The present disclosure relates to methods and devices for communication systems comprising an electrically conductive line. The disclosure proposes a method in a line estimation device for determining termination characteristics of an electrically conductive line in a communication system. The method comprises outputting (S100) a test signal to the line, wherein the test signal is a wideband test signal with a bandwidth arranged to provide an adequate measurement time-resolution. The method further comprises receiving (S200) reflections from impedance discontinuities of the line in response to the test signal. The method also comprises forming (S300) a trace of the reflections. The method additionally comprises identifying (S400) at least one anomaly in the trace of reflections. The method yet further comprises determining (S500) termination characteristics of the line based on characteristics of the trace before and after the identified at least one anomaly. The disclosure also relates to corresponding line estimation devices and computer programs.