This object specifies the number of symbols per codeword being used by the ATU-R for upstream messages on an interleaved channel during the training sequence. The ATU-C can force the ATU-R to fallback from this value based on the aggregate data rate achieved during training. It is desirable to choose a large codeword size to minimize overhead. However, increasing the codeword size increases the possibility of not being able to correct errors in the data delivered by a frame.