8.2 Configuring Frame Relay
8.2.3 show interface serial command
After you configure Frame Relay, you can verify that the connections are active by using different show commands. The show interface serial command displays information regarding the encapsulation, Layer 1, and Layer 2 status. It also displays information about the multicast DLCI, the DLCIs used on the Frame Relay-configured serial interface, and the LMI DLCI used for the local management interface, as displayed in the Example .

Local-Loop Identifier-Circuit Number
A typical Frame Relay WAN is composed of numerous sites that are connected to the central office via a local loop. The telco identifies these individual local loops with a circuit number, such as: 05QHDQ101545-080TCOM-002. Telco technicians typically leave a label on the channel service unit/data service unit (CSU/DSU) with the circuit number. When you call the telco for help with troubleshooting your Frame Relay WAN, you will be required to provide the circuit number.

To simplify the management of your WAN, use the description command at the interface level to record the circuit number:

Halifax(config)#interface serial 0
Halifax(config-if)#description 
Cicuit- 05QHDQ101545-080TCOM-002 
Halifax(config-if)#^z
Halifax#show interface serial 0
Serial 0 is up, line protocol is up Hardware is MCI Serial
Description 
Circuit-05QHDQ101545-080TCOM-002
Internet address is 150.136.190.203, subnet mask 255.255.255.0
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 uses, rely 255/255, load 1/255