While installing your NCC 2020, or after it has been placed into service, the Diagnostic routines allow you to troubleshoot or verify the T1 circuit and Verilink equipment. The front panel of the NCC 2020 has three LEDs which give a visual indication of alarm conditions.
Display elements on the Diagnostics Menu give current information about possible alarm conditions as well as offering command options which may be used to establish and terminate loopbacks and test patterns.
A typical way of using the Diagnostics Menu might involve the following steps:
Establish a loopback somewhere in the circuit path.
Start transmitting a test pattern.
Observe the test error counter to see if the test pattern is received as it was sent.
If no errors are observed, move the point of loopback further away to test more of the circuit path, or
If errors are observed, move the point of loopback closer to determine the source of the problem.
Stop the test pattern, drop all loopbacks, then:
Place the T1 circuit back into service if all tests passed, or
Contact the appropriate vendor if a problem was found.
In addition to offering the ability to put up and take down loopbacks and test patterns, the Diagnostics Menu also offers information about the current status of the DSX-1 equipment interface and DS-1 network interface.
The top half of the Diagnostics Menu includes a drawing made up of ASCII characters which represents the operation of the CSU. The equipment interface is shown on the left and the network interface is shown on the right. In the area to the left and right of the line drawing of a framer, status information is represented by words displayed in upper case characters.
Verilink NCC 2020 User Manual