Once you understand how frame relay works, the mechanics of configuration are not very difficult. There are some interesting concepts, such as subinterfaces, that may be new to you; we'll cover those in detail here.
Figure 22-10 shows a simple two-node frame-relay network. Router A is connected to Router B using frame relay over a T1. The port speed is 1.536 Mbps, the CIR is 512 Kbps, and the burst rate is 2X (1,024 Kbps).
Figure 22-10. Two-node frame-relay network
The first step in configuring frame relay is to configure frame-relay encapsulation.
There are two types of frame-relay encapsulation:
ietf. The default type is
cisco, which is configured with the
encapsulation frame-relay command:
interface Serial0/0 encapsulation frame-relay
ietf type is configured with the
encapsulation frame-relay ietf command.
ietf frame-relay encapsulation is usually used only when
connecting Cisco routers to non-Cisco devices.
Once you've configured frame-relay encapsulation, and the interface is up, you
should begin seeing LMI status messages. If the PVC has been provisioned, you can see it
show frame-relay PVC command:
sho frame pvcPVC Statistics for interface Serial0/0 (Frame Relay DTE) Active Inactive Deleted Static Local 0 0 0 0 Switched 0 0 0 0 Unused 0 1 0 0 DLCI = 102, DLCI USAGE = UNUSED, PVC STATUS = INACTIVE, ...