Suppose Host A wants to send a file of size F = 1500 bytes to Host B. The path from Host A to Host B has three links having rates R1 = 500 kbps, R2 = 1 kbps, and R3 = 2 Mbps, respectively.
Assume there is no other traffic on this network.
Assume negligible processing delays. Assume the packets have a size of L = 520 bytes (20 bytes are for header - carry no data from the file - 500 bytes for payload). Assume no other traffic in the network and negligible propagation delay. Answer the following questions:
a) What is the end-to-end delay experienced by the first transmitted packet?
b) What is the end-to-end delay from the time Host A starts transmitting the file to the time when the file is completely received at Host B? Motivate your calculation.
c) How much queuing delay does the second packet experience? Motivate your calculation.
d) How much queuing delay does the third packet experience? Motivate your calculation.
e) What is the end-to-end delay from the time Host A starts transmitting the third packet to the time when the file is completely received at Host B? When answering this question, assume a propagation delay of 100 msec in the first link, 300 msec in the second link, and 200 msec in the third link. Motivate your calculation.
f) How much queuing delay does the second packet experience in the case where R1 =1 kbps, R2 = 2 Mbps, and R3 = 500 kbps, respectively? Motivate your calculation.
(1 msec = 103 seconds)
(1 kbit = 103 bits)
(1 Mbit = 106 bits)
(bps = 1 bit/second)
(1 byte = 8 bits)