[svlug] Reprise: Adjusting retransmission parameters

[Jeffrey Siegal]

Eric Nickell wrote:
> So that means that in a very bursty environment, such as this, it sees a
> relatively fast turnaround, so it hammers pretty hard on retransmitting
> when transmission goes away for a while?  

In essence, yes.  It waits just long enough to be reasonably confident
that the packet really has been dropped, and then sends it again.

> Hmm. Question: Do dropped packets have any effect on the retransmission
> timer?

There is an exponential backoff, but if your drop rate is only 1% or so,
as you suggested, then this won't make much difference because the
backoff is pretty slow and won't drop more than one packet in a row very
often.  If the drop rate is much higher than that, then, like I said
earlier, you won't get acceptable results from TCP until you get the
connection to work better.