Data processing device, data processing system, data processing method, data processing program and recording medium storing the program

摘要

A server unit (300) transmits dummy packets to be used for computing an effective transmission speed of a network (200) to a client unit (400) by way of the network (200) at timing prior to the transmission of data packets containing data at a speed higher than a transmission speed of the data packets. The transmission speed detector (422) of the client unit (400) computes the effective transmission speed of the network (200) on the basis of the detected amount of the lost dummy packets on the network (200). The server unit (300) specifies a transmission speed for the data packets on the basis of the effective transmission speed and transmits the data packets to the client unit (400) by way of the network (200) at the specified transmission speed.