Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I would like to set up a phone service that provides automated information to users who dial a number on an ordinary telephone - think "Dial-A-Joke" or something similar ("press 1 for this, press 2 for that, ..." and then the system reads off whatever you chose). This is often called an Interactive Voice Response (IVR) service. The service should be installed on a generic server from a hosting provider with no special hardware - an Amazon EC2 instance, for example.

It seems that twilio would be perfect, because it handles all the telephony and your server drives it by responding to ordinary HTTP messages. Unfortunately, it isn't available yet in my country (Great Britain).

Can I set up what I want using Asterisk? I can find tutorials on setting up Asterisk on hosted servers (just by searching google for "asterisk ec2") but none of them explain how you go on to pick up an ordinary phone and dial the Asterisk instance you just set up, or how you configure it to respond with given messages.

Just to be clear, I'm aware that hooking up to the plain old telephone service will cost something. I would like the option to have my users pay a small per-minute fee to cover this, or to take up that cost myself (not sure which model I'll use yet).

share|improve this question
up vote 1 down vote accepted

Yes, Asterisk will do this. What you need to do is find a VoIP provider that will give you a PSTN ("plain old telephone service") number and then forward the call to your Asterisk server, which then handles all the tricky bits.

There are plenty of VoIP providers around that will do what you want; not being in the UK I couldn't say who might be good or useful to you in your area. Make sure you get someone who can provide you with "local" numbers in the area you've chosen for your customer base, and is fairly close to where you'll be running the Asterisk server (Internet latency can be a real killer for this sort of thing). Some VoIP providers will even be able to provide you with the premium number to cover your costs, if you go that way, otherwise a "regular" telephone company can handle that part of it then forward to your VoIP provider's number.

share|improve this answer
Very helpful, thanks! Two follow-on queries: 1. I've searched for VOIP providers in the UK and there are several, including Vonage, but they all seem focussed on retail usage (making and receiving calls in your home or office). What phrases might I use to search for a provider that can do this? (I tried "pstn forward voip" and variations, with not much luck.) 2. I've never used Asterisk before; do you know any tutorials that can help me set up the logic on my server to route users through the menus and read out the results they get? – Douglas Squirrel Aug 1 '09 at 14:30
Most of the "receive calls in your home or office" outfits can do what you need -- there's no difference, technically, between forwarding a call from a PSTN number to a business VoIP PBX and forwarding from the PSTN to an IVR server. What you want isn't as common a service, so it probably won't be advertised as heavily, so you'll need to ask some providers about it specifically. As far as tutorials go, I don't know anything specific, but anything dealing with IVRs should get you started well enough. – womble Aug 1 '09 at 14:38
Thanks! "IVR" appears to be the magic word. Using it, I found a relevant stackoverflow question - - plus info on Asterisk Gateway Interface ( and Asterisk-Java for AGI from Java ( – Douglas Squirrel Aug 1 '09 at 18:24

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.