Abstract: A line state analyzer (42, 116) is provided for determining if two asynchronous digital subscriber line modems (12, 34) have entered a training stage or if some error has occurred prior to entering the training stage, and to assist in determining which of the modems is at fault. The analyzer includes a frequency detection circuit (50) to detect the various signals exchanged by the modems prior to entering the training stage. The information detected by the detection circuit is presented on a visual display (51, 123). Operator perceptible indicia (51, 119) may be provided to assist the operator in identifying what the line state analyzer has determined.