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16. What RWIN (TCP Receive Window) value should I use ?

The TCP Receive Window (RWIN) value depends on two main factors:

1. The speed of your internet connection (bandwidth).
2. The maximum anticipated latency on the line (pings).

There is a BDP (bandwidth * delay product) formula that gives the approximate RWIN you should use for a given throughput and latency...

The Analyzer and the Optimizer go a couple of steps further in optimizing RWIN:

3. The recommended values for RWIN are multiple of MSS
4. The recommended numbers use large unscaled RWIN values

After all those calculations, here is a very rough breakdown of the Analyzer recommended values... Assuming land lines (satellite should use larger RWIN values because of the high latency), and 1492 MTU:

511104 -- works for ~8 to ~30 Mbps
255552 -- 2 to 14 Mbps
127776 -- 1 to 5 Mbps
63888 -- works well up to ~2 Mbps.

  User Reviews/Comments:
by branoox - 2007-08-27 07:12
How Do I Change The RWIN Value On Vista.
by anonymous - 2007-10-01 11:11
From what I was reading about vista, you dont. It has an Automatic RWIN feature. It can be read about in great detail from the MS site themselves. Looks like you should probably enable the stuff in vista, that comes with longhorn, the server version, if you are serving files, or concerned about sending at a higher rate.

From what I read though, its automatic!
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