This attribute specifies the type of ISDN messages that are to be
traced.
Description of bits:
alerting(0)
callProceeding(1)
connectionlessFacility(2)
congestionControl(3)
connect(4)
connectAcknowledge(5)
disconnect(6)
facility(7)
facilityAcknowledge(8)
facilityReject(9)
information(10)
notify(11)
progress(12)
register(13)
releaseComp(14)
release(15)
restart(16)
restartAcknowledge(17)
service(18)
serviceAcknowledge(19)
setup(20)
setupAcknowledge(21)
status(22)
statusEnquiry(23)
userInformation(24)
all(25)