This attribute is an extension of the Closed User Group (CUG)
facility, as follows:
This attribute, if set to a value of allowed indicates that outgoing
calls (from the DTE to the network) to the open (non-CUG) part of
the network are permitted. It also permits outgoing calls to DTE's
that have Incoming Access capabilities. If set to a value of
disallowed, then such calls cannot be made using this Dna - such
calls will be cleared by the local DCE.
This attribute corresponds to the ITU-T 'Closed User Group with
Outgoing Access' feature for Dna's in that outgoing access is
granted if this attribute is set to a value of allowed.