Ethernet math (Was Re: MWC's Coherent - A Lemon...)

[Hwa Jin Bae]

In article <2841 at crash.cts.com> jca at pnet01.cts.com (John C. Archambeau) writes:
>Anything can affect the throughput of an ethernet.  If one machine that is
>part of the network chatter is not up to the speed in processing data (i.e. a
>slow ethernet card) then it can and often times will affect the through put of
>the entire network.  Overload the Appletalk/ethernet gateway with a large
>number of Macs telnet'ing into one or more Suns and that will slow things down
>well since the gateway has to service all of these Macs as well as handle all
>of the ethernet traffic going into the Appletalk network.

Duh.  Tell me something new.

Is it just me or are you trying to change the story here?  The story being:

In article <2755 at crash.cts.com> jca at pnet01.cts.com (John C. Archambeau) writes:
> Yes, but that's a quiet ethernet.  What I'm referring to is a real noisy
> ethernet that is being used.
> Let me setup a real network of the order of 10+ machines with varying
> performance on the ethernet and I will bet that the performance will be about
> 3 Mbit per second on a good day.

Where I replied:

Not true at all.  Even with "a real network" I have here with 30+ various sun
workstations (sparcStations, 3/60's, etc.) and servers (plenty of NFS 
traffic), burst throughput performance of around 600 MegBytes/sec can be
sustained without causing meltdowns.  This is using severly hacked version
of 4.3 BSD Tahoe TCP/IP running within our realtime OS on a 16Mhz 68020
VME SBC with an onboard LANCE chip.

Now you say:
>
>The issue is that a lot of things can happen that will make ethernet slower
>than molasses and it can be in either hardware or software.
>
>I've found that from experience that Macs and PC's are the biggest offenders
>to mucking up ethernet throughput.

Duh.  What a revelation!

Which point are you trying to make?

Let me help:

Your point #1: a "real" ethernet with more than 10 machines will have at most
3Mbit/sec performance rate on a good day.   --- My data indicates this is
wrong.  Give me some of your data that proves otherwise.  No rhetorics, please.

Your point #2: Ethernet throughput varies and can be affected by ill-behaved
hosts.  --- What a brilliant analysis!  Gee... I'd have never guessed that.

Do you see a smooth transition from Point #1 to Point #2?  I don't.

This is getting boring, quick.  Enough from me.  Carry on JCA.
-- 
hwajin at daahoud.wrs.com