Kurose and Ross Edition 6 Exercise 1 Question R19 (Page No 69)

Question

Suppose Host A wants to send a large file to Host B. The path from Host A to Host B has three links, of rates R1 = 500 kbps, R2 = 2 Mbps, and R3 = 1 Mbps.

1. Assuming no other traffic in the network, what is the throughput for the
   file transfer?
2.  Suppose the file is 4 million bytes. Dividing the file size by the throughput, roughly how long will it take to transfer the file to Host B?
3. Repeat (a) and (b), but now with R2 reduced to 100 kbps.

Answer 1

a)Throughput for file transfer $= 500\text{kbps}$

b) Time taken for transfer the file to host $\text B=\frac{(4\times {10}^6)\times 8}{(500\times{10}^3} = 64\; \text{seconds}$

c)For R2, Throughput = $100\text{kbps}$, Time taken for transfer$ = \;\frac{4\times{10}^6\times 8}{100\times{10}^3}= 320\; \text{seconds}$