Consider the cross-country example shown in Figure 3.17. Suppose that the round-trip time RTT is 30 milliseconds, the channel transmission rate R is 1 Gbps, where G is SI standard (base 10) 109 and not binary (base 2) 230 = 10243, and the size of a packet is 1500 bytes, including both header fields and data. ACK packets are small, and their transmission delay may be ignored.

a) How big is channel utilization (in percent) when a stop-and-wait protocol is used? b) How big would the window size have to be for the channel utilization to be greater than 98 percent when a pipelined protocol is used?

Figure 3.17 Stop-and-wait versus pipelined protocol