Auto Answer on any ATA?

Is there a way to Auto Answer on an ATA, I know it can be done on VOIP phones but what about an ATA, I dont see the settings on Linksys or Grandstream, perhaps I am missing something.


I think you’re going to have to have the device you connect to the ATA do the auto answering. The ATA basically simulates a POTS line allowing you to connect a device made for POTS to be used in a VoIP system. What are you trying to accomplish by having an ATA autoanswer?


Connecting a Viking PA solution, there are different models but there is an inexpensive model which does everything so long as I handle the Auto Answering.

Those all in one PA systems with Ethernet are way too expensive (like 500.00 a piece)

So if there was a way to have the ATA adapter auto answer the incoming call that would be great

There are a couple of ways to go about this:

  1. Modify a Sip Phone (I’ve used an AASTRA 9112) to bring the speaker audio out through an 8 ohm to 600 ohm isolation transformer.
  2. Use a device such as the Viking RAD-1A to answer the ATA and send the audio o the PA.

I’ve used both with equal results, although I prefer modigying the SIP phone.


For step 1, I heard people can do this with a GXP-2000 as well is that correct?

In either case, can I take the audio cables and connect them directly to a Horn (like the Viking 25AE)?

I’m sure you can do the same thing with a GXP 2000. Haven’t tried it, but it should be easy to do. The transformer is a available at Radio Shack.

You won’t be able to connect directly to a speaker because the Audio Output isn’t great enough to drive it directly. You’ll need to connect it up to an amplifier that’s rated to drive the number of speakers you’ll need.


You can do this with a Grandstream BT100, and the thing is only 30 bucks or so. :slight_smile:

Just connect the output of the audio isolation transformer into your paging amp, and when you call the (configured to auto answer) extension, you will get a brief ringtone followed by an open circuit to page through. Pretty slick if I do say so myself.

So whats the Transformer for?

To prevent humming caused by a ground loop. It also provides “isolation” between the phone and PA system, so that static charges or other high voltages do not cause damage. You’ll also notice the two different impedances listed, so this is also acting like a balun. In short; a balun’s function is generally to achieve compatibility between systems.