[Asterisk-Users] Get the Caller-ID without Answering

[George Burt]

I have an application that I want to be able to verify that the call coming
in on a PSTN 800 number is from an authorized caller.

I want to read the CallerId then terminate the call without answering it.

   exten => s,1,Wair(3)
   exten => s,2,NoOp(${CALLERID})
   exten => s,3,Hangup()

Any ideas would be appreciated.

George