A remote control system for operating a data processing device from a remote
place
by using a portable device while the user is out or the like is disclosed. In the
system, the portable device associated with the data processing device sends control
data for operating the data processing device to a server via the Internet, and
calls the data processing device via a telephone network. The data processing device
refers to a caller's number communicated when the current call is accepted, and
recognizes, based on the caller's number, whether the call is issued from the portable
device associated with the data processing device. The data processing device downloads
the control data from the server if the call is issued from the portable device,
and executes a process indicated by the downloaded control data.
