A solution for controlling activities to be carried out in a network element in a flexible and safe manner. A data transmission network includes a network element, which includes data transfer means for transmitting and receiving data from the data transmission network, which data includes one or more commands: processing means for processing the data provided in a specified format; and control means for modifying the received command into a format required by the processing means. The control means includes a driver the origin of which can be verified with the help of an electronic signature; and one or more functions that control the operation of the processing means, which can only be initiated by the driver the origin of which has been verified with the help of the electronic signature.