A communication apparatus complying with the ITU-T Recommendations v.34 and control method thereof are disclosed. The communication apparatus predicts a timing at which reception of image data in an amount of the error frames sent from another communication device is terminated, based on the number of error frames which are not normally received when receiving image data from the another communication device through a primary channel. The communication apparatus controls to shift from the primary channel to a control channel in accordance with the predicted timing when the image data is received in an amount of the error frames on the primary channel from the another communication device.