frequency and finally fed for transmission via the communication network to the digital signal processor dsp the interface tom and the component codec therefore the clock for the analog interface is synchronized in the switching configuration vop to the clock with which the component codec operates or with which incoming data have been produced so that in the case of bi directional data communication between the switching configuration vop in accordance with fig1 and the component codec no data under run or data overflow arises in either direction of transmission the only proviso for this is that one single frequency is also used in the component codec for processing both received and sent digital values in fig2 a switching configuration voip is illustrated for providing a telephone service via a communication network ip net according to the second embodiment of the present invention such a service is also called voice over ip in contrast to the first embodiment here the digital signals are coded or decoded within the switching configuration voip for this purpose the switching configuration voip apart from an analog interface afe has a digital signal processor dsp a processor cpu of a clock generation unit cgu with an interface ifa the analog interface afe the digital signal processor dsp the clock generation unit cgu the synchronizing logic sl and the oscillator osc correspond to those of the first embodiment so that reference should be made to the description of these components there the processor cpu is connected to the digital signal processor dsp and within the switching configuration voip prepares the digital signals for transmission via a data communication network ip net and transmits or receives these by means of the interface ifa to or from.