An electronic device which is able to acknowledge downloaded data packets at a maximum download speed includes at least one processor and a storage device. The resource allocations of a physical layer of a network are obtained, and a transmission volume of a download link of the physical layer is calculated. The rate of issuing and transmitting acknowledgments through an upload link, based on respective sizes of data packets and acknowledgments, is also calculated. A determination is made as to whether the rate of issuing acknowledgments per download packets should be changed to achieve effectively equal speed of issuing acknowledgments through the upload link and the manner of the issue is adjusted accordingly.