[Solution to Problem] A load balance control unit, which is included in a transmission apparatus for transmitting a plurality of units of data, each being a piece of transmission data delimited by a given data length, to an opposite apparatus via a plurality of transmission lines, includes sorting buffers which are provided for the respective transmission lines; a threshold setting element which sets upper limit retention threshold values for the respective sorting buffers; and a sorting determination element which determines, for each of the units of data, in which of the sorting buffers the each of the units of data is to be written, taking into consideration retention states and the upper limit retention threshold values of the respective sorting buffers, and a data amount of the each of the units of data.