In Case of AIMD(Additive Increase/ Multiplicative Decrease): -
- Start with given MSS (Min Sequence Size)
- Increase the window size in multiples of MSS till the slow start threshold occurs
- Once the threshold reached, increase the window size by 1 MSS till the timeout occurs
- Once the timeout occurs, reduce threshold to half of current window size and again start from given start MSS.
$t=0$
$1\ \textsf{MSS}= 2 \ KB$
$W_{\textsf{threshold}} = 32\ KB$
$| \rightarrow \text{denotes } 1$ $\textsf{RTT}$
$\small \underbrace{2\ \overset{+1 \textsf{ MSS}}{ |_{t+6}}\ 4\ \overset{+2\textsf{ MSS}}{ |_{t+12}}\ 8\ \overset{+4\textsf{ MSS}}{|_{t+18}}\ 16\ \overset{+8\textsf{ MSS}}{|_{t+24}}\ }_{\textsf{exponential increase}}32\ \underbrace{ \overset{+1\textsf{ MSS}}{|_{t+30}} \ 34\ \overset{+1\textsf{ MSS}}{|_{t+36}}\ 36\ \overset{+1\textsf{ MSS}}{|_{t+42}}\ 38\ \overset{+1\textsf{ MSS}}{|_{t+48}}\ 40\ \overset{+1\textsf{ MSS}}{|_{t+54}}\ 42 \ \overset{+1\textsf{ MSS}}{|_{t+60}}\ 44}_{\textsf{linear increase after theshold}}$
$\therefore$ The size of the congestion window(in KB) at time $t+60$ ms after all acknowledgments are processed is $44$ KB