A method is used to determine information about a communication channel using an adaptive filter coupled to the channel. The adaptive filter includes adaptive filter coefficients. The filter coefficients are compared to filter coefficient thresholds. A determination is made whether one of a communication link and a channel fault exists. If a channel fault exists, a determination is made whether, i) a cable open condition exists in the channel, and ii) a cable short condition exists in the channel. An indication is made whether the channel is one of linked, open, and shorted.