Automatic speaker recognition on a vocoder link has rarely been explicitly tested. In this paper, we show how the automatic speaker recognition could be used on a vocoder link. In a first experiment where we consider the "coder-link-decoder" speech system as a black box, a classic speaker recognition method (applied on the reconstructed speech) is shown to be able to provide an objective measurement of the voice quality of the vocoder. In a second experiment, the same speaker recognition method is directly applied on the information contained in the coded frames. In latter case, the recognition scores provide an interesting analysis.