Leased-Line Dial Backup; Dial Backup - ZyXEL Communications U-336R/RE User Manual

configuration. Be sure that one modem is set to originate mode and
the other to answer mode.
AT-Command Description
AT*M0
AT*M1

Leased-Line Dial Backup

When a leased-line connection fails, the following actions may be
taken by the modem:

Dial Backup

The dial backup option can be set by issuing an asynchronous AT
command from the terminal, or by using the RS-1612 LCD control
panel.
AT-Command Description
AT*B0
AT*B1-50
When operating over a leased line, modem will
handshake in originate mode. (Default)
When operating over a leased line, modem will
handshake in answer mode.
Reattempt to connect on the leased line indefinitely if the dial
backup option is disabled.
If the dial backup is enabled, the originating modem attempts to
dial a pre-stored telephone number to backup the connection;
the answering modem will reattempt to connect to the leased
line and monitor the dial-up line for rings. Incoming dial-backup
calls will be answered.
Leased-line dial backup disabled (Default).
When the leased-line cannot continue operation,
the originate mode modem will automatically
dial the number stored in the memory address
selected. The answer mode modem will monitor
the dial-up line for rings.
Leased Line Operation 37