Hi The OSLEC module currently only echo cancels on the module wctdm. The only card that ever really used this module is the TDM400P. This card has been removed from products and basically means that the OSLEC echo module is useless. The TDM410P uses the module wctdm24xxp and many echo problems are arrising because there is no echo cancellation being used. (not even the basic Digium ones). It would be favourable if one of the basic Digium echo cancellers were put back into zaptel.