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We get a lot of mail about carrying LAN and telephony on the same cables. This page is designed to give you some information to let YOU decide whether you want to do this or not. It is not easy and you should be very comfortable with all the information before you set out to destroy your premises wiring!
This is not an activity to undertake between TV shows but may, depending on your current knowledge, require some serious effort and may (heaven forfend) REQUIRE YOU TO THINK. You have been warned.
If you mix LAN and Telephony on the same wiring it will be non-standard. Put simply this means that you may not be able to take advantage of certain new applications that use the currently unused pairs in 100base-TX. Increasingly we are seeing 'Power-over-Ethernet (PoE)' systems which can make use of both spare pairs in 1000base-TX wiring and will likely provide power for VoIP or other technologies. If you mix PoE systems with non-standard wiring you could destroy or damage equipment and have other unpleasant or harmful effects. 1000base-T (gigabit Ethernet) uses all 4 pairs (8 conductors) and cannot be used with mixed LAN and telephony wiring.
DISCLAIMER: THE INFORMATION PRESENTED HERE IS NOT WARRANTED IN ANY WAY. PROCEED AT YOUR OWN RISK. NON-STANDARD WIRING MAY HAVE UNINTENDED OR HARMFUL CONSEQUENCES BOTH NOW AND IN THE FUTURE.
Electricity and Telephone Wiring: When the telephone rings and depending on how close you are to the central office there may be a serious voltage (up to 150 volts) on the line. Take sensible precautions such as:
Many newer home and office cable installations use category 5 or 5e wiring. In many cases this carries just telephony or LAN traffic. We are asked whether it can carry both LAN and Telephony since pulling additional wires can be a difficult, messy, expensive or downright impossible.
Since 10base-T or 100base-TX wiring uses 2 pairs (4 wires) and each analog phone connection uses a single pair (2 wires) you can, subject to limitations, run 2 telephone connections and LAN traffic on category 5(e) wiring but IF AND ONLY IF YOU CAN ANSWER YES TO ALL THE ITEMS BELOW.
If you are NOT positive about the answers to the above STOP NOW and either find the definitive answers or take-up origami.
Note: If you are doing the wiring - pull two separate wires (one to carry telephony and one to carry LAN - both should be cat 5, 5e or 6) to a single multi-use jack. This will save a lot of hassle. Only use these techniques if you have no other choice.
Another Note: If you ARE doing the wiring consider pulling a good quality video cable at the same time e.g. RG6 or similar even if you have no immediate plans for its use - or then again you may enjoy crawling around in your attic up to your nose in dust and want to do it again. The keystone wall plates described below typically have video outlet key inserts.
OK you are still hanging in there - or perhaps this is more interesting than Origami (just who is this Origami person!).
You want this stuff to last. Right? You never want to touch this stuff again. Right? You want to do other things with your life. Right? You never want to crawl around your attic and basement again. Right? DO IT ONCE AND DO IT RIGHT. EVEN IF YOU HAVE TO MISS TWO TV SHOWS INSTEAD OF THE ONE THAT YOU PLANNED.
These notes assume that you want one or more LAN connections and that you want to carry both telephony and LAN on the same cables.
If you thought this was going to be easy - forget it - go take-up floral arrangements, golf or watch paint dry.
Before you start you need to do three things
Invest in (or borrow) the right tools. You will need as a minimum:
A punch down tool (for the wall jacks and any cross-connects).
Labels for marking both ends of each connection/cable if this has not already been done.
If your cabling is not numbered (or otherwise clearly identified) or you are suspicious you may need cable detection equipment. This equipment normally has two parts. One part injects a tone onto a wire and the other end is like a wand and allows you to find the end that is carrying the tone. This type of equipment can vary enormously in price and quality ($100 to $500).
If you have to make up LAN or Telephone end cables then you will need a crimp tool suitable for RJ45 (8 wire - 4 pair) and RJ111/12 (6 wire) connectors. Get the best one you can afford. They typically come with a built-in cable-cutter and wire-stripper. Make a few practice cables and test them until you get it right - its harder than it looks.
If you are pulling the cable - espcially in tight spots - get what is typically called a cable fisher. It's a roll of spring steel with a hook at the end for pushing and pulling wire. Indispensable.
Make a sketch plan of your current wiring and note the colours used at both ends of each connection, equipment connected etc. and allocate, if it is has not already been done, a unique ID or number to each connection and then label both ends of the cable - as soon as you have found both ends of it! Remember you don't want to do this again.
Finding both ends of any single cable run is no easy task and you may need to use cable detection equipment to do so (see above). MAKE NO ASSUMPTIONS. Someone else, far less skilled than you, may have already installed non-standard features.
Document your new design on a new sketch plan, because:
In three days time YOU will have forgotten what you did.
You may sell or move from your premises and its pretty unfriendly, if not dangerous, to leave your non-standard wiring undocumented.
Your design should cover as a minimum the following elements:
YOUR COLOUR CODING STANDARD. Start with the LAN and select either 568A or 568B colour coding. This scheme defines the 2 pairs (4 wires) for the LAN. Select one spare pair to carry the first Telephony connection and the final pair to carry the second telephony connection. Stick to this standard everywhere EVEN IF IT MEANS RE-WIRING EXISTING CONNECTIONS. The alternate is that you will have non-non-standard wiring. Not even your mother will be able to help clean up that mess.
The following is an example of such an allocation (based on 568B color coding) but it is not the only one possible.
| Pin No. | strand color | Name |
| 1 | white and orange | LAN (TX_D1+) |
| 2 | orange | LAN (TX_D1-) |
| 3 | white and green | LAN (RX_D2+) |
| 4 | blue | Telephone 1 |
| 5 | white and blue | Telephone 1 |
| 6 | green | LAN (RX_D2-) |
| 7 | white and brown | Telephone 2 |
| 8 | brown | Telephone 2 |
All the access points/jacks, to include the new ones you are installing, the connections to be supported e.g. kitchen - 2 telephones, den - 2 telephones and LAN etc., etc..
It's important that you understand the concept of Star Wiring topology (sometimes called home-run wiring) before you start. All LAN wiring uses a star topology.
Star (or home-run) wiring means that each access point (wall-plate) is directly run back to a central or home location (normally in the basement or where the telephone service enters the premises) with no breaks. Many, if not most older premises, and even quite recent ones use multi-drop telephone wiring which allows multiple phone access points on a single cable run.
This is perfectly permissible for phone systems (typically up to 5 such drops can be used) but, MULTI-DROP WIRING CANNOT SUPPORT LAN TRAFFIC. YOU MUST HAVE STAR WIRING TO EACH ACCESS POINT THAT WILL CARRY LAN TRAFFIC.

This section provides some notes about what type of cables and connectors you can use.
Today (2006) you should be using Category 5e wiring which is typically competitively priced. You can however use category 5 for telephony and 100MB LANS but this may be flaky if you want to upgrade to GB LAN. If you want to invest for the future use Category 6 wiring. It's overkill today but affords a measure of future-proofing.
Cables (5, 5e or 6) comes in two forms. Stranded - each conductor is made up of multiple smaller wires and Solid - each conductor has a single wire. Stranded cable is typically more expensive than solid cable. In general, cables that are rarely moved, such as runs inside walls or backbone wiring use solid cabling. The exception to this is where you need to bend round very tight corners (the bend radius is less than 6 inches or 15cm) in which case you should use stranded cable for this purpose. Any cable which is moved or unplugged frequently, such as PC to wall plate cables, should use stranded cable.
Stranded and solid cables MUST use the appropriate connectors. Do not be tempted to mix them. It is sometimes very difficult to tell from a connector description which is which. In general avoid these connectors because if the supplier does not know - what chance has the poor user. In general, connectors designed for wall plates assume solid cable.
The next item on the agenda is getting the right connections at the room Access Point Wall-Plates (or Jacks - we're going to use the term Access Point from here on (AP for short)).
There is an enormous choice of Access Point wall-plates available today from reputable network suppliers with almost every combination of voice, data and video connections. The most flexible are called keystone wall-plates and provide blank plates with the right number of empty holes (available with typically 1, 2, 3, 4 and 6 holes). Recessed and surface mount options, as well as a whole range of colours, are typically available.


Keystone wall plate examples
Into these 'keystone' holes you plug the keystone jacks of the type that you need e.g. 1 RJ45 (for LAN) and 1 or 2 RJ11/12 (for Telephony), video etc. A wide range of colors is usually available. Both punch-down and 'tool-less' versions are now available.

Keystone jack example - punch-down

Keystone jack example - tool-less
End connections are critical and if poorly done can be a huge source of loss and poor performance. Use high quality and correctly rated connectors. DO NOT BE TEMPTED TO SKIMP COST AND USE EXISTING WALL-PLATES IF THEY ARE NOT SUITABLE JUST BECAUSE THEY ARE THERE. YOU WILL REGRET THIS WITHIN MINUTES. DO IT ONCE AND DO IT RIGHT.
In a Star Network eveything interesting happens at our central or home location which is typically where the telephone wiring enters the home or premises. Here we locate our Hub/Switch and carry out all our cross connections using a Wiring or Punch-down block such as 110 type, BIX or Krone. We show a common 110 type below. They come in all sizes but each 'bar' typically has 25 punch-down slots - each 'bar' will take 3 incoming cables.

The price difference between a Switch and a Hub is almost vanishly small these days. Unless budget really is a key issue we would suggest a Switch. They come in all kinds of sizes 4, 5, 8, 16 and 24 ports. some have the ports at the back and leds at the front, others put both at the front (we illustrate both types below) Note: We show particular vendor products for illustration only. Any suitable Switch or Hub will do the job we do not endorse or recommend any particular vendor product.

RJ45 and LEDS at front

RJ45 at Rear LEDS at front
The general specification - irrespective of whether its a switch or hub - is:
They typically come with lots of other features e.g. Full/Half Duplex, managed or unmanaged - your budget will figure out what else you want or can afford.
We are going to:
This is a big job so spend a couple of minutes reading these notes:
Making good end connections is both the key to success and tougher than it looks. The following notes may help:
Electricity and Telephone Wiring: When the telephone rings and depending on how close you are to the central office there may be a serious voltage (up to 150 volts) on the line. Take sensible precautions such as:
When you are wiring each access point be consistent and methodical. Either label each access point on the front cover (LAN, Telephone 1 etc) or use the same convention everywhere e.g.

If you don't use a connection in a particular room - use a blank insert don't change the position i.e. in EVERY room the second line is the bottom right position or whatever.
We are going terminate our 8 wire (4 pair) cat 5, 5e or 6 wires to the wiring block and then cross connect them to their destinations. Each LAN connection will go to a separate port on a HUB or Switch and the telephone pairs will go to our common telephone line(s). Diagram 2 shows this conceptually:

Diagram 2 - Cross Connect
The following notes and diagrams assume that you are using the proposed color coding scheme. See diagram 3 below showing a single color coded diagram.
Notes:

Run around the house check everything works, rejoice and finish off watching that second TV program you almost missed. Phew!
Pear-shaped is a quaint British expression meaning ... well.. things are not too good.
Regretably there a lot of things that can go wrong - the following notes may help you:
Problems, comments, suggestions, corrections (including broken links) or something to add? Please take the time from a busy life to 'mail us' (at top of screen), the webmaster (below) or info-support at zytrax. You will have a warm inner glow for the rest of the day.
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