Question
Consider sending a large file of F bits from Host Ato Host B. There are three links (and two switches) between Aand B, and the links are uncongested (that is, no queuing delays). Host Asegments the file into segments of S bits each and adds 80 bits of header to each segment, forming packets of L = 80 + S bits. Each link has a transmission rate of R bps. Find the value of S that minimizes the delay of moving the file from Host Ato Host B. Disregard propagation delay.
Answer
Consider the given data:
Number of links =3
Number of switches=2
File size=F bitsze of each Segment= S bits
Number of segments=F/S
Header size= 80 bits
Packet size(L)=80+S bits
Transmission rate(R)=R bps
Transmission delay(Tdelay)=L/R
=(80+S)/R seconds
Time (T) required for the first packet to be transmitted to destination:
T=Tdelay * Number of links
=(80+S)/R *3
