Transceiver, optical transmitter, port-based switching method, program, and storage medium

In a transceiver having a plurality of ports, switching is determined on a port basis. A transceiver that is redundantly configured, has a plurality of interface ports, and implements serial communications of switching-control information for each interface port is characterized by including a switching-control circuit for creating the switching-control information items and implementing control so that the interface ports are switched, a parallel-to-serial conversion circuit for serial-converting the switching-control information items, and a serial-to-parallel conversion circuit for parallel-converting the switching-control information items that have been serial-converted.