Is there a way to get the caller's number before the call ends?

Question

linux

In order for AON to work on a PBX, you need to order a new board for the LDK-300.
But AON is needed here and now.
There was an idea to redirect calls to an asterisk, immediately direct the call to the desired number in extensions, and pull the caller's number from the logs - with a script, sending it to office computers with the Linux command notify-send.
The problem is that the number appears in the logs only after the call is completed.
How can you intercept and write to a file the date and number (or at least the number) of the caller, before the call was completed?

Answer 1

CALLERID (num) in dialplan