This variable decides whether 'incoming access'
is allowed for a CUG user.
the 'incoming access' allows a CUG user to receive
calls from all other non-CUG users and also from those
other CUG user that allow 'outgoing access'.
When the value is set to notAllowed(1), the
'incoming access' is not allowed.
When the value is set to allowed(2), the 'incoming
access' is allowed.
When this entry is created, this variable has a
value of notAllowed(1).