Can Twilio detect if a call to a Google Voice number gets forwarded to voicemail or an actual person?

I have an app that creates outbound calls to set up simple conferences.

I am having difficulty dealing with dialing out to Google Voice numbers as I use IfMachine to be able to determine if the call goes to voicemail for one or more participants so that I can "fail" the conference call attempt.

Here's the issue that I am having...

Google Voice answers the call attempt and asks you to say your name before forwarding your call onto the configured endpoint for that user.

I can use IfMachine to detect this and I can automate this portion and get Google Voice to forward the call, but then I can no longer detect if the call ultimately goes to voicemail or if an actual person picks up on the other end.

any ideas?

Solution

Twilio Evangelist here,

I think given that there are 2 points you need machine detection, you may want to use a <Gather> as secondary call screening before connecting the person to a conference.

When you make the outbound call to a number, you're using IfMachine to find out if you get to Google Voice. So that's great. But because you're passed that hurdle, it won't be triggered again.

What you could do is to use call screening, to manually detect a human with some TwiML like this:

<Response>
  <Gather numDigits="1" timeout="15" action="/some-conference-path">
    <Say>Press any key to be connected to the Something Something Conference</Say>
  </Gather>
</Response>

Then, if the call is answered by a human, they can press any key on their keypad and be redirect to the actual conference call, or if the Gather times out, you most likely got their voicemail.

You're basically combining automatic and manual machine detection as you need to do it twice at different points of the same call.

Hope this helps!