Consider the effect of using slow start on a line with a 10-msec round-trip time and no congestion. Assume the maximum segment size is 4KB and the threshold is set to 16KB initially in congestion control algorithm. How long does it take before a window of 24KB data can be sent at once?
migrated from stackoverflow.com Feb 25 '11 at 6:02
With slow start, the first RTT sends out 1 segment (or 4KB), the 2nd RTT sends out 2 segments (or 8KB), the 3rd 4 segments (or 16KB), the 4th 8 segments (or 32KB) which is greater than the threshold value now you can only increase the data linearly (not exponentially) will add 1 MSS which is 4KB (5th RTT) and one more 4KB (6th RTT), which totally makes 60 msec.
i hope i didn't make any mistakes...