[e2e] TCP Local Area Normal behaviour? any references?

[Cannara]

Jon,

You might check with some of the large storage-systems companies that still
use TCP between fast nodes.  One example here in Silicon Valley, a few years
ago, altered their stacks so the receive window was simply ignored -- they
knew their machines could keep up at 100Mb/s, so the sender just blasted
away.  Sort of like 3Com's NBT for LANs in 1988 -- start out by sending 42
full sized pkts back to back, see what's acked and either continue or throttle
way down (real end-end stuff).

In testing a Gb system here, our lab uses a pretty common PC and a Gb Enet
card to run over 300Mb/s on a LAN with cheap DLink switches (Gb Cu/fiber) --
no bottleneck in the LAN, just at the sender.  Of course our Ixia box can
whack along at a Gb, but again, no Gb LAN bottleneck.

With normal office switched LANs, there certainly will be limits reached in
the matrix and interswitch links, and those are usually spelled out in specs:
either for boxes or chips.  But, that's what backpressure is for.  :]

Alex

Jon Crowcroft wrote:
> 
> this is mainly for educational reasons, not research:
> 
> so i am looking for any papers or dissertations about the typical behaviour of TCP on a LAN - I cannot find
> anything that doesnt include some intermediate device which is a bottleneck, but I 'd love to see a set of
> traces/analyses of a few of today's typical TCP implementations (lets say win98, XP, OSX, bsd, linux and some commercial
> unix server ones) between typical cliens and servers on 10/100 (perhaps gigE)...
> 
> its sort of boring and i guess hard to get published but its quite hard to explain and is the base case when
> starting to teach TCP (and i know there's lots of "corner case" code which means that MTU and window choices may be
> difference ...)
> 
> pointers appreciated...
> 
> j.