The invention relates to a method and a system for controlling an arrangement of a configuration comprising two or more user devices (multi-device configuration) of telecommunication user devices in a public telecommunication network. According to the invention, the supplementary services of the public telecommunication network associated with the first user device or with an identification chip connected to the first user device are activated in such a manner that changes of the supplementary services are effective in the other user devices or the identification chip connected to the respective additional user device of the multi-device configuration at the same time or with a temporal delay. In this manner, when one or more parallel calls are switched to one or more user devices of the multi-device configuration, before delivery of the call, the kind of the call request resulting in a reservation of resources required for completing the call, the system states of the user devices to be called or of the identification chips connected to the user devices and the exchange devices involved therein are determined using an intelligent call control and the call can be delivered in a resource-saving manner.