Build Your Own Call Forwarding System Using Twilio Twimlets

June 28, 2011
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In this how to, we show you how to build your own call forwarding system by using Twimlets to implement a call transferring functionality where you can give out one phone number (your Twilio number), so that when someone dials that number, Twilio will ring multiple phones and connect the call to the first person to pick-up and accept the call. In case no one picks up, the call goes to voicemail.

We do this by using Twimlets, small web applications that implement voice functionality. Since Twimlets are stateless and all the required data is stored in the URL parameters, you won’t need to host this anywhere. All you need to start is a Twilio account, an email address to send the voicemails to and about 3 minutes to spare. Check out the instructional screencast and step by step guide to building this:

  1. Head over to the Simulring Twimlets page. The Simulring Twimlet will dial 2 or more (up to 5) phone numbers simultaneously, and the first person to answer is connected to the caller. If nobody answers, then the call is optionally forwarded to another URL (which can be another Twimlet).
  2. Enter up to 5 Phone numbers that you want to ring into the generator. Also enter a message that you want to play to the person who accepts the call. It should prompt them to press any key to accept the call. You can also paste the URL to an audio file that you want played instead. There is a default message, so you can skip this if you want to.
  3. For the FailURL, we are going to generate a Voicemail Twimlet. Click on the Generate button and select Voicemail Twimlet. Enter the email you want the voicemails sent to, a message to be read to the caller (or a URL to an audio file to be played) and select whether you want the voicemails transcribed. Click Ok.
  4. Copy the Resulting URL and paste it as the Voice URL for your Twilio Phone number inside your Twilio account.

And that’s it! You now have your very own call forwarding system powered by Twilio.