Switching device of a communication network, which is configured to set a rule in a signal processing device provided separately from the switching device, preferably as a network coupling device, or in or as a component of a network coupling device, in the same communication network, which enables and/or instructs the signal processing device to detect frequency-coded signals that are contained in a payload stream of a telecommunications connection, and to transmit these independently from a payload stream of the telecommunications connection to the switching device.