Re: Cat 5e or Cat 6 -- shielded or unshielded?

["Graham Howe" <graham@xxxxxxx>]

> 2. CAT5e vs CAT6. I see no need for anything better than CAT5e as
Gigabit
> ethernet will run fine over that if properly installed. Cable
should not be
> subjected to excessive pulling forces during installation, should
not be
> bent round too tight a radius, and should not be subjected to
crushing
> including people putting there muddy boots on it whilst laid out on
the
> floor prior to installation. Termination should be done with the
correct
> tools and the pairs should not be untwisted for more than is
absolutely
> neccessary to terminate on the punchdown.
>
> With regard to mains crossing and separation. There should ALWAYS
be a
> physical barrier eg trunking or at least a 50mm separation between
low
> voltage and mains voltage circuits. Best practice is to keep them
as far
> away as possible particularly when running parallel for long
distances but
> one fact often overlooked it that a mains cable is also
"balanced".
In most
> cases the current flowing down the live is the same as the current
flowing
> back along the neutral and these are flowing in opposite directions
> therefore any interference in that cable effectively cancels out.

Keith is of course absolutely correct, but I thought I'd add my
personal experience of just how tolerant CAT5e appears to be.

As some of you know, my house was not exactly built with structured
cabling in mind, it is 450 years old, built in a 'U' shape going from
3 floors to 2 floors to a single floor. The walls are in places over
2 feet thick and solid stone, there are no cavity walls at all. About
3 years ago I installed 3500m of cable, most of it was CAT5e but
there was also a fair amount of 79 strand speaker wire and CT100
coax. All cable is brought back to patch pannels in the office at the
top of the house and there are 88 RJ45 ports around the house.

I pulled cable wherever I could and it runs alongside mains, hot
water pipes and coax carrying RF for up to 50m runs. At times I was
pulling the cable so hard that the sleeve was burning my hands, in
some places it is bent through more than 90 degrees in a very small
space. Every single cable works perfectly! I have reasonable
performance across my network (although my Scan switches are a
problem) and regularly play ripped DVDs without any compression from
the server in the office along 50m of CAT5 to the PC in the lounge.

I do not have any Gigabit kit, nor am I ever likely to buy any as it
will almost certainly not work fully with my cabling, but streaming
DVDs is as demanding of bandwidth as anything I am likely to do
regularly.

If I were building my own house and could put in cable at first fix,
then I would certainly install it correctly as Keith describes, but I
would still probably stick with CAT5e because I can't see a need for
CAT6. One thing I would strongly recommend though, is to go with
proper structured wiring wherever possible. I use my 88 ports for
everything and often move a phone or a PIR or a computer to another
location knowing that it will work fine once the wires are patched in
the office. I'm not sure I would use CAT5 and certainly not a patch
pannel for wiring that is dedicated to a non-computer function. For
example, if you are going to stick a PIR at a single point, chase out
the wall and bury the wire, then why use CAT5?

Graham