[Asterisk-Dev] Answer Supervision for incoming calls in Asterisk

[Kevin P. Fleming]

Adam Goryachev wrote:

> However, when calling from my mobile phone (Optus Australia) to
> asterisk, and doing this, I didn't hear anything from the playback, just
> silence. Eventually, asterisk answers, and then I hear audio. (Even
> though it worked from landlines, and other mobiles). So, your 'warning'
> may not be enough for some people ??

That's correct; not every path through the PSTN allows for early audio 
delivery. Mobile phones frequently do not, and also frequently do not 
allow access to premium numbers anyway :-)