In order to enable prediction of communication having high quality requirements, this communication device is provided with: a determination unit that determines that a change has occurred in the communication state of communication which is performed, with a device connected to a network, by each of a first terminal and a second terminal communicating with the device; and a derivation unit that, when the change in the second terminal is determined to be being occurring in synchronization with the change in the first terminal, derives a second change time at which the change occurs in the second terminal, on the basis of a first change time at which the change occurs in the first terminal.