sure without seeing more technical detail, but I would expect that a modem connection would "just work" without any further changes.
The point of a modem is to translate data into an analog signal that can be decoded after going through a lossy transmission line, subject to bandwidth constraints and noise. The ADC introduces quantization noise, which affects the signal-to-noise ratio, but the same thing happens in a "real" phone line that goes over a digital trunk, and modems are designed to tolerate it.
Also, even if the connection quality is especially poor, modems are designed to perform a "line probing" algorithm, in which both ends of the connection will fall back to the slowest connection speed that can be reliably established.
In this case only the control plane is digital, the signal plane stays fully analog from end-to-end. So it really should not have any trouble with fax/modem signals.
If I recall correctly, every-other class, they needed to decide which brother was going to be the designated recipient of the handed-down arcane design and maintenance knowledge. I believe the title of office was Phone Master, and just like Sith Lords, there were always 2: master and apprentice.
On the plus side, it had a photo sensor sitting over the washer and dryer display lights, so dialling the extension for the washer or dryer would give a busy tone if in use, and a ring tone otherwise.