If the bandwidth of a medium is 100 Mbps and round-trip time is 50 microseconds then calculate the sequence bits in Go Back N ARQ flow control policy is applied and frame size 100 bits has to be transfer.
(A) 5
(B) 6
(C) 7
(D) None of these


Answer: (B)

Explanation: Given,
Round trip time (RTT) = 50 microseconds = 50×10^-6 sec
And, transmission time (Tx) = (data size) / (bandwidth) = 100 Mbps / 100 = 100×10^-6 / 100 = 1×10^-6 sec

Therefore, sequence bits = log₂{(RTT) / (Transmission time)} = {(50×10^-6 sec) / (1×10^-6 sec)}
Sequence bits = log₂(50) = 5.64 ≈ 6 bits.
Take ceiling value for minimum.

So, option (B) is correct.


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