Question

A communication channel is of 10kbps bandwidth. The transmission media is fiber optic. We need to
send a window of size 15 packets, where each packet is containing 5000bytes. The total time to
transfer all data from one to another node is:
(a) 50ms
(b) 25ms
(c)75ms
(d)None of these

Answer 1

Task:

A communication channel is of 10kbps bandwidth. The transmission media is fiber optic. We need to send a window of size 15 packets, where each packet is containing 5000bytes. The total time to transfer all data from one to another node is:

(a) 50ms

(b) 25ms

(c) 75ms

(d) None of these

Solution:

Calculate the amount of data that must be transmitted:

$$D = 15 \cdot 5000b = 75000b = 75kb$$

Bandwidth determined by the formula $V = \frac{D}{T}$, based on this we find the total time to transfer all data $T = \frac{D}{V}$.

$$T = \frac{75kb}{10kb/s} = 7.5s$$

Answer: (d) 7.5s.

This answer is right, but I think that there is an error in condition by specifying bandwidth and the correct answer should be (C)