Introduction to Computer Science and Java Programming,
Problem Set 6
2.5+2.5 = 5pts
(for part a, answers may vary depending on the
assumptions they have made. Make sure that their assumptions are
Recall from chapter 5 that a megabyte can store about 2.5 books.
Therefore, to store one million books, one would need 1,000,000 / 2.5
= 400,000 megabytes =
The amount to be transferred is 400,000,000,000 * 8 = 3.2 * 10^12
bits = 3,200,000 Mbits.
At the rate of 10 Mbps, the transfer time
3,200,000 Mbits / 10 Mbits/second = 320,000 seconds
At the rate of 1 Gbps = 1000 Mbps, the transfer time would be
3,200,000 Mbits / 1000 Mbits/second = 3,200 seconds
The store-and-forward protocol would handle a packet repeatedly
getting sent from node A to B but not correctly arriving by finding
another route on the network from node A to B and retransmitting
every lost packet on that new route.
Modifications we could make to
this protocol to handle this particular situation are to number each of