[asterisk-dev] capture the time before Answer of call in dialplan

[Muteesa Fred]

Hello Everyone,

I apologise this might look like a user mailing list question but it's more
of a developers question. I think this is the only forum that can help me.

I have spent a week trying to achieve this. I realize I might have to write
a C or PERL extension to achieve it but I don't know where to start. Or
might need to rebuild the dial funtion.
Objective:
I want to dial a number in asterisk via a sip-trunk, and when the other
party answers the call, I want to test if the call was answered before 5
seconds, or after 5 seconds.
If it was answered in less than 5 seconds I want to cancel the call,
otherwise the call should continue.

Your guidance will highly be appreciated. 

Regards,
Fred Muteesa