When dialing a Local Channel you are dialing within Asterisk into the Asterisk dialplan.
I was meaning somthing like this mabye, where 447589975480 is the caller ID on the outbound call, so you can replace it. NOTE THIS IS NOT AN STEP BY STEP GUIDE, just an example in order you get the logic of what I mean
asterisk -x âoriginate Local/423874671@myoutbound extension 20018090850@DialplanContextâ
[myoutbound]
exten=>_x.,1,verbose( calling to ${EXTEN})
same=>n,Set(CALLERID(num)=447589975480)
same=>n,Dial(SIP/${EXTEN}@istanbul,25)