ADTRAN 1200051L6 - Manual (Page 122)

Appendix C: Status Buffer Messages
108 ISU 2x64 Dual Port ISDN Service Unit User Manual 61200051L1-1D
TXINIT expired
Bonding timer TXINIT expired, called non-BONDING equipment
or B channel not error free.
UNASSIGNED_NUMBER
The phone number dialed does not exist.
Unknown AT & cmd
User issued an unknown AT command.
UNSPECIFIED_CAUSE
Received a cause message from the network that is not under-
stood.
Unsupported baud
The ISU 2x64 does not support the negotiated baud rate.
USER_BUSY
The dialed number is busy.
V120 timeout
The far end unit is not set up for V.120 or B channel not error free.
V120 connected
The V.120 rate adaptation successfully connected to the far-end
unit.
WRONG_MESSAGE
Call control error.
WRONG_MSG_FOR_STATE
Call control error.