Rotary Phone POTS VoIP Line


When ditching land lines many moons ago, i created the Phone System Using VOIP and Bluetooth page to make land lines worth with your cell phone via bluetooth.

Now let's do something more simple - make a Rotary POTS phone (or I suppose any phone, but where's the fun in that) function in the year 2020. This is honestly so simple that it barely requires documentation, all of the work is done by an ATA (Analogue Telephone Adapter) device that supports pulse dialing - Grandstream HT801 in my case. Some nerdier folks than I also compiled a list of other compatible ATAs here.



                   | Series of tubes
             [Home Router]
                   | Ethernet
             [Grandsteream HT801]
                   | Existing House Phone Wiring
             [Rotary Phone(s)]


This cost me ~$50 for hardware and about $2/month for the phone service. This of course assumes you have Internet as well.

  • Rotary Phone - I came came across a pair at a garage sale for $20. I bought them simply to cover the phone plate on the wall as decor, but then decided that hey, why not make it work too.
  • Grandstream HT801 ATA - ~$30 or so from Amazon. Do NOT get a Vonage version or it will be locked. You can find Vonage branded HT802 (2 phone line) on Ebay all day for $10, but unless you want to do some soldering, don't bother. Grandstream also make a lot of these devices, most of them support pulse dialing. Other models that would work -HT802, HT702, HT502. I actually had a HT502 already from my previous land line experimenting but it no longer produces a dialtone.
  • Internet VOIP provider. I use as it's really cheap. You pay per minute used, and if you want a DID (actual dial in number) it's $1.95/month. So my bill is about $2/month. If you want 911, it's another $2/month.


  • Take a standard phone cord, cut it in half. Strip the wires back, and connect the red and green to red and green of your house's demarc. My 80s house has screw terminals and whatnot and was pretty simple.
  • Configure your ATA. Callcentric has solid docs to make it work with them. Create an account on their website, then just follow their instructions. The screenshot is overwhelming, just skip to the part that has the table of settings/values.
    • I did make one tweak here, which was to the dialplan. I wanted it to work like traditional phone lines where you don't have to dial your area code if local. IF you use their default, you'd have to always dial the full 10 digit code. So, instead of the default {[x*]+}, I used {[49]11|<=1608>[2-9]xxxxxx|1[2-9]xxxxxxxxx|011[2-9]xx.|*x+}, which means
      • [49]11 - allow you to dial 411 or 911 normally
      • <=1608>[2-9]xxxxxx - prepend 1608 when the number starts with 2 through 9 and has six more digits. Replace this with your local area code.
      • 1[2-9]xxxxxxxxx - Numbers starting with 1 then 2 through 9 and eight more digits dial normally
      • 011[2-9]xx. - Numbers starting with 011 then 2 through 9 and any further length dial normally. This is for international calls.
      • *x+ - I believe this is just a wildcard for anything else

  • Test. If you just have the ATA connected and configured, its web interface should show if it is registered to your VoiP provider, as well as indicate when ringing. I'd connect a phone directly to it before your house wiring.
  • Connect output of the ATA to your phone wiring at your demarc area, which is perhaps in your basement. Disconnect any existing wires coming from the phone company first.
  • Connect your phone to existing jacks.
  • Call your grandmother and reminisce.