Originate a call with Asterisk - without the originating extension ringing

Question

I have a completely standard installation of Trixbox with 2 SIP extensions set up on it.

Both extensions are Snom 370 SIP phones.

I can originate a call from

Answer 1

I ended up creating a couple of new contexts in extensions.conf

[clickoutcontext]
exten => _X.,1,NoOp("Click In Context")
exten => _X.,n,SIPAddHeader(Call-Info: \;answer-after=0)
exten => _X.,n,Dial(Sip/${EXTEN})

[clickincontext]
exten => _X.,1,NoOp("Click Out Context")
exten => _X.,n,SIPRemoveHeader(Call-Info)
exten => _X.,n,Dial(Sip/${EXTEN})

And then using an AMI action to make the call:

ACTION: Originate
Channel: Local/101@clickoutcontext
Exten: 102
Priority: 1
Timeout: 60000
Context: clickincontext

This sends a header to the Snom phone making the call to tell it to auto answer and then removes it before the call is placed to the second phone.