PURPOSE: To attain impartial service while handling lots of data by devising a device such that a reception data is controlled with a large limitted value when a detected storage residual amount is much and the reception data is controlled with a small limitted value when the storage residual amount is less.

CONSTITUTION: A storage section 30 stores the data received via a line control section 70 and in a residual amount detection section 40, the storable residual amount (residual amount of storage section) of the storage section 30, that is, the remaining storage capacity of the storage section 30 is detected. Moreover, a transmission control section 50 controls data transmission from a store and forward switching device 100 and a reception control section 60 controls the data reception of the device 100. The line control section 70 is controlled by the control sections 50, 60 to apply connection control to (n) lines (1-n) connected to the device 100. Then the device control section 10 controls dynamically the reception data amount to the device 100 corresponding to the storage enable residual amount of the storage section 30 detected by the detection section 40. Thus, lots of data are inputted even while applying impartial service.