Chapter 10 Install and System Administration for FortiOS 5.0 : Advanced concepts : Modem : Modem interface routing
  
Modem interface routing
The modem interface can be used in FortiOS as a dedicated interface. Once enabled and configured, you can use it in security policies and define static and dynamic routing. Within the CLI commands for the modem, you can configure the distance and priority of routes involving the modem interface. The CLI commands are:
config sysetm modem
set distance <route_distance>
set priority <priority_value>
end
For more information on the routing configuration in the CLI, see the CLI Reference. For more information on routing and configuring routing, see the Advanced Routing Guide.
See Also
Modem
Modes
Additional modem configuration
USB modem port