Using Asterisk to Stop Robocallers

Accepted Session
Short Form
Scheduled: Thursday, June 25, 2015 from 1:30 – 2:15pm in B304


Robocallers are very annoying. Even when the Do Not Call list works, it doesn't cover all robo callers. This talk is about combining Asterisk (an open source PBX) running on a BeagleBone and some inexpensive hardware to really stop these annoying callers.


I got really tired of getting automated calls on my home phone (yes, I’m old). Although being on the Do Not Call registry helps, it doesn’t stop all potential callers. So, I decided to do something about it. I used a $50 device that turns analog phone lines into digital lines and the Asterisk software to make callers prove that they are human before the call is allowed to ring the house phones. In effect, I have a captcha for my home phone.

  • Setting up a Beaglebone with Asterisk
  • Setting up an ATA for analog phone lines
  • Connecting and setting up an ATA
  • Asterisk dialplans
  • Setting up the captcha logic


asterisk, hardware, telephony, beaglebone

Speaking experience

I have spoken at Open Source Bridge in 2013 and a prior year as well as ApacheCon.

This is a new talk that I haven't given before.