[asterisk-users] duration sec and billing sec in cdr

[Eric "ManxPower" Wieling]

Steve Jones wrote:
> This is interesting to me..  I'm a newbie, so please forgive a dumb
> question, but what use is it to play a message if you don't pick up the
> phone first??  Who's hearing it?

Many types of connections allow you to do "early audio" or "on hook 
audio".  A perfect example of this is when you call a disconnected 
number, you get the telco audio message, but don't get billed for the 
call....because the telco never answered the line.