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CHAPTER 14: Viewing Status Information
C
URRENT
S
TATUS OF
D
IAL
B
ACKUP
M
ODE
This display line (see Figure 14-1) indicates the backup service status. Possible
messages include the following:
Answering Call
The CSU/DSU MS DBU detected an incoming-
call message and is initiating call-setup
procedure.
Call Disconnect
Call-disconnect message received from the
remote end.
Called Unit Busy
The unit called is currently busy and cannot be
connected (ISDN only).
Dialing
The unit is dialing the selected number.
Going to DBU
The CSU/DSU MS DBU is entering dial-backup
mode.
Idle
Messages are not being transmitted, but the
service is immediately available for use.
Incoming Call
Incoming-call messages being received.
In Dial Backup
The CSU/DSU MS DBU is currently in dial-
backup mode.
No RX Signal
Sealing current detected but no data signal
received from telco. Also indicates ISDN line is
inactive.
No wink from CO
Switched 56 provider encountered a service
problem (4-wire SW56 only).
Not Installed
No dial-backup option installed in the
CSU/DSU MS DBU.
OOS/OOF From Net
Out-of-service signal or out-of-frame condition
exists. The call cannot be completed because
the called terminal or the called terminal’s
access line is out of service or is faulty (4-wire
SW56 only).