A communication device includes multiple output terminals configured to output, through an interface including at least a signaling channel through which a baseband signal is transmitted in one direction and a bidirectional control channel used for control, the baseband signal, one or more input terminals configured to be input with the baseband signal through the interface, and a control unit, the multiple output terminals including a primary output terminal through which the control is preferentially performed with another device connected to the one or more input terminals and one or more further secondary output terminals, and the control unit configured to perform a control of notifying another device connected to the secondary output terminal of a function of another device connected to the one or more input terminals as a function of the communication device via the control channel.