Quiz: Throughput
Suppose: Host A has a large file of size F bits to send to Host B File is split into N packets, each of length L bits (i.e., N=F/L) Ignore propagation delay for now
q Ques&on 1: how long does it take for the file to arrive at B? A: (N+2)L/R = (F+2L)/R
q Ques&on 2: what is the average throughput achieved when sending the file?
Copyright By https://powcoder.com 加微信 powcoder
A: NL/[(N+2)L/R]=NR/(N+2) = FR/(F+2L) = R/(1+2L/F) Note: throughput = number of total bits sent / total &me taken
Quiz: Throughput
Host A L d/3 d/3 d/3 Host B
Suppose: Host A has a large file of size F bits to send to Host B File is split into N packets, each of length L bits (i.e., N=F/L)
Do NOT ignore propagation delay (assume prop. speed = s m/s)
q Ques&on 1: how long does it take for the file to arrive at B? A: (N+2)L/R + d/s = (F+2L)/R + d/s
q Ques&on 2: what is the average throughput achieved when sending the file?
A: NL/[(N+2)L/R +d/s]=FR/[(N+2)L + dR/s] = FR/[F+2L+dR/s]