A control device includes: a scheme determination unit configured to determine whether a packet to which an identifier of a priority is assigned is transmitted in conformity with a grant-free scheme; a time estimation unit configured to estimate a time in which a traffic volume of the packet is equal to or more than a threshold; and a transfer control unit configured to generate a control signal of a signal transfer device so that the signal transfer device transfers a packet that has arrived at the signal transfer device in the estimated time in accordance with the identifier of the priority. The scheme determination unit determines whether the repeated transmission of the packet is performed. The time estimation unit estimates a time in which the plurality of packets arrive at the signal transfer device a predetermined number of times at predetermined time intervals when it is determined that the repeated transmission of the packets is performed.