In a network, there are two end nodes X and Y, and 4 store-and-forward routers connected by 5 links. Each link introduces a bandwidth of 100Mbps and a propagation-delay of 10µs.
The data packet size is 20Kb. Assume as soon as a packet arrives at a router, the router forwards the packet without any nodal-processing-delay or queuing-delay. Assume when a packet arrives at destination Y, the destination immediately replies an acknowledgment packet.
It takes some time for the acknowledgment packet to reach the source X. The total time it takes for source node X to send a packet and receive the acknowledgement is: the time it takes for the packet to reach destination Y plus the time it takes for the acknowledgment to reach source X.
To calculate the effective throughput, both data-transmission and acknowledgement times are considered but notice that throughput is only the amount of data reached at destination (the size of acknowledgement replied to the source X is not counted).
Effective throughput is the size of effective data (data reached at destination Y) over the total time spent to deliver data and acknowledge it.
Assume the size of acknowledgment packet is 60b. What is the delay for a packet to reach destination Y (in micro-second)?
What is the delay for an acknowledgement packet to reach sender X (in micro-second)? What is the effective throughput (in Mbps)?