[Asterisk-Users] No 'ringing' sound to outside callers

[Matt Lawson]

Most of the time, when someone calls in from the outside on a POTS line, 
and possibly over IAX as well,  they don't hear any ringing sound while 
the internal SIP phones ring.  If you call from an inside SIP phone, 
even forcing it into the incoming context, you hear the ringing.

The outside calls can answer and talk fine; just no ring indication.  Is 
there a setting that controls this?  Thanks.