Implicit in the stop-and-wait scenarios of Figure 2.19 is the notion that the receiver will retransmit its ACK immediately on receipt of the duplicate data frame. Suppose instead that the receiver keeps its own timer and retransmits its ACK only after the next expected frame has not arrived within the timeout interval. Draw timelines illustrating the scenarios in Figure 2.19(b)-(d); assume the receiver’s timeout value is twice the sender’s. Also redraw (c) assuming the receiver’s timeout value is half the sender’s.

Figure 2.19