[ale] microcenter goodies

[Jeff Hubbs]

Well, in a corporate-type environment or anywhere where you're going to
have more than about 32 Ethernet nodes and you actually care about
things going quickly, you need a switch, preferably one that accepts
modules, with a high-speed backplane.  That means that the modules and
the individual ports on each module are able to talk to each other at
far faster than Ethernet or Fast Ethernet speeds.  I've seen Cisco
marketing-speak saying things like "near-wire-speed backplane."

If to handle 240 drops you walk into CompUSA or call CDW or whatever and
buy 11 24-port 10/100 switches, hook 10 up to the office CAT5 wiring and
then hook their uplink ports to the 11th one, it WILL work but it also
WILL suck.  First, those 24-port switches are going to have OK backplane
bandwidth but not great, because they're built to be affordable by the
CompUSA crowd, right?  But what will really bite is that you'll have
machines that have to get through THREE SWITCHES to see each other and
their latencies will naturally accumulate.  You will have spent quite a
bit of money to get crappy quality.  On the other hand, if you get a
really good switch with modules that will take you up to 240 drops and
beyond, everyone will be essentially "in the same room" and everything
will be nice and fast.  

Where I used to work, they had things set up with multiple cheap
switches and they were either all hooked into one switch or actually
daisy-chained to some extent (yuck).  I know that there were a number of
people (me included) who dealt with an insufficient number of drops in a
BRAND NEW OFFICE MEANT FOR SOFTWARE DEVELOPMENT who had several machines
at their desks hooked up to a hub or switch.  This can leave you
frustrated as all get out when you have to push around 200-MB files
around or make use of anything that requires a little bit of network
stress.  

Then again, these are the same people who thought UPSses were
unnecessary because the building had a generator (the one sitting in a
puddle of diesel fuel outside).  Of course, because all they knew was
Windows, there were used to habitually rebooting their servers anyway.

When I worked for the Dept. of Energy, I found all kinds of fault with
the prime contractor's IT operation but their network management was
just about first-rate.  They had big Cabletron modular switches that
took those oblong connectors (the type used for big phone systems)
instead of RJ-45 - just the thing if you're trying to set up several
hundred drops' worth of Ethernet.  They had several of those things
handling the building I worked in and IIRC they joined them with FDDI
(this was so-so as long as we weren't using 100base-T).


On Mon, 2002-06-17 at 16:12, Courtney Thomas wrote:
> Guidance as to what 'proper ethernet concentration' is and how to do it,
> would be appreciated.
> 
> Courtney
> 
> 
> 
> 
> Jeff Hubbs wrote:
> > 
> > On Mon, 2002-06-17 at 18:37, Geoffrey wrote:
> > > Thought I'd let folks know, I picked up a 5 port 10/100 switch at
> > > microcenter yesterday.  Hooked that puppy up and wow, are things moving
> > > better.  I replaced a hub.  This thing really smokes.  It was 19.99.
> > > I've never heard of the company, but it's got a 3 year warranty.  5-port
> > > n-way switch (etherengine 500-s) by gigafast.
> > >
> > > Quite the deal I think.
> > >
> > > --
> > > Until later: Geoffrey         esoteric at 3times25.net
> > 
> > Oh, yeaaaah...if you've been using a 10base-T hub and you've been
> > depending on it for more than just Internet access or calling up small
> > files from a file server, then, yeah, it makes a BIG difference to bring
> > in a 10/100 switch.  I'm routinely pushing around multi-hundred-meg
> > files and if all I had were a 10base-T hub, I'd be dyin', just sitting
> > there watching that collision light...
> > 
> > I've got two switches here at home that are linked with a 100' crossover
> > cable and the two machines we sit at the most as well as the cable-modem
> > firewall are on the upstairs switch and the file server, the machine
> > that I use for high-quality audio capture, and the other machines that I
> > muck about with go on the downstairs switch.  This does make
> > switch-to-switch latency an issue, so if I had a second 100' cable, I'd
> > move the firewall and cable modem downstairs and have two long cables
> > going to each of the upstairs machines, but right now, only have the one
> > cable, so I'm living with it.
> > 
> > My former employer seemed to have an aversion to proper Ethernet
> > concentration; they would only buy 24- or 32-port switches from CDW and
> > cascade them as needed, which really turned to crap when another guy and
> > I tried to set up his IBM RS/6000 with 10GB of Linux/NFS RAID space.
> > 
> > - Jeff
> > 
> > ---
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> 
> -- 
> Naturity:
> 	....in contradistinction to the oxymoronic.... humanity,
>         and as evidenced by the natural mercy of death releasing living
>         beings from the unnaturalness and "inhumanity" of man.



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