A method for optimizing resource allocation for signal conditioning of DSL or other signal lines includes developing a signal quality metric using crosstalk interference and, optionally, signal to noise level. Use of existing pilot tone training selectively assigned to signal lines allows determination of the signal quality metric. A threshold level is selected and all signal lines having a signal quality metric above the threshold level are assigned crosstalk cancellation resources. Because the total number of signal lines requiring crosstalk cancellation is not known at the beginning, a particular threshold level may result in allocation of more than the available resources or allocation of significantly less than the available resources. When this happens the threshold level may be adjusted and the process repeated until crosstalk cancellation resources are assigned up to a usable limit.