The persistence of the WAN interface in the system. Demand(2) circuits are pre-configured but are opened only when there is some data to be sent (these interfaces are administratively UP, but operationally DORMANT and they are made UP dynamically whenever there is any data to be sent over the interface). The demand circuit configuration continues to persist in the system. Alll other WAN interface which do not fall under the above categories are to be configured as other(1) which is the default value.