RE: Network cabling
Just some notes from my head about the CABLING part.
general, flexible network for many types of traffic (data/tele/...,
all (end) equipment has same connection to network
(like RJ45 connector)
easy to prepare outlets for all workspaces
easy to service and solving problem
easy to document
high production quality
I divide the network into tree nets:
campus net, ie. between buildings
backbone? net, between floors or parts of a building
access net, between backbone access points (wiring closets) and the
end equipment (like a pc)
Cables I use are usually halogen-free stp cat 5 cable for the access
net. Cable length "in the wall" <= 90m, leaving 10m for patch cables.
And same cat 5 cable type or single mode fiber for the backbone/campus
net depending on need.
If you like, you can make redundant paths from access hubs/switches to
distribution switches/routers, and elsewhere, like Cisco recommends
(you might get info at cisco web site).
Induced noises and such (90% of disturbance is from within a building):
place cable ~ 1m/kV from potential disturbance source
like 25cm from a common 240V unshielded power line (>=2kVA load), utf cable
like 5cm - " - shielded power line (<2kVA load), stf cable
some sources are worse, like railroad and some medical equipment
note, the cable screen is of less use against 50-60Hz noises
divide building in protection zones
ALL cables and pipes (like water pipes) must be "guarded" at the zone border
with eg. gas discharge tubes and/or varistors
possible use lightning conductor
use good ground lines (like 25/32 mm2 or bigger) to a good ground sink/source
avoid vertical metal loops
high voltage is most easily induced by lightning that way
note the metal loop can be part network cable, power cable, water pipe
avoid any metal loops in the building, build like a flat star/floor
be gentle with the cable
don't squeeze it
don't bend it with a to small radius
since that might give you points with impedance change which results
in signal reflextions, ie. possible useless link
in cable to connector/panel connection (cat5), untwist cable at most 13mm
connect RJ45 outlet as in:
Basically 1 (in the outlet) goes to 1 (in the panel),
and the cable pairs are use pins 1/2, 3/6, 4/5, 7/8
Above pinout is called EIA/TIA 568B and is used everywhere except in
the other end of a crossed cable (which connects as 1-3, 2-6, 3-1,
4-4, 5-5, 6-2, 7-7, 8-8)
Rent a cable tester to verify installation, connecting to the wrong
pin is not uncommon when you do a lot of them
one wiring closet per floor containign access hubs/switches
from here cables go out in a star fashion to wall outlets forming the
the wiring closets are connected to the buildings "main" closet
where the distributon switches/routers are
this distribution net is also in star fashion (cable wise) with the
main closet in the center
for some demands you can have a second "main closet" with its own
distribution net to the access switches as a backup
this is "more to configure" tough
thoose "main closets" of each building are connected to a "core"
closet to connect buildings with eachother
I.e. a tree design of three levels of star nets with possible redundant
Karl Hammar Aspö Data firstname.lastname@example.org
Lilla Aspö 2340 +46 173 140 57 Networks
S-742 94 Östhammar +46 10 270 26 67 Computers
From: "Antropov Anton" <email@example.com>
Subject: RE: Network cabling
Date: Mon, 12 Nov 2001 12:43:31 +0500
> It is necessary to know more details.
> What speeds?
> What architecture?
> What distances?
> > -----Original Message-----
> > From: Szabo Tamas [mailto:firstname.lastname@example.org]
> > Sent: Monday, November 12, 2001 12:06 PM
> > To: email@example.com
> > Subject: Network cabling
> > Hi!
> > Sorry if it's too offtopic, but I think it's a little related to the
> > list.
> > Please just ignore if not interested.
> > Thanks for understanding...
> > I need to do some network cabling. The problem is that I never did
> > cabling for more then 20 PC's. This will be more then 50 and the network
> > should extend between several buildings so I'm a little frightened. I
> > could order a book but I'm in a big hurry so I have no time to wait for
> > it.
> > Can someone please point me to some online documentation? Something
> > about structured cabling design...
> > Or can someone answer to some basic questions in private(to not bother
> > the list further with this...)?
> > Waiting for any help
> > Thanks,
> > Tamas