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T1/E1 Digital Voice Port Adapter Installation and Configuration
OL-3592-02
Chapter 4 Configuring the PA-VXA, PA-VXB, and PA-VXC
Checking the Configuration
Cisco 7500 Series Routers:
Router# config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# controller t1 2/2/0
Router(config-controller)# loop remote esf line
This command causes the far end to loop its receive signal back to transmit.
E1 Loopback Examples
Specify loopback for an E1 controller using the loopback command. There are two main loopback
modes: diagnostic and local (line and payload). Specify the loopback format using the
loopback [diagnostic | local] command.
Note
To shut down the E1 controller, use the shutdown command at the controller prompt.
Examples of specific loopback modes for the E1 controller follow:
•
The syntax of the loopback diagnostic command is as follows:
loopback [diagnostic]
Set the first E1 into diagnostic loopback.
Cisco 7200 Series Routers:
Router# config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# controller E1 2/0
Router(config-controller)# loopback diagnostic
Cisco 7401ASR Routers:
Router# config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# controller E1 1/0
Router(config-controller)# loopback diagnostic
Cisco 7500 Series Routers:
Router# config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# controller E1 2/2/0
Router(config-controller)# loopback diagnostic
In the preceding examples, the loopback diagnostic command loops the outgoing transmit signal
back to the receive signal and sends an AIS out to the network.
•
The syntax of the loopback local command is as follows:
loopback [local {payload | line}]
Set the first E1 into local loopback.
Cisco 7200 Series Routers:
Router# config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# controller E1 2/0
Router(config-controller)# loopback local payload
