[asterisk-users] detecting ring

[Julian Lyndon-Smith]

We have a large number of numbers (!) that we need to clean from our 
database. I've been asked if we can do this automatically, by checking 
if the number is valid or not from asterisk.

what I don't want to do is to disturb the phone owners if the number is 
valid.

obviously I can catch all the bad numbers, out of order etc by checking 
the hangup code.

is there any way of intercepting the fact that the target number is 
about to ring, and hangup before that happens ?

Julian