suppose we are sending a large file from host A to host B over a TCP connection with a transmission rate of 1 Gbps where the size of a packet is 1,500 bytes, including both header fields and data. The speed-of-light round-trip propagation delay between these two end systems, RTT, is approximately 20 milliseconds. Assume, for simplicity, that ACK packets are extremely small and can be ignored... How big would the window size have to be (in packets) for the channel utilization to be greater than 80%?