Digicom COMSPHERE 3911 User Manual

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  Call Setup Branch
10-5
3910-A2-GN32-40
September 1998
Dial Standby/Return to Dial
When the modem is operating in Dial Backup mode (DialBckUp), Dial Standby and Return to
Dial allow the modem to switch back and forth between primary leased-line and primary
leased-line backup operation while still maintaining the backup connection (Figure 10-1).
Switching between backup and primary leased-line operation can be performed manually or
automatically. (Refer to Leased Line in Chapter 5, DCP Configuration, to enable the Automatic
Dial Backup configuration option.)
496-13081-01
MODEM
MODEM
LEASED-LINE
FAILURE
X
X
DIAL BACKUP LINE
DIAL
STANDBY
RETURN
TO DIAL
Figure 10-1. Dial Backup
Under normal backup conditions, when a problem occurs on the primary leased line, the modems
establish a connection over the backup network.
F1
Call Setup:
Dial Standby
F2
F3
When this occurs, Dial Standby appears on the LCD in the Call Setup menu branch. If you select
Dial Standby, the modem switches back to the primary leased line while still maintaining the
backup connection. As a result, Return_to_Dial appears on the LCD instead of Dial Standby.
F1
Call Setup:
Return_to_Dial
F2
F3
If the primary leased line is unacceptable, select Return_to_Dial which switches the modem
back to backup network operation (LCD displays Dial Standby). If, however, the primary leased
line is operating properly, select Disconnect from the Call Setup branch to drop the dial backup
connection. Also, if the primary leased-line operation is maintained uninterrupted for the amount
of time specified in the Dial Standby configuration option, the dial backup network disconnects.