Features available in one communication installation of a communication system are made available system-wide by transmitting an item of feature control information for a subscriber line of a first communication installation to a second communication installation. The item of feature control information is converted into at least one function call, whose associated function is provided by a computer telephony integration (CTI) interface. The function call is transmitted via the CTI interface to the first communication installation. At least one feature control instruction contained in the function call is executed by an administration and maintenance device of the first communication installation. The first communication installation depicts a controlled instance with regard to a feature control, while the second communication installation depicts a controlling instance. This makes it possible to render a feature control existing in the second communication installation usable for the first communication installation.