A communication device for a redundancy network, the communication device comprising: unit modules independently of each other according to each port characteristic between a plurality of input ports and a plurality of output ports and configured to perform a redundancy data input and output processing, wherein a redundancy frame is received together with a transmission target frame through an input data port and an input redundancy port included in the plurality of input ports, but the transmission target frame and the redundancy frame are duplicately transmitted through an output data port and an output redundancy port to perform redundancy data transmission, wherein each of the unit modules corresponding to each port comprises: a frame checker configured to check whether the received transmission target frame is a transmission target; a port commander configured to perform at least one of determination of an output port and determination of a tag insertion or removal method according to a check result of the frame checker; and a frame maker configured to transmit a frame through one of the plurality of output ports determined by the port commander by independently performing tag insertion or removal in the unit module according to a method determined by the port commander, wherein the frame maker performs a buffering processing of another output port that performs relatively fast data transmission with a cut-through buffer method while performing a buffering processing of a corresponding output port that performs relatively slow data transmission with a store-and-forward buffer method. unit modules independently of each other according to each port characteristic between a plurality of input ports and a plurality of output ports and configured to perform a redundancy data input and output processing, wherein a redundancy frame is received together with a transmission target frame through an input data port and an input redundancy port included in the plurality of input ports, but the transmission target frame and the redundancy frame are duplicately transmitted through an output data port and an output redundancy port to perform redundancy data transmission, wherein each of the unit modules corresponding to each port comprises: a frame checker configured to check whether the received transmission target frame is a transmission target; a port commander configured to perform at least one of determination of an output port and determination of a tag insertion or removal method according to a check result of the frame checker; and a frame maker configured to transmit a frame through one of the plurality of output ports determined by the port commander by independently performing tag insertion or removal in the unit module according to a method determined by the port commander, wherein the frame maker performs a buffering processing of another output port that performs relatively fast data transmission with a cut-through buffer method while performing a buffering processing of a corresponding output port that performs relatively slow data transmission with a store-and-forward buffer method. a frame checker configured to check whether the received transmission target frame is a transmission target; a port commander configured to perform at least one of determination of an output port and determination of a tag insertion or removal method according to a check result of the frame checker; and a frame maker configured to transmit a frame through one of the plurality of output ports determined by the port commander by independently performing tag insertion or removal in the unit module according to a method determined by the port commander, wherein the frame maker performs a buffering processing of another output port that performs relatively fast data transmission with a cut-through buffer method while performing a buffering processing of a corresponding output port that performs relatively slow data transmission with a store-and-forward buffer method.