[Asterisk-Dev] important feature missing?!

[Payam Shabanian]

one of the common features in PBX devices is the ability to set a time limit
on duration of calls (esp. outgoing, for each station) and usually a warning
beep is played few seconds before time runs out. as far as i could
understand it's possible to set a time limit on calls using something like:
exten => 2000,1,AbsoluteTimeout(20)
but that's only on *incoming* calls and even so, the call is disconnected
without any warning beeps or anything. so i was wondering, am i missing
something or is this feature really not availabe in asterisk?