This bitmap describes the use of the facili-
ties data link, and is the sum of the capabili-
ties. Set any bits that are appropriate:
other(1),
ansi(2),
att(4),
none(8)
'other' indicates that a protocol other than
one following is used.
'ansi' refers to the FDL exchange
recommended by ANSI.
'att' refers to ESF FDL exchanges.
'none' indicates that the device does
not use the FDL.