This attribute specifies whether the charging information facility is
signalled in the call request packet. A value of default indicates the
use of the value from the chargingInformation attribute of the
X25Dte component. A value of notSpecified means the facility is
not signalled. A value of notRequested means the facility is
signalled but charging information is not requested (that is, the
charging info field of the facility is set Off). A value of requested
means the facility is signalled to explicitly request charging
information.