How to understand this sentence?
Hello, when I read an article, I meet one sentence: "An IRN sender, therefore, uses a low timeout value of RTOlow only when there are a small N number of packets in ﬂight" .
I am confused about it's meaning. I am not sure whether my understanding is right: timeout value=RTOlow only when the number of packets in flight = N ?
Any help will be greatly appreciated.