A server transmits a probe packet to a terminal, estimates a bandwidth of the network based on information returned from the terminal, calculates a rate used for performing compression coding of screen information and/or an accompanying audio signal, generated by an application on a virtual terminal on the server, so as not to exceed the estimated bandwidth, encodes the screen information and/or the accompanying audio signal at the calculated rate, stores the encoding result in a packet of a predetermined protocol to transmit the packet.