Suppose A is connected to B via an intermediate router R, as shown in Figure 2.37. The A–R and R–B links each accept and transmit only one packet per second in each direction (so two packets take 2 seconds), and the two directions transmit independently. Assume A sends to B using the sliding window protocol with SWS = 4.

(a) For time = 0, 1, 2, 3, 4, 5, state what packets arrive at and leave each node, or label them on a timeline.

(b) What happens if the links have a propagation delay of 1.

0 seconds but accept immediately as many packets as are offered

(i.e., latency = 1 second but bandwidth is infinite)?

Figure 2.37

A (R) (B)