
214 Chapter 6 • Enabling Dial-on-Demand Routing (DDR)
Physical Interface
The physical interface is the interface that will physically connect and
establish a “line up, protocol up” status. As mentioned in Chapter 5, this
can be an ISDN BRI or PRI interface, an asynchronous serial interface or a
synchronous serial interface. As with the rotary group, only a limited
amount of configuration information needs to be put on the physical inter-
face.
Dialer List
The dialer list is what identifies interesting traffic, which causes the router
to initiate dialing and keep the interface in an “up, up” status. For a
detailed overview of dialer lists, see Chapter 5. ...