Chapter 5 - Monitoring and Testing the Campus System

Performing Loopback Testing

Loopbacks provide testing for the HDSL data communication path between the Campus unit, the remote unit, and the remote host equipment. Loopback tests can be run only when one end of the HDSL connection (either the local or the remote) is a Campus-REX2 or Campus-REX (both ends cannot be Campus-REX2 or Campus-REX).

The following section describes how to set up, run, and terminate loopback tests.

Configuring Loopbacks

If both the local and remote Campus units have a Campus-REX2 RS Interface Card, no loopbacks are supported between the two units.

The Campus-REX2 supports the following types of loopbacks between a Campus-REX2 and another Campus unit that contains a synchronous interface card such as V.35 or DSX-1:

The Remote to Remote loopback tests the remote data port.

The Local to Remote loopback tests the remote data port, the entire data path inside the remote Campus unit, the HDSL line, the HDSL transceivers of both units, and most of the internal data path inside the local unit. This loopback does not test the local data port drivers and receivers.

Once a loopback condition has been initiated, it remains in effect until it is cleared. You may also set a loopback timeout to clear the loopback automatically after a set period of time has elapsed.

Campus-REX2 RS Interface Card User Manual

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