Home Communications Cabling
Overview
568A? 568B? What the?
Cabling systems
Sharing a VCR
or Set Top Unit to multiple TVs.
ADSL Central
Filter
Overview
This basic guide is produced in answer to the many emails I get
concerned with cabling homes for Data and communications, which
is related to my main line of business through OzTechnologies.com
(although I don't get the chance to get out on the tools much
myself these days).
There are a variety of options when it comes to cabling a house,
and several guidelines and industry standards that need to be
followed. Communications Cabling must be carried out by a licensed
Cabler. Penalties can be applied under the Telecommunications
Act for non-compliant cabling or equipment so think twice before
you DIY or trust a newbie to do it for you. Aside from the safety
issues, the last thing you want is to pay to have the whole job
done again because it wasn't done correctly the first time.
I've seen so many bad jobs (eg incorrect/inappropriate materials,
wrong layout, faulty equipment, incorrect terminations and so
on) that it's just not funny any more.
Some things to ask your Cabler -
Does he/she have an ACMA
license and what level is he/she licensed for?
Does he/she have 3rd party property damage cover?
What testing procedure/equipment will be used?
What guarantee is offered?
What experience does he/she have?
Wiring Patch leads
When wiring patch leads a common misconception is that "she'll
be right as long as the colour code matches on both ends".
Whilst this may work over short distances, for the most part nothing
could be further from the truth. I get a lot of work cutting ends
off Cables wired in the incorrect sequence causing slow Network
access, data loss or just plain not working at all.
The unfortunate thing about matching the ends is that the relatively
cheap Pair Testing Meters will usually indicate a thumbs up even
though it's just plain wrong.
The same goes for Keystones (sometimes called mechs). The colour
indicated on the Keystone must be adhered to or you will create
a lot of pain for yourself. The problem with most keystones is
that they are tiny and the little chart drawn onto them is hard
to read as they show two different wiring standards side by side.
568A & 568B.
| 568A Patch lead
With the clip part of the cable end facing away from you,
wires should go in the following order from left to right:-
White/Green - Green, White/Orange - Blue, White/Blue - Orange,
White/Brown - Brown
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| 568B Patch lead
With the clip part of the cable end facing away from you,
wires should go in the following order from left to right:-
White/Orange - Orange, White/Green - Blue, White/Blue -
Green, White/Brown - Brown.
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Ensure that the ends of the wires go all the way into the Clip
so that you can see the ends of the wires against the end of the
plastic, and if you don't have the proper crimping tool, don't
even bother starting.
Note: A crossover Cable uses 568A on one end, and
568B on the other.
Cabling systems
The first diagram below sets out the cheapest and most common
way to cable a home or small office.
The telephones are wired in a "peer to peer"
type sequence, so that if one rings, they all ring at the same
time, and several people can talk on the same call at the same
time. There are handsets available that allow a call to be transferred
from one handset to another, and can also double as an intercom.
 If an alarm
system that utilises a "mode 3" socket is to be installed,
then the mode 3 socket needs to be the first one in the series
after it enters the premises, and that's where the main control
panel for the Alarm will go too.
The data points are in a "star configuration"
(all branch out from a central point). This allows a desktop hub
to be fitted to allow all the PCs to be Networked together and
the Internet shared from either a server PC or a small router.
The Cable TV points are "star wired" from the
box outside at the Telephone Lead-in point as per Telstra/Optus
specifications.
If you're pre-wiring a new home, these rules must be followed
for Cable TV wiring.
A minimum of RG6 tri-shield Coaxial Cable with a solid dielectric
core must be used.*
The Cable TV Wiring must be run as per the diagram
to a point on the outside wall higher than 1 metre, but lower
than 2.4. (About chest height is ideal).
The side of the house you choose to run the cables to will
obviously be the one closest to the Telstra pit, or the tap
up the pole. Find where the phone and cable TV cables are in
your street and visualise how they'll get from there to your
house.
The splitter for all of the outlets must go in the
box outside the house (unless you're in a unit)
Terminations must be of the "F" Connector
type and torqued to specifications.
Any more than 3 active points will require installation of
an Amplifier at around $300.00
Anything outside of these rules, and the Cable TV installer will
be forced to rewire the whole lot, and your money and effort pre-wiring
will have been wasted.
Bear in mind that the Cable Networks are "sealed" networks
and the Communications Carrier (Telstra, Optus etc) in fact own
everything up to every socket and device (STU, Modem etc) and
are not obligated to connect you to their network if your wiring
is considered outside their specifications. The advantage in Pre-wiring
for Cable TV on a new home, is that you don't have to compromise
where the points will be and the Cabling will be properly hidden
from view.
*Update: Previously I had dual-shield co-ax
as a minimum (which was what it was when I was in the game) but
I have received a report form a very reliable source that Telstra
now require a minimum of Tri-Shielded co-ax cable while Optus
& Telstra Satellite require Quad-Shield. It may be well worthwhile
to check with your Cable provider before you fork out for the
wrong cable.
The diagram below shows the next step from a standard Cable job
on a home or small office.
In this situation we are installing a small PABX (Commander type
Phone System), and a patch panel for all the Data and Phone
sockets.
The main advantage here is that we can swap and change patch
leads to our heart's content down the track without having to
rewire anything, and all of the Networking Hardware and the Cable
modem is hidden from view in a cupboard.
You'll notice that now the telephones are now wired in
a "star configuration", and the PABX System and patch
panel will be mounted inside a cupboard, out of sight. We will
also be using Cat5E (Data Cable) for the Phones instead of the
standard "2 pair" Phone line. This will increase the
flexibility of the whole Cable installation and allow greater
scope for changes via the Patch Panel.
The data points are still in a "star configuration",
however now we have the central point in the cupboard where we
will also install the Cable modem and a small Router
to share the Internet Connection and Network the PCs together.
The advantage of a Router over a hub is that it doesn't rely on
a PC to be "always on" to share the Internet to all
the other PCs.
The Cable TV points are "star wired" from the
box outside at the Telephone Lead-in point as per Telstra/Optus
specifications mentioned above.
Ensure the
cupboard has louvered doors or some other method to allow air
circulation. Excessive heat and Networking Hardware don't mix
well...
A PABX system has many advantages over the standard method of
wiring for Phones. Features like having an internal intercom,
having several lines available at each handset and even being
able to answer the doorbell or unlock gates are available with
most PABX systems.
Expect to pay somewhere from about $1500.00 for a basic new system,
depending on the number of handsets and features required.
I installed a basic Aristel System
with two lines and four handsets, music on hold etc, Netgear JFS516
16 port Switch and patch panel on a mini rack/swing plate
in my home office for around $2000.00. This doesn't take into
account cabling or labour, but will give an idea of a starting
point for this type of installation.
Chuck and Emma have a
great Website which details the structured cabling installation
at their new home. Note the double
jumpering on the phone line (blue & white wires) on the
bottom row of the patch panel. This is the method necessary when
no PABX is to be installed (at least in the short term) so that
the (single) phone line can go to multiple points. These can now
be patched to various rooms using patch leads on the other side
of the patch panel (and changed around easily if circumstances
change). On my patch panel,
you'll notice little white cables coming in from underneath. These
come directly from my PABX and I can plug them into any socket
to go to any room or workstation where I have a data point installed.
Naturally I installed dual outlets everywhere so I can have both
a phone and data point active at the same time anywhere I choose.
Note: For those intending to DIY, note that there are legal
requirements for this type of work and they
did receive an unexpected visit from the Australian
Communications Authority to inspect the work and ensure it
was carried out correctly by a licensed cabler.
See my online
shop at OzTechnologies.com
for a selection of suitable Routers & Switches.
Sharing a VCR or Set Top Unit to multiple TVs.
These diagrams show a simple way to change the standard Free
to Air wiring in a house to share a VCR or Cable TV Set Top Unit
to multiple TVs in the home. The drawback with this system is
that although the TVs still maintain independent Free to Air control,
they all have to watch the same Cable TV channel at the same time.
There are infrared relays available that allow the Cable TV or
VCR remote to be used at other TV points by relaying the signal
back to the Set Top Unit or VCR
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ADSL Central Filter
In most situations, the ADSL signal runs down the
same line as an existing analogue service, but there are circumstances
where this is either inconvenient or involves an unnecessary expense
of leasing another line just for the ADSL signal. In other cases,
there may be another service which will not coexist with ADSL
or will adversely affect the ADSL signal.
Normally a small "in-line filter" is installed for each
handset or device that is on the same line as the ADSL service.
These filters prevent the screeching and crackling noise from
the ADSL modem from being heard whilst using the line for voice
and other purposes.
Other situations require that the filter is placed in a central
location before it gets to the other devices. These situations
are -
when the ADSL line is also on a PABX service
where a mode 3 Alarm Socket is present on the ADSL line
where any hardwired devices exist on the ADSL line
where there are more than four sockets in use on a premises
on the ADSL line (This one may be more economics than anything
else, but having too many filters in the system may adversely
affect modem performance.)
A central filter will also get around difficulties with some
phones like many Panasonic Cordless units that don't seem to behave
very well with inline filters.
Image 1: The image below is D-Link's 10SP Central Filter
which is designed for this job rather than the bodgy method shown
in image 2 below that. (The 10SP is installed where the 3 way
join is shown there). The 10SP also has an RJ11 socket so the
ADSL modem can plug straight into it that way if you prefer, which
is very handy for those situations where the incoming phone line
is right next to where the modem is going to live. However, in
most cases a new line will need to be run for a new socket for
the ADSL modem to use and in these cases using the hard wired
terminal is more convenient.
Note: The instructions that come with the 10SP are a little
confusing as they outline a different method for connecting these,
which doesn't seem right to me and isn't the way I'd do it. 
Image 2: The diagram below shows the basic format of wiring
in a central filter. In this diagram I have pictured a bodgy method
using an Alcatel in-line Filter instead of a proper model
designed for the central filter purpose. However, the principle
is exactly the same with the only difference being that a proper
central filter (like the D-Link 10SP above) would go where the
3 way join is shown and none of those 610 sockets would need to
be fitted. I do not recommend or guarantee that this type of filter
will work in these circumstances, but it has been done before
and usually does the trick in a tight spot.
(Click for Larger View)
Free Plug: I can supply & deliver central filters
from my online shop at www.oztechnologies.com.
We have installed heaps of the D-Link
10SP type units and have found them to be great, but we also
have the more recently released Telequip
DSL-004A units available which have been getting great reports.
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