Size of senders window ?

Question

 

Consider a TCP connection using the slow start congestion control scheme with an initial threshold value of 64 kB and a Maximum Segment Size (MSS) of 2 kB. The receiver’s advertised window is initially 32 kB. The first transmission attempt is numbered 0, and all transmission attempts are successful except for the timeouts on attempt number 4. Which of the following represents size of sender’s congestion window at attempt number 10?

Comments

2,4,8,16,32 now timeout (thrshld=16) again 2,4,8,16(reached thrshld)17,18

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As far as I know, The sender's window size = min(Congestion window, Receiver's advertised window)

Here, Receiver's advertised window is 32 KB, so obviously, Threshold = 16 KB (8 MSS)

So, how are we sending till 32 KB (16 MSS) in slow start phase only ?

@Arjun sir, could you please clarify my doubt. Thankyou.

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MSS=2Kb not 1Kb

Answer 1

answer is 20kb

Answer 2

ANS=18KB

IN Starting Cong.threshold=32MSS (as each MSS is of  2 KB and the Cong.threshold is give 64 KB)

Cong. window-> 1  2  4  8  16  1  2  4  8  9

                   Tx-> 0  1  2  3   4   5  6  7  8  9

as at tx=4 timeout occurs,cong window at tx=5 becomes 1 & cong.threshold=16/2 =8MSS

at tx=9 cong.window=9 MSS which is equal to 18kB as each MSS is 2KB.