|  | 6.4 | Frame Relay Subinterfaces
| 6.4.1 | What are Frame Relay subinterfaces?
To enable the sending of complete routing updates in a Frame Relay network, you can configure the router with logically assigned interfaces called subinterfaces. Subinterfaces are logical subdivisions of a physical interface. In a subinterface configuration, each PVC can be configured as a point-to-point connection, which allows the subinterface to act as a dedicated line, as shown in Figure . Early implementation of Frame Relay required that a router (that is, a DTE device) have a WAN serial interface for every PVC, as shown in Figure By logically dividing a single physical WAN serial interface into multiple virtual subinterfaces, the overall cost of implementing a Frame Relay network can be reduced. As shown in Figure , a single router interface can service many remote locations through individual unique subinterfaces.