Hi All, I don't know it's possible or not. I want to do run time codec selection by asterisk. I have an account in sip.conf and I have active only g729 on it [2209] ....... disallow=all allow=g729 ....... When try to dial that number when I want to use codec GSM. Is this possbile to change code after making call to exten ? *extensions.conf information is below:-* exten => _2xxx,1,Answer() same => n,GotoIf($["${EXTEN}" = "2209"]?setchannel:gowithoutit) same => n(setchannel),Set(foo=${CHANNEL(audioreadformat)}) ; same => n,Set(CHANNEL(audioreadformat)=gsm) it's not update anything might be readonly property, that's y commented. same => n,Set(_SIP_CODEC=gsm) same => n,Set(_SIP_CODEC_OUTBOUND=gsm) ; same => n,Set(foo=${CHANNEL(audionativeformat)}) ; same => n,Set(foo=${CHANNEL(audiowriteformat)}) same => n(gowithoutit),Dial(SIP/${EXTEN},60) same => n,GotoIf($["${EXTEN}" = "2209"]?voicemail) same => n(voicemail),VoiceMail(2209 at hyd,u) same => n,Hangup() -- Thanks and regards Virendra Bhati +91-8885268942 Software Engineer E-mail-: virbhati at gmail.com Skype id:- virbhati2 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20120227/06c5e5d6/attachment.htm>