Loss Differentiation Algorithms (LDA) are currently used to deter-mine the cause of packet losses with an aim of improving TCP performance over wireless networks. In this work, we are interested in the distinction between losses due to interferences on 802.11 links from those due to congestions. To this end, we compare different LDA schemes existing in the literature and a proposal of a cross-layer LDA which use MAC parameters. The efficiency of our solution is then demonstrated through simulations.