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Why in TCP's Go-Back-N Algorithm window size(N) has to be smaller than the sequence number space(S): S>N? I tried figuring it out myself but don't quiet get it

Valera
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    I suggest adding a quote from the relevant specification that describes the Go-Back-N Algorithm. I just looked at the RFC and wasn't able to quickly locate that section. – user3386109 Feb 10 '15 at 23:54

1 Answers1

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Assume that sequence space was four (sequence numbers 0,1,2,3). Lets say window size was also 4. Sender sends 4 packets with sequence numbers (0,1,2,3). Receiver receives all four packets. So it sends 4 acknowledgements(0,1,2,3). Now assume all acknowledgements are lost. Sender will resend all four packets but receiver will assume they're the new ones. To avoid confusions arising from lost acknowledgements, we keep n < s

Abhay Aravinda
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