Abstract: A signal acquisition device captures signals from a telecommunication line such as a local loop. The captured signals are spectrally analyzed using a signal-processing unit. The output of the signal-processing unit—in the form of a test spectrum—is provided to a signal identification system. The signal identification system comprises at least one of a plurality of spectra of known signals stored as templates. Using a matching algorithm, the spectrum of the test signal (unknown signal) is correlated with spectra of at least two known signals. The unknown signal is determined to be the same type as that of the known signal with whose spectrum the unknown signal produces the largest absolute correlation score. Alternatively, an unknown signals is determined to be that of a known signal if a correlation of both signals results in a score the absolute value of which is greater or equal to a predetermined threshold level.