multiples of 512 bits, and each repeater will insert a store-and-forward delay equivalent to 20-bit
Assume a 10Mbps Ethernet has two nodes, A and B, connected by a 360m cable with three
repeaters in between, and they each have one frame of 1,024 bits to send to each other. Further assume
that the signal propagation speed across the cable is 2*10^8 m/sec, CSMA/CD uses back-off intervals of
multiples of 512 bits, and each repeater will insert a store-and-forward delay equivalent to 20-bit
transmission time. At time t=0, both A and B attempt to transmit. After the first collision, A draws K = 0
and B draws K = 1 in the exponential back-off protocol after sending the 48bits jam signal.
a. What is the one-way propagation delay (including all repeater delays) between A and B in
seconds? At what time is A's packet completely delivered at B?
b. Now suppose that only A has a packet to send and that the repeaters are replaced with switches.
Suppose that each switch has an 8-bit processing delay in addition to a store-and-forward delay.
At what time, in seconds, is A's packet delivered at B?
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