This attribute, if set to a value of allowed indicates that outgoing
fast select calls (from the DTE to the network) with an unrestricted
response can be made using this particular Dna. 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 is ignored if the corresponding attribute, outCalls is
set to a value of disallowed.