| 摘要 |
PROBLEM TO BE SOLVED: To reduce a size and costs of a device by reducing the loss of a light signal. SOLUTION: A switching device comprises two switches SW0 and SW1; branch sections 10 and 11 for branching and outputting the inputted signal to the switches SW0 and SW1; a plurality of selection switches SS 10 and SS 11 for selecting one of signals outputted from each output port for outputting to an external output-side transmission line; and a device redundancy switching section 2 that performs control for switching and connecting each signal that is branched by the branch sections to a different selection switch when the switches SW0 and SW1 operate normally, and performs control for switching and connecting signals branched to the other switches SW0 and SW1 to a preferential external output-side transmission line, when a failure occurs to the other switches SW0 and SW1 when one of the switches SW0 and SW1 operates abnormally. |
