A communications device for detecting instability resulting from non-linear impairments and resetting at least one equalizer of an end device (102, 102a), wherein a set of equalization coefficients of the end device is determined and sent to the end device by the communication device, the communications device comprising: a data storage device configured to store an equalization instability threshold; and a processor (114, 116) configured to monitor an equalization parameter for the at least one equalizer of the end device (102, 102a), to determine whether the equalization parameter exceeds the equalization instability threshold, and in response to the equalization parameter exceeding the equalization instability threshold, to reset the equalizer, and characterized by the equalization instability threshold being a maximum power threshold for total power in all secondary equalizer taps and the equalization parameter being a sum of the total power in all secondary equalizer taps or the equalization instability threshold being a predetermined percentage of secondary equalizer taps exceeding a maximum power threshold and the equalization parameter being the power in all the secondary equalizer taps measured individually against the maximum power threshold, wherein the secondary equalizer taps comprise all tap coefficients excluding a main coefficient tap. a data storage device configured to store an equalization instability threshold; and a processor (114, 116) configured to monitor an equalization parameter for the at least one equalizer of the end device (102, 102a), to determine whether the equalization parameter exceeds the equalization instability threshold, and in response to the equalization parameter exceeding the equalization instability threshold, to reset the equalizer, and characterized by the equalization instability threshold being a maximum power threshold for total power in all secondary equalizer taps and the equalization parameter being a sum of the total power in all secondary equalizer taps or the equalization instability threshold being a predetermined percentage of secondary equalizer taps exceeding a maximum power threshold and the equalization parameter being the power in all the secondary equalizer taps measured individually against the maximum power threshold, wherein the secondary equalizer taps comprise all tap coefficients excluding a main coefficient tap. to monitor an equalization parameter for the at least one equalizer of the end device (102, 102a), to determine whether the equalization parameter exceeds the equalization instability threshold, and in response to the equalization parameter exceeding the equalization instability threshold, to reset the equalizer, and characterized by the equalization instability threshold being a maximum power threshold for total power in all secondary equalizer taps and the equalization parameter being a sum of the total power in all secondary equalizer taps or the equalization instability threshold being a predetermined percentage of secondary equalizer taps exceeding a maximum power threshold and the equalization parameter being the power in all the secondary equalizer taps measured individually against the maximum power threshold, wherein the secondary equalizer taps comprise all tap coefficients excluding a main coefficient tap.