A network element includes control entities (102, 103) and controllable entities (104-105) such as line interface units. The control entities configure the controllable entities to enable the network element to operate in a data transfer network. Each control entity maintains a configuration data-set in accordance with configuration information based on data received from the data transfer network and transmits the configuration data-set to one or more controllable entities. The control entity applies a configuration rule on the configuration information and updates the configuration data-set on the basis of the result of the configuration rule. The configuration rule is stateless so that its result is independent of earlier results of the configuration rule and of earlier configuration information. The control entities are enabled to keep their configuration data-sets nearly congruent with each other because they use the same configuration information and the same stateless configuration rule.