TCP window scaling and broken routers
Posted Jul 8, 2004 7:49 UTC (Thu) by ekj
Parent article: TCP window scaling and broken routers
64KB, the max with zero scaling ain't going to be enough for good performance in many situations.
For example, if your ping-time to the destination is 250ms, which is fairly typical for me for accessing US sites from Germany over DSL, then a 64KB window is going to be full if my available bandwith is 2Mbit/s or more. That's not a particularily rare condition.
When downloading from my Uni (which has triple redundant 622MB/s atm-links) the limiting factor is typically the 100Mbit ethernet, at that speed a 64KB window would be full for any transfer where the ping-time is more than 5ms, which is essentially everywhere.
I'm with the kernel-hackers on this one. A router that doesn't handle larger window-sizes properly is broken and needs to be fixed or replaced as soon as possible, anything else will just be band-aids.
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