I’ve tried to add intercom=true to SIP_URI_OPTIONS but it doesn’t get sent on INVITE.
Dialplan:
exten => _X.,1,Set(SIP_URI_OPTIONS=intercom=true)
exten => _X.,n,Dial(SIP/102)
And the INVITE line doesn’t contain the added parameter:
Asterisk v 1.8.3.2
Any idea how to get it to work?
Tnx in advance!
Try this:
exten => _X.,1,Set(__SIP_URI_OPTIONS=intercom=true)
exten => _X.,n,Dial(SIP/102)
Malcolm, tnx for your help!
It works 
If anybody else runs into similar, just google asterisk inheritance of channel variables.
Malcolm tnx again for your quick response.
You’re very welcome. 
The reasoning:
You need the dialed channel, not the calling channel, to inherit the variable’s settings.