The communication system includes: first terminal devices connected to a transmission path and having terminal information; a second terminal device connected to the path and sending an information request requesting the information from the first terminal device; a first superimposing apparatus interposed between the first terminal device and the path; and a second superimposing apparatus interposed between the second terminal device and the path and receiving the request from the second terminal device. The first superimposing apparatus acquires the information from the connected first terminal device at predetermined timings and stores it. Upon receiving the request, the second superimposing apparatus sends the request to the first superimposing apparatus using a superimposed signal superimposed on a transmission signal transmitted via the path. Upon receiving the request, the first superimposing apparatus sends the information to the second superimposing apparatus using the superimposed signal. Upon receiving the information, the second superimposing apparatus provides the information to the second terminal device.