Performance of a Network Examples

Bandwith

Ex: A network with a bandwidth of 10 Mbps can pass only average of 12’000 frames per minute with each frame carrying an average of 10’000 bits. What is throughput of this network?

T= \frac{12'000*10'000}{60} = 2Mpbs

Latency(Delay)

\begin{align*}
Latency &= propagation~time \\&+ transmission~time \\&+ queuing~time \\&+ processing~delay
\end{align*}

Transsmission~time=(Message~size)/Bandwidth

Ex: What are the propagation time and transmission time for a 25kB message if the bandwidth is 16 bps?

Assume that the distance between sender and receiver is 12’000 km and he progpagation speed is 2.4*10^8m/s

Propagation~time= \frac{12'000*1'000}{2.4*10^9} \cong 50ms

Transmission~time= \frac{2500*8}{10^9} = 0.020ms

Not: Eğer soruda transmission negligible derse hesaba katmıyoruz.

Jitter: Paketler arasındaki varış sürelerindeki dağınıklık.

Ex: We have a channel with 4kHz bandwidth. If we want to send data at 00kbps what is the minimum SNRdb? What is SNR?

Ex: What is the total delay for a frame size 5 million bits is sent on a line with 10 routers each having a queuing time of 2 \mu s and a processing time of 1 \mu s .

The length of the link is 2000km the speed of propagation is 2*10^8m/s and bandwith is Mbps?

What is the total delay?