testS

Question

The round trip delay between X and Y is given as 60 ms and bottle neck bandwidth of link between X and Y is 512 KBps. What is the optimal window size (in packets) if the packet size is 64 bytes and channel is full duplex

Comments

You sure about it.

Does using full duplex affect it anyway?

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window size =(1+2a) where a =Tp/Tt
so it comes 481 bits

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@Rajesh,dont use formula

Answer 1

it is 240 packets only. if the link is half duplex then in 1 rtt you will be able to send 1 window. but if link is full duplex you can send 2 windows in  1 rtt. so 2 windows size will become 60*512B. so number of packets per window will be 240

Comments

Why in full duplex we can send 2 Windows in RTT

Answer 2

first find the bandwidth delay product = bandwidth * RTT = 512KBps * 60ms = 30720B.

If the size of the each packet is 64B.

then total no of packets = 30720B/64B = 480 packets.

IT is given wrong in made easy workbook