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If
you only need to test a few cables or if this is a one off job
you may be able to hire one for a week or two relatively cheaply.
Another point is that if you are an IT manager and responsible
for a sites network, the Fluke would be the better option as
it can also perform some Ethernet tests as well, things like
traffic monitoring and I think it also monitors collisions.
Two
jacks per cable?
Q.
Our offices are moving into an existing building which was wired
by the previous owners, or a contractor for them, and their
wiring is one I have never seen before. Each wall outlet has
two data jack which are "sharing" a single UTP cable,
2 pairs to the left jack and the other two pairs to the right
jack. What problems are we likely to encounter with this setup?
Our normal wiring method is one jack one cable.....
A. It sounds like costs were an issue when this building
was cabled, but if it is configured for Ethernet (using pins
1, 2, 3 & 6) it should be OK for 10BaseT. I wouldn't like
to speculate on whether it will run at higher speeds because
that is dependent on the quality of the installation and the
amount of network traffic.
If the installation was originally wired for Token Ring then
it will use pins 3, 4, 5 & 6 which will not work with Ethernet.
Crosstalk could be an issue if the pairs have been split between
outlets and/or between pins on the jack, (pins 1 & 2 should
be a pair and 3 & 6 should be a pair).
I hope this helps, and although it is possible that you will
have no problems, I would strongly advise a rewire. This is
because it will be easier at this time to carry out the work
and, as you move to higher speeds in the future this wiring
configuration will undoubtedly start to cause problems.
Whats
the difference between stranded and solid cabling?
Q. I just found your web site and i thought that it was
very informative, but i could not find any thing on the difference
between stranded and solid cabling, could you tell me what the
difference between them is? (I think stranded is used as patch
leads and solid is used as a connector between the patch panel
and the wall outlet).
A. You are correct, stranded cable is used for patch
leads because it is more flexible than solid copper. The solid
cable is used in the fixed part of the installation, ie. the
cable between the patch cabinet and the wall outlets. Solid
cable has better performance characteristics than stranded and
it is cheaper to make.
Q. Thank you for your help, it was very useful. One other
thing you could help me with, is the way that the solid and
stranded cable are wired up different? because i know that you
can get RJ45 plugs for solid and stranded cable (i know how
to wire up stranded cable to a RJ45 plug), if so then how is
the solid cable wired up to the RJ45 plug.
A.
The colour codes are the same for solid and stranded cables,
the difference is in the IDC (insulation displacement connector)
in the RJ45 plug. Because the cores are different the contacts
have to be slightly different to ensure a good contact is made.
Pricing
for a cabling installation?
Q.
I am doing some research and am looking for information on pricing
for a cable installation. For instance do you have a flat rate
per drop installing Cat 5 or fiber or do you charge per feet?
Also what is the going rate for this type of installation including
wall plates and cable. Any information you can give me on this
would be very helpful in my research!
A.
It is normal to price a job on a per drop basis but this
is subject to the numerous other factors involved. These include
the difficulty of the installation (ie. is there a false floor
or ceiling or will it all have to be trunked out!), and the
type of cable and connectors that have been specified (some
systems are more expensive than others).
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