This attribute specifies whether fast select calls may be received.
This attribute, if set to a value of allowed indicates that incoming
fast select calls (from the network to the DTE) can be made to this
Dna. If set to a value of disallowed, then such calls cannot be made
to this Dna - such calls will be cleared by the local DCE.
This attribute corresponds to the ITU-T 'Fast Select Acceptance'
feature for Dnas in that incoming fast select calls are accepted if
this attribute is set to a value of allowed.
This attribute is ignored if the corresponding attribute, incCalls is
set to a value of disallowed.