A transmission device includes: an FPGA that configures a port processing circuit in a line interface which communicates with an XFP; and a flash memory that stores configuration information for configuring, in the FPGA, a measurement circuit that measures and acquires a transmission parameter for use in communication between the XFP and the port processing circuit; and an FPGA control unit that configures the measurement circuit in a portion of the port processing circuit based on the configuration information read from the flash memory, upon detecting a loop-back connection with the XFP. The measurement circuit measures and acquires a transmission parameter. The FPGA control unit sets the acquired transmission parameter to the line interface, and reconfigures the measurement circuit in the port processing circuit.