Suppose host A reaches host B via routers R1 and R2: A-R1-R2-B. Fast retransmit is not used, and A calculates Time Out as 2×EstimatedRTT. Assume that the A-R1 and R2-B links have infinite bandwidth; the R1-→R2 link, however, introduces a 1-second-per-packet bandwidth delay for data packets (though not ACKs). Describe a scenario in which the R1-R2 link is not 100% utilized, even though A always has data ready to send. Hint: Suppose A's Congestion Window increases from N to N + 1, where N is R1's queue size.