The invention relates to a switching device for the alternate connection of at least one first test port or of a second test port to a measuring-device connection, where the measuring-device connection provides at least one test-signal input. The test-signal input is connected to a first signal path and to a second signal path, where the first signal path is connected alternately to the first or to the second test port, and the second signal path is connected at least to the respectively other test port.