2 ; Voice over Frame Relay (Adtran style)
8 ; Lines for which we are the user termination. They accept incoming
23 ; Calls on 16 and 17 come from the outside world, so they get
24 ; a little bit special treatment
29 ; Next we have lines which we only accept calls on, and typically
30 ; do not send outgoing calls on (i.e. these are where we are the
31 ; network termination)