Abstract: A layer of network elements is provided between already existing physical networks and service providers or users. The network elements communicate via interfaces not only with each other, but also with the physical networks which are connected to them. This layer, which is implemented by network elements distributed in the network, enables the network user to access the existing network resources available in the physical, subjacent networks. This enables all available basic and value-added services to be used. The required and generated data are collected separately according to users or service providers in the relevant physical networks, and are managed and made available for further processing.

Abstract: Telephone calls are handled via the Internet between an interworking unit relating to the calling subscriber and an interworking unit relating to the called subscriber. At least the telecommunications network to which the calling subscriber belongs as well as the interworking units are operated by the same provider. Access by a calling subscriber to the interworking unit and the passing on of the dialed telephone number of the called subscriber to the interworking unit are made dependent on the identification of the call as an Internet telephone call and dependent on the result of an access authorization check. Charging for use of the telephone network and of the Internet for such a call does not commence until the connection is made, as in the case of a call which uses only the telephone network.

Abstract: A distributed operating system for controlling network elements in a data or telecommunication network in which the operating system controls a data and communication network consisting of various underlying physical base networks. These base networks consist of network elements that provide various network (basic) services and network functions and can be controlled by system-specific calls. Accordingly, there exist higher-ranking network elements that are equipped with specific operating system components and execute basic functions independent of the physical subnetworks, such as accessing the physical base networks, distributing the calls of basic services, and converting the calls into the corresponding system-specific formats.