ADTRAN ISU 512e Manual page 118

Appendix B. Status Buffer Messages
Dump<1,2,3,4,6,7,8>
An incoming call on either the first or second channel was discarded
by the ISU. The calling number is displayed if available.
ExpISDN Active
Expert ISDN is currently in the process of determining the line's ISDN
format.
ExpISDN Failed
ExpertISDN has failed trying to determine the ISDN line's SPID for-
mat. This can occur if the telephone company is not using standard
SPID formats.
ExpISDN Passed
Expert ISDN has finished and has determined the ISDN line's SPID
format.
ExpISDN Retry
Expert ISDN is attempting another SPID format.
ExpertISDN Stop
The ExpertISDN process was stopped by the user.
FACILITY_NOT_IMP
The network does not support the requested supplementary service.
FACILITY_REJECTED
A facility requested by the user cannot be provided by the network.
B-6 ISU 512e User Manual 61203086L1-1