[TAG] Wiring a house with ethernet
rick at linuxmafia.com
Thu Oct 13 11:56:37 MSD 2005
Quoting Jason Creighton (jcreigh at gmail.com):
> Non-Linux hardware question here regarding wiring a new house with for
> ethernet with Cat5e cable, which I've never done before, so I'm trying
> to be paranoid about it so I don't get anything wrong.
If you haven't yet bought your 1000' spool, go ahead and spring for
Cat6, instead. One of the most common judgement errors in cabling a
location is to save a minuscule amount of money buying for today's
standard, instead of the standard of five years from now. Even really
good cable costs very little, especially compared with the cost of
Another common judgement error is to pull only as many cable runs as you
need. Smarter is to run about four times as many cables as you need to
each location. You do it once, four are about as easy to pull as one,
and (again) cable is really quite cheap.
Disclaimer: I haven't had to cable or recable a site in quite a few
years. Therefore, I am probably missing a few tricks. Also, there are
_other_ mistakes I would probably tend to avoid out of habit, and might
never think to enumerate to others. A few, I would be able to remember
and list, like staying away from fluorescent light ballasts and any type
of electric motor and AC cabling thereof (classic office-building
example: elevator shafts), and I might even be able to remember the
minimum radius for any cable turns, but I'm going to omit a lot of other
> The concept I have in my mind is to run a bunch of wire to different
> parts of the house from a central location (probably a closet or
> something), crimp standard male RJ45 connectors onto one end and plug it
> into a hub/switch and wire the other end into a female RJ45 jack at the
> other end (bedroom or some other living space) in a nice little outlet
> box, possibly having a phone (RJ11?) jack in the same outlet box, if
> it's a location that needs phone as well.
Depending on local prospects for inexpensive network parts, you might
include a patch panel in your design, for the network closet. It's
where you would terminate the cable runs. You would then use regular
patch cords to the nearby switch/hub. Lots of reasons why you should
prefer that if feasible, including avoiding damage or lossage to the
cable runs over time, as you reuse/rearrange things.
It also is more foolproof: Consistently crimping RJ45 cabel ends
correctly is something that comes only with practice, and getting it
wrong is both very easy and can be really problematic to find.
If you're going to do the cabling job yourself, find a friend who has
the _real_ professional-quality tools, e.g., toner, inductive amplifier,
and crimper. The canonical telco-grade choices are the ones from Ideal
Industries (toner and inductive amp) and Crimpmaster (crimper). And
yes, I do own those. ;->
> Can you run the ethernet cables in the same holes where you've got Romex
> carrying AC, or is there too much interference?
1. You have _Romex_ runs? I hope those are within the AC boxes only,
or within grounded metal conduits, or my guess is that you're very much
out fo compliance with building code. ;->
2. You can run the _ends_ of your ethernet cable close to AC components
without harm, but always keep the runs _proper_ far away from AC (other
than AC contained within grounded conduit).
> How about with the Cat5 you've got carrying telephone service? Heck,
> what about *other* ethernet cables?
I've never heard of problems from either of those situations.
> Which pin-out standard should I use, 568A or 568B?
I don't know offhand of a reason to pick one of the other. Personally,
I just pick one or the other each time -- and stick with that on both
ends (unless making a crossover cable).
> Making ethernet cables is new to me as well. I went out a bought a
> crimper last weekend, and made a little test cable, which *seems* to
> work fine. Are there subtle ways you can get it wrong that will haunt me
Yes -- and one way is to buy a cheap, commonly available crimper. ;->
> Is there some easy way to test this stuff without having two laptops at
> the jobsite?
There are dedicated cable-tester gadgets you can buy. They cost.
Last time I supervised the cabling of an office -- when my then-employer
moved in 1989 -- I did it with a server on one end and a laptop on the
other. As the cabling contractors declared each cubicle ready, I would
be right there to say "Sorry, you screwed up. Do it again." They
really hated me.
If I root around, I can probably find some online guidelines that need
to be met for an installation to be properly within, say, Cat5e spec.
That's where things like turning radius and maximum length are covered.
You might want to look for those, too.
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