The present invention relates to a circuit arrangement with which a communication that is subdivided into functional layers is processable by a first layer for a higher layer and/or by a higher layer for the first layer, the first layer being formed by a physical layer and the circuit arrangement featuring at least one port which allows a communication directly with a layer that is higher than the first layer without the communication previously having to pass through the first layer. It also relates to a method for testing a switch for a telecommunication network, according to which the switch with a circuit arrangement is first made available, with which a communication that is subdivided into functional layers is processable by a first layer for a higher layer and/or by a higher layer for the first layer, the first layer being formed by a physical layer and the circuit arrangement featuring at least one port which allows a communication directly with a layer that is higher than the first layer without the communication previously having to pass through the first layer, with data thereafter being output from at least one port which are output in a further step.