but with Asterisk

extensions.conf

[v1_poc]
exten => _X.,1,NoOp(v_poc)
exten => _X.,n,Set(GLOBAL(foo)=${CHANNEL})
exten => _x.,n,Answer
exten => _X.,n,wait(0.1)
exten => _X.,n,Originate(Local/s-dummy@v2_poc,exten,v2_poc,s,1)
exten => _X.,n,wait(1000)

exten => h,1,NoOp(hangup v1)

[v2_poc]
exten => s,1,Noop(v2_poc)
exten => s,n,answer
exten => s,n,wait(0.1)
exten => s,n,dial(SIP/123@SIPTrunk,120,gG(v3_poc,s,1))

exten => s-dummy,1,NoOp(s-dummy)
exten => s-dummy,n,answer
exten => s-dummy,n,wait(720)

exten => h,1,NoOp(hangup v2)

[v3_poc]
exten => s,1,Noop(v3_poc)
exten => s,n,answer
exten => s,n,wait(1)
exten => s,n,playback(hello)
exten => s,n,bridge(${foo})
exten => s,n,wait(600)

exten => h,1,Noop(Hangup)
exten => h,n,softhangup(${foo})