Specifications

89
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).