A network element of a software-defined network includes functional entities (321-325) capable of transferring data between each other and providing connections to other network elements. One or more of the functional entities are configurable with configuration data received from a controller of the software-defined network. The network element is adapted to transmit, to the controller, entity-specific capability descriptors related to the functional entities configurable with the configuration data. Each entity-specific capability descriptor expresses operations capable of being carried out by the respective functional entity. As the controller is made aware of the capabilities of the functional entities, the goal of the software-defined networking to provide controlled management of the data-forwarding functionality of a network element as a whole can be extended to the functional entities, e.g. line interface modules, so that each functional entity can be configured individually in accordance with the capabilities and resources of the functional entity.