Communication system provided with control apparatus between local network and external network

摘要

A communication system includes a local terminal apparatus connected with a local network, a remote terminal apparatus connected with an external network, and a control apparatus interposed between the local network and the external network. The local terminal apparatus includes a reply section for returning an answer signal including a status information of a processing executing section via the local network in response to a request signal received via the local network. The control apparatus includes a gateway section for receiving the request signal transmitted from the remote terminal apparatus via the external network, and thereafter, transmitting the received request signal to the local terminal apparatus via the local network, and for receiving an answer signal corresponding to the request signal from the local terminal apparatus via the local network, and thereafter, transmitting the received answer signal to the remote terminal apparatus via the external network.