[HN Gopher] Making VoIP Calls with Antique Rotary Phones
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Making VoIP Calls with Antique Rotary Phones
Author : yabones
Score : 38 points
Date : 2021-01-12 14:17 UTC (8 hours ago)
(HTM) web link (nbailey.ca)
(TXT) w3m dump (nbailey.ca)
| [deleted]
| jdofaz wrote:
| Back when I still had a landline I used to "impress" people with
| my ability to call their cell phone using only the hook switch on
| my desk phone.
|
| I'm pretty sure I was made aware of this trick from the 1995
| Hackers movie, so there is at least one accurate thing in that
| movie.
| snickms wrote:
| Its a little trickier in New Zealand, where one pulse means '9'
| :)
|
| https://commons.wikimedia.org/wiki/File:New_Zealand_Rotary_T...
| lngtmelistener wrote:
| I did something similar to this, and ordered a converter from
| Australia called DialGizmo, that could handle the two types
| common here, and probably could be configured for a New
| Zealand phone as well. Was harder to find reasonable PoE
| powered SIP adapters. :)
| EvanAnderson wrote:
| I don't recall if it was in the book, but the 1986 "Manhunter"
| film (an adaptation Thomas Harris' "Red Dragon") featured
| Hannibal Lecter abusing a phone with no dialing mechanism by
| way of shorting the switchhook to dial an operator by flashing.
| It was a neat thing to know how to do.
| techsupporter wrote:
| > 1995 Hackers movie, so there is at least one accurate thing
| in that movie.
|
| Recording the sounds that were emitted by a payphone when
| inserting coins and then playing them back into a payphone
| handset to get free calls ("red boxing") was a thing that def--
| err, maybe worked hypothetically I do not know and definitely
| never tried this absolutely not no way...
| EvanAnderson wrote:
| Understanding the difference between in-band and out-of-band
| signaling is valuable. Pay phones and how a red box exploits
| in-band signaling has been an example I've used in teaching.
| I find it less difficult to relate than the MF signaling that
| blue boxes exploited.
| Scoundreller wrote:
| Yeah, last I remember it was UPS that they transferred my
| call and then I heard a couple tones and thought "ohhh, in-
| band signaling".
| baobrien wrote:
| For anybody else wanting to do this, you'd be better off picking
| up a Grandstream 80X ATA. It supports pulse dialing, pulse to
| tone conversion, 'high power' ringing, and decently modern TLS.
| If you're good with a soldering iron and have a 3.3v TTL serial
| cable, you can also pick up really cheap used Vonage HT802s and
| 'unlock' them.
| borepop wrote:
| It's interesting to me how frequently on HN I read about people
| using their formidable technical expertise to pursue projects
| with really impractical and anachronistic technology, whether
| it's this project, or retrofitting some really old laptop with
| scarcely any processing power, or whatever. I understand the
| impulse to reject practicality and not let "the market" or merely
| pragmatic considerations dictate one's creative/intellectual
| impulses. But there is also something perverse about devoting so
| much brainpower and energy to these kinds of niche projects,
| which seem almost like a sort of performance art or a thought
| experiment made real. I find it kind of appealing, but also kind
| of odd.
| jes5199 wrote:
| Every time I work on something anachronistic or artificially
| constrained, I learn more about the fundamentals of the cutting
| edge stuff.
|
| There's a way that the "default" perspective of the industry
| tends to emphasize certain skills and knowledge and de-
| emphasize others, but the world of useful skills is much
| broader than that, and things crop back up in unexpected ways.
| Maybe we'll never need to make calls with an antique phone, but
| there could totally be audio and telephonic applications on
| modern hardware where the average engineer would have no idea
| what to do, but someone who had worked on a "toy" project like
| this would be able to say "oh, this is just like an old
| [whatever]"
| quesera wrote:
| I've thought about this often. My conclusion is that ~all
| humans "waste" time in some manner or other -- and that this is
| natural, probably necessary, and good.
|
| The same argument can be made for sleep. And there might be a
| useful analogy there...
|
| Psychologically "sleeping" (i.e. directing your energies in
| not-obviously-productive pursuits) bends your brain in a way
| that a relentless focus on "useful" work does not. This is
| probably true of all entertainment.
|
| Objectively, the person who spends 500 hours getting a 6502
| emulator working in JavaScript and then blogging about it, has
| added more to the world than the person who spends those same
| hours streaming The Simpsons.
|
| ...and also more than those of us who spend 500 hours _reading_
| the blogs of people who made crazy useless things happen...
|
| But _maybe_ the personal value of the diversionary time spent
| has some sort of parity..?
| borepop wrote:
| It occurs to me to that sometimes "silly" projects can also
| lead to practical applications. Mainly I think I'm struck by
| how many techy people have the impulse to pursue these quirky
| projects, and how there is sort of a poetic spirit to it
| under the techy exterior. As you say, it's certainly a more
| interesting and creative use of time than sitting on the
| couch watching TV.
| Glawen wrote:
| I was hoping to see some soldering action, well... Anyhow how
| would i go to create a home and self hosted VoIP network with 2
| phones? Any leads?
| randomstring wrote:
| I've been trying to figure that out myself. Another post here
| recommended Grandstream products for connecting analog phones
| to VoIP. Looking at the user guide for the HT802 you can make
| direct calls between the extensions.
| http://www.grandstream.com/products/gateways-and-atas/analog...
|
| Unfortunately there system requires dialing "*701" or "*702"
| and dialing star on a true rotary phone isn't possible without
| some other system in place. Like this product from dialgizmo:
| https://www.dialgizmo.com/how_it_works.html Dialing two
| consecutive stars would still be annoying and slow.
|
| I've been wanting to wire up an in-house "intercom" system
| using old phones. I'm a little surprised there isn't a
| "telephone HAT" for the raspberry pi that will interface
| directly with an old phone. A HAT that could interpret the DTMF
| or pulse dialing and drive even the old fashioned mechanical
| ringers.
| lngtmelistener wrote:
| I was thinking that there should not be any huge technical
| problem with making an FXS interface for the raspberry pi,
| and I did find a USB adapter which I might have been tempted
| to to try, but it's a little expensive and only supported 0.7
| REN (ringer equivalency number) which might not be enough to
| power the mechanical ringer on an old phone. Further
| searching did turn up the OAKR2 HAT though (
| https://switchpi.com/oakr2-module-specifications/ ) and it
| looks like the schematics are on github.
| hereforphone wrote:
| If you're really interested in this kind of thing check out
| C*NET: ckts.info. Members have all sorts of old telephone
| equipment up and available.
| cat199 wrote:
| have thought about doing not-quite this with a western electric
| touch-tone capable beige deskphone - anyone have any feedback on
| good/simple VoIP providers/software for personal use (like 1-2
| phone numbers + self hosted PBX/voicemail, remote access over VPN
| from softphone app a plus)?
| tshtf wrote:
| Provider to recommend to your parents or grandparents:
| Callcentric
|
| Provider for hobbyists who need flexibility: voip.ms
|
| Provider for cheapest termination rates and flexibility: Anveo
| Direct (not the consumer product)
|
| Bria and Groundwire have good SIP softphones for mobile, but
| aren't free. Since multitasking on iOS is so limited, these
| apps can register on their own servers, then send push
| notifications on calls.
|
| 3CX or Asterisk are good choices for connecting to trunks. 3CX
| is much less flexible, can cost money, but is "easy".
| yabones wrote:
| The provider I use is https://voip.ms
|
| The UI takes _some getting used to_ but the service is cheap
| and works great. Similar to how I did it, you 'd need an ATA
| box to provide analog service to the phone, and it would talk
| to your provider over SIP/RTP.
|
| Another option would be a self-hosted PBX box. Asterisk [1] is
| the tried and true open-source option, but it does have some
| sharp edges. 3CX [2] is another option, but it's proprietary
| and has some limitations.
|
| Either way, you would need a provider to give you the 'SIP
| Trunk' (phone number etc). I think Twilio [3] is the best
| option for this, but I've been using a hosted service for a
| while so I don't have much recent experience with this and
| can't vouch for costs/functionality.
|
| ---
|
| [1] https://www.asterisk.org/
|
| [2] https://www.3cx.com/free-pbx-edition/
|
| [3] https://www.twilio.com/sip-trunking
| blacksmith_tb wrote:
| I ported a landline to Anveo[1] long ago, and used it to route
| calls to a gVoice number, which worked pretty well.
|
| 1: http://www.anveo.com/
| icedchai wrote:
| I switched my landline from Verizon to Anveo about 5 years
| back. They are pretty solid! I barely used my landline so I
| have the cheapest plan possible.
| tzs wrote:
| For those who don't know how to use a rotary dial phone, here is
| a 1940 educational movie by Bell Telephone they made to teach
| customers about this new technology [1].
|
| [1] https://www.youtube.com/watch?v=p45T7U5oi9Q
| ape4 wrote:
| Aren't call calls carried digitally now - ie VoIP.
|
| (fun project).
| Animats wrote:
| I have a commercial box which connects an analog phone to a
| Bluetooth connection. It even generates ring voltage. (88 volts,
| 20hz). In this video of our old steampunk telegraph office, the
| phone in the foreground is fully functional. It's tied to a cell
| phone and can be used to make and receive calls. It's not really
| an antique phone, though; it's a 1970s reproduction. Strangely,
| it came with the connector for Japanese phones, and I had to find
| the mating connector for that.
|
| We let kids try it. One 7 year old said, picking up the handset,
| "It's so heavy".
|
| At home, I have several analog phones tied to a VoIP box on
| Sonic. They use the old house phone wiring, which is no longer
| attached to the telco. Plugging the VoIP box into a phone outlet
| drives them.
|
| [1] https://vimeo.com/97062822
| EvanAnderson wrote:
| What's the Bluetooth box, if you don't mind me asking? I have a
| reconditioned Southern Bell payphone I purchased years ago to
| benefit their retiree organization. The device you're
| describing would lower the barrier to entry enough that I might
| actually do something (since I could use my existing cell
| service vs. provisioning VoIP service).
| Animats wrote:
| There are several interface boxes, such as Cell2Jack. Mine is
| packed up right now, so I don't have the brand info.
|
| Coin telephones have a slightly different interface. But if
| it's been "reconditioned", the coin control system was
| probably disabled and it just acts like a ordinary analog
| phone.
| EvanAnderson wrote:
| Thanks. I'll take a look around for one. Sadly they did
| remove or disable the coin handling circuitry so it's just
| a funny analog phone now. I really should try to crack it
| open and see what's inside.
| jes5199 wrote:
| This takes me back! In the 1980s, I lived in a small town, and my
| Dad learned that the phone company still offered "party line"
| service for cheap - you could share a piece of copper with
| everyone on your street. I guess for most of the 20th century
| there were social norms about how to ask to use a shared phone
| line, how to know if a call was for your house instead of for a
| neighbor's house, etc - but by 1980 or so, everybody had
| household-private lines. So my Dad's insight was that he could
| save some bucks by paying for party-line service and we'd be the
| only house using it, so it would be de-facto private. But the
| side effect was that, since it meant we were using antique
| hardware at the phone company, it didn't support touchtone
| dialing! So we kept some 1960s-era rotary phones around, and when
| we got new phones we had to find the little hidden "tone/pulse"
| backwards-compatibility switch on the handsets (and my geeky
| friends would come over, click the touchtones back on, try to use
| the phone and say "hey, your phone is broken!" dude, you broke
| it. Presaging a long career in tech support, I suppose)
|
| We had to switch to modern lines after we got a 1200 bps modem.
| Someone from the phone company called and said "you've connected
| an electronic device to the party line, that's not allowed,
| 'cause how would your neighbors let you know they need to use the
| line?" apparently the argument "we're the only house on this
| line!" was not convincing. So touchtones started working, and
| presumably Southern Bell got to retire the last party line
| hardware at the switching station.
|
| So I've long wanted to do some kind of hacking with a rotary
| phone! I've seen lots of DIY projects that use analog phones as
| audio inputs, but they almost never including dialing, so this is
| exciting to see! I've always assumed you'd have to build your own
| pulse-counting circuit, I had no idea there was a commercial
| option, that's kind of mind-blowing, but I suppose they were
| needed to support old hardware.
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