In some of the final exam and review questions, the question asks about the behaviour of a sender’s congestion window after it receives 3 acks for the same sequence number. However, we only deal with loss on the triple duplicate ack, meaning 4 acks for the same sequence number.
On the exam, if we are presented with a similar question, are we to interpret 3 acks for the same sequence number as being the triple duplicate ack?
Or am I interpreting it wrong?
Example is Q24.C from the December 2017 exam:
While its congestion window is at 18KB, the sender receives three acknowledgments for the same sequence number. How long after receiving the third acknowledgment will it take for the sender’s congestion window to be at least 11KB again?