[intercomincomingcall]
                exten => 1,1,Playback(attentionthephoneisringing)
                exten => s,1,Answer
                exten => s,n,SIPAddHeader(Alert-Info: Auto Answer)
                exten => s,n,Page(SIP/109&SIP/101&SIP/104&SIP/111&SIP/124&SIP/125)
                exten => s,n,Hangup