; External SIP callers
[from-sip-external]
;exten => _.,1,NoOp(Received incoming SIP connection from unknown peer to ${EXTEN})
;exten => _.,n,Goto(s,1)
exten => s,1,Answer()
exten => s,n,Playback(digits/1)
exten => s,n,Dial(SIP/101,20)
exten => s,n,Hangup()


When I put in the _. lines commented out above, external SIP calls come in.
When I comment them out, they fail.

Why might that be?