Hi galovic.
Place the following lines in /etc/asterisk/extensions_custom.conf and you 'll have Whisper & Listen mode. I am trying to work out why the Barge mode isn't working and I 'll let you know as soon as I face it.
[ext-local-custom]
;listen
exten => 222x.#,1,Macro(user-callerid,)
exten => 222x.#,n,Answer
exten => 222x.#,n,NoCDR
exten => 222x.#,n,Wait(1)
exten => 222x.#,n,ChanSpy(sip/${EXTEN:4},q)
exten => 222x.#,n,Hangup
;whisper
exten => 223x.#,1,Macro(user-callerid,)
exten => 223x.#,n,Answer
exten => 223x.#,n,NoCDR
exten => 223x.#,n,Wait(1)
exten => 223x.#,n,ChanSpy(sip/${EXTEN:4},qw)
exten => 223x.#,n,Hangup
;barge
exten => 224x.#,1,Macro(user-callerid,)
exten => 224x.#,n,Answer
exten => 224x.#,n,NoCDR
exten => 224x.#,n,Wait(1)
exten => 224x.#,n,ChanSpy(SIP/${EXTEN:4},q
exten => 224x.#,n,Hangup
