Suppose that between A and B there is a router R. The A–R bandwidth is infinite (that is, packets are not delayed), but the R–B link introduces a bandwidth delay of one packet per second (that is, two packets take 2 seconds, etc.). Acknowledgments from B to R, though, are sent instantaneously. A sends data to B over a TCP connection using slow start but with an arbitrarily large window size. R has a queue size of one in addition to the packet it is sending. At each second, the sender first processes any arriving ACKs and then responds to any timeouts.

(a) Assuming a fixed TimeOut period of 2 seconds, what is sent and received for T = 0, 1,..., 6 seconds? Is the link ever idle due to timeouts?

(b) What changes if TimeOut is 3 seconds instead?