A transport apparatus configured to transport a main signal received via one of a plurality of ports to any of the plurality of ports, the transport apparatus includes: a plurality of main signal processing circuits configured to extract a monitoring control signal from the main signal, the plurality of main signal processing circuits being provided to correspond to the plurality of ports, respectively; a monitoring controller configured to receive the monitoring control signal from the plurality of main signal processing circuits; and a serial interface configured to connect the plurality of main signal processing circuits with the monitoring controller on a ring-shaped bus to transfer a serial frame, wherein the serial frame has a mapping field to which the monitoring control signal is mapped.