Abstract: Communication connections in a communication system with a communication terminal are assigned to a first communication device, which can be registered at a second communication device, and used in a packet-oriented network by way of which the communication terminal is connected to the first and the second communication devices. As a consequence of a registration performed by a subscriber the communication terminal is signed off from the first communication device and is assigned to the second communication device. In the case of a communication connection initialized at the communication terminal a check is carried out to determine whether the initiated communication connection to a destination device defined by a subscriber number reserved in the communication system is to be realized.