Confbridge and dialplan_exec

Dear all,

i have configured a dialplan with Confbridge.
If the person digits 9 (when in the conference), the system will execute the context addcaller:


exten => 10,1,Set(CHANNEL(language)=en)
exten => 10,2,NoOp(${CALLERID})
exten => 10,3,Read(CONFERENCE_NUMBER,custom/${LANGUAGE}/confbridge-user-confnumber,6,${READ_ATTEMPTS},20)
exten => 10,4,Playback(auth-thankyou)
exten => 10,5,Record(RECORDED_MESSAGE:wav)
exten => 10,6,Playback(auth-thankyou)
exten => 10,7,Read(CALL_NUMBER,custom/${LANGUAGE}/confbridge-user-invite-partecipant,20,${READ_ATTEMPTS},20)
exten => 10,8,Playback(auth-thankyou)
exten => 10,9,Playback(custom/${LANGUAGE}/confbridge-user-invite-partecipant-back)
exten => 10,10,Originate(${OUTBOUNDTRUNK}/${CALL_NUMBER},exten,conferences,${CONFERENCE_NUMBER},1)


exten => _X.,1,Set(CHANNEL(language)=en)
exten => _X.,n,Set(LANGUAGE=en)
exten => _X.,n,Playback(RECORDED_MESSAGE)
exten => _X.,n,Set(CONFBRIDGE(user,template)=default_user)
exten => _X.,n,Set(CONFBRIDGE(user,admin)=no)
exten => _X.,n,Set(CONFBRIDGE(user,announce_join_leave)=yes)
exten => _X.,n,ConfBridge(${JOINCONFERENCE},participant_menu)

Everything works properly, but when A invites B, B joins the conference. When B leave the conference, automatically also A hangup.

Why this happens?..i can’t understand…

Thanks and regards,

Sorry, i have done some more tests: when B leaves the conference for some seconds (about 10 seconds) there is a busy tone (or something similiar). Why?

I have done some other tests.
The problem is the same as when an extension calls an external number, when the called number closes the call, for some seconds the calller listens a “congestion/busy” tone.
Is it possible to avoid this?

Thanks and regards,