Question

Let the size of congestion window of a tcp connection be 32 kb when a timeout occurs. The round trip time of the connection is 100 msec and the maximum segment size used is 2 kb. The time taken (in msec) by the tcp connection to get back to 32 kb congestion window is _________.

Answer 1

Given that at the time of Time Out, Congestion Window Size

is 32KB and RTT = 100ms,

When Time Out occurs, for the next round of Slow Start,

Threshold = size of congestion window2 ,

Threshold = 16KB

Suppose we have a slow start ⇒2KB∣4KB∣8KB∣16KB

(As the threshold is reached, Additive increase starts)

∣18KB∣20KB∣22KB∣24KB∣26KB∣28KB∣30KB∣32KB

Here | (vertical line) is representing RTT so the total number of vertical lines is

11×100ms=1100msec and so this is the answer.