COMMUNICATIONS WIRING NOISE LEVEL MONITOR AND ALARM INDICATOR

In an apparatus and method of testing the capacity of a network to support DSL services, a test device is coupled to a pair of wires (e.g., Tip-Ring) that support DSL services between ATU-C and ATU-R modems. In operation, the test device: samples for a DC line feed or potential on the wires when the ATU-R and ATU-C modems are operatively connected via the wires; samples for AC noise present on the wires when the ATU-R modem is electrically isolated from the ATU-C modem which is operatively coupled to the wires; samples for DSL signals output by the ATU-R modem when the ATU-C modem is electrically isolated from the ATU-R modem; and samples for DSL signals on the wires when the ATU-R modem is operatively coupled to the ATU-C modem via the wires. Based on these samples, the test device determines the capacity of the network to support DSL services.