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J. Clarke[_2_]

In article ,
says...

Cat 6 is what is needed in shielding area. Look it up - it is upgraded.
I added the plenum spec to have a hard wire wrapped and a hard shield
over it. That allows pulling it without snagging it on connectors and
tearing the impedance out of the wire :-)

Martin, there is nothing in the CAT6 or 6A standards that requires a
shield. If you need shielded cable then you use shielded cable. If you
need CAT6 you use CAT6. If you need shielded CAT6 then you use shielded
CAT6.

And when you tell people to "look it up" and don't provide a link you're
being a smartass, not being helpful.

However you may have been duped. Prior to the release of an official
definition of Category 6, many cable manufacturers were selling "CAT6"
cables that met no accepted standard other than CAT5E, and some of those
were shielded.

If you are running 1000BASE-T or less, you need Category 5E. This can
be shielded or unshielded. As long as the installed cable meets the
standard you will get the specified performance, and if the installed
cable doesn't test to standard then odds are that it's an installation
problem that would also degrade the peformance of CAT6 or 6A to the same
level.

If you are running 10G-BASE-T you can get 55 meters out of CAT6 cable or
100 meters out of 6A. Again this can be shielded or unshielded.

You should in general not run plenum cable unless it is required by
code. The jacket is stiffer and it is more difficult to pull--you are
making work for yourself.

And the presence of a steel reinforcing cable is not to allow harder
pulls--if you're pulling harder than accepted installation guidelines
allow odds are that you're kinking the cable, which will degrade it
below spec. The steel reinforcing cable is intended to allow a run to
be suspended.

As for "tearing the impedence out of the wire", impdence is only one of
the specifications that a cable needs to meet to be certified CAT6A.
There's a whole long list and you have to run a $6000 tester on the
cable if you want to be sure that it meets all of them.

The general rule for twisted pair cable is that you don't want to pull
harder than 25 pounds. If you need more than that then the solution is
not to get a bigger hammer, it's to find out what the cable is hung up
on and fix it.

It will certainly do no harm (other than to the budget) to run CAT6A
where CAT5E will suffice, but there's no real purpose served by it
either.

And I would avoid CAT6--it won't run 10G for its full allowed span and
doesn't run 1G any better than 5E so it's wasted money. Go with 5E or
6A.

Also, shielded cable is not a panacea. If the shield is improperly
bonded and terminated then it can introduce noise levels far beyond
anything that unshielded cable is likely to pick up in most
environments.

The current standard (EIA/TIA-568-C) can be obtained from TIA
http://www.tiaonline.org/standards/buy-tia-standards. It's not cheap.

Martin

On 2/5/2012 2:23 PM, David R. Birch wrote:
On 2/5/2012 8:08 AM, Karl Townsend wrote:
On Thu, 2 Feb 2012 12:05:30 -0800, "Steve wrote:

I want to run a hard line Cat 5 out to my shop. It will be inside PVC.
What is the limits of length of Cat 5 before you start running into
problems? I'd estimate it at 150' run.

Steve

The only time I've had a problem with CAT 5 at this length is across our
shop where we're running 2 4kilowatt and one kilowatt LASERs. Lots of
RFI, so I used shielded cable.

David