3. () (4) Consider the data transfer between two hosts A and B, with the stop-and-wait protocol, rdt3.0. A is located on the West Coast of the United States and B is located on the East Coast. The speed-of- light round trip propagation delay between A and B, RTT, is approximately 30 milliseconds. Suppose that A and B are connected by a channel with a transmission rate, R, of 1Gbps. Given the packet size, L, of 1500 bytes, determine the channel utilization. () 16] Folowing the problem (), consider the pipelined technique instead of stop-and-wait protocol How big would the window size have to be for the channel utilization to be greater than 98%? (ii) [2) What does the receive window (rwnd) field in a TCP segment indicate? (iv) 12+2] Why are the flow control and congestion control needed