HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual page 142

Configuring Backup WAN Connections
Configuring a Persistent Backup Connection
N o t e
3-62
Table 3-9. Backup Call Modes
Command Syntax
backup call-mode answer
backup call-mode answer-
always
backup call-mode originate If the primary connection fails, the backup interface will place
backup call-mode
originate-answer
backup call-mode
originate-answer-always
When a connection's backup call mode is set to either answer-always or
originate-answer-always, the ProCurve Secure Router will force a func-
tional primary connection down in favor of the backup connection. You should
use this option for sites that are not directly connected.
For example, in Figure 3-18 Router A acts as a hub in a Frame Relay network.
Router B's T1 connection fails, and it places a call to Router A. Router A's T1
lines are still good, and its PVC to the Frame Relay provider may still be up.
If the subinterface is only set to answer, the router will not answer the call,
and the connection to Router B will be lost. However, if the Frame Relay 1.102
subinterface is set to back up call mode answer-always, the backup interface
will force PVC 1.102 down and bring up the backup connection.
Description
If the primary connection fails, the backup interface will
answer backup calls but not place them.
The backup interface will always answer backup calls, even
when the primary connection is up.
a backup call; it will not answer a call.
If the primary connection fails, the backup interface will place
or answer a call. It refuses calls when the primary connection
is up.
If the primary connection fails, the backup interface will place
or answer a call. It will also answer backup calls when the
primary connection is still up.