An arrangement, method, and node for configuring subscriber lines in a digital access network. A configuration tool downloads configuration parameters from the network into the access nodes, which configure the subscriber lines according to the configuration parameters. An automated monitoring tool monitors performance parameters for the subscriber lines. The monitoring tool compares a value of a first monitored performance parameter on each subscriber line with a predefined threshold value, and based on a result of the comparison, either changes a value of a first configuration parameter or repeats the monitoring of the first performance parameter.