A redundant communication apparatus includes a determining unit and a transmitting unit. The determining unit determines an upper limit of a redundancy level when transmission waiting data in a transmission apparatus is made redundant and transmitted, based on a data quantity of the transmission waiting data and a communication speed of a communication line between a reception apparatus that is a transmission destination of the transmission waiting data and the transmission apparatus. The transmitting unit causes the transmission waiting data to be made redundant at a redundancy level that is equal to or less than the upper limit determined by the determining unit and transmits the data to the reception apparatus via the communication line.