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Rwin
Posted: Tue Aug 21, 2001 12:56 pm
by chaobox99
I just read about the Cablenut Dictator words in broadband nut forum. The "correct" RWIN should be approximately
RWIN = max. bandwidth x average RTT
If this calculation is correct, is that mean we don't have to try any other values?
So, how does this calculated RWIN compare to the default 64240,128480,256960,513920?
Posted: Tue Aug 21, 2001 1:05 pm
by Lobo
Very easy, use what your system likes best
Posted: Tue Aug 21, 2001 1:19 pm
by chaobox99
I think the system is a box, everything is linear, isn't it?
There should be an equation to pinpoint an optimum RWIN value that will give you the optimum performance. May be I just think like a box.......
Does anyone know if there are any other parameters for RWIN beside bandwidth & RTT?
And, can someone tell me what "btw" means
, it's been pondering me for quite a while, I can never figure it out....
Posted: Tue Aug 21, 2001 1:34 pm
by Lobo
Posted: Tue Aug 21, 2001 4:38 pm
by cablenut
Your RWIN is a total factor of your Connection Speed & Latency across your connection.
RWIN Discussion
The end users system really doesn't matter per say, as long it is optimal enough to accept the Internet connection to 100% it should be fine.
Posted: Tue Aug 21, 2001 4:46 pm
by rmrucker
I am not sure if "average" RTT is what you want. I would agrue for "the highest RTT that you are likely to encounter on a recurrent basis". (Yes, I am aware that sounds stupid)!
For example, if you set your RWIN at your Maximum bandwidth * average RTT -- then you are limiting your window size unnecessarily. What if you connect to a site with a high latency/high RTT -- yet the bandwidth is also high??
Then your window will NOT be full during most of the transmission. A larger RWIN would allow you to maintain a full window during the entire transmission, and therefore usually a faster transmission.
Unless someone can convince you that the RWIN is "too high" when you use the "highest likely RTT", then I would recommend a RWIN that is GREATER than (Maximum bandwidth * average RTT).
I would use (Maximum bandwidth * "highest likely RTT") as my minimal RWIN. But you will find many opinions...
Posted: Tue Aug 21, 2001 4:59 pm
by cablenut
Yes rmrucker I agree that is why in my post on my discussion board. I picked places where I knew I had many hops too (i.e. german sites, and canadian sites) I then took my Max latency and my Min from that group of sites and averaged them out. I wouldn't suggest finding your RTT from sites where you have little hops too, or your lowest latency too.