It’s time to get cabled… What now?

Up until now, you’ve connected all your computers, games consoles, and mobile devices to your home network using Wi-Fi and all has been good with the world. Now though you find yourself wanting more from your network. Perhaps now is the time to invest in a good quality wired network (otherwise known as Structured Cabling). If so, you now have two choices: To pay somebody, usually an electrician an obscene amount of money to do it for you, or to break out the tools, follow this guide and do it for yourself. Before we go further, you need to know that this will involve making holes in your walls and some decoration work may be required when you are done. Still reading, let’s get started…

The home entertainment industry is full of snake-oil peddlers pushing 80 quid HDMI cables and 20 quid a meter speaker cable. Yes, I know that’s still considered low-end by some of them, but still. The networking industry doesn’t seem so bad in that there are cheap and expensive versions of the same items, but they aren’t sold as hard. For the avoidance of doubt though, the patch cables that you get off eBay for 99 pence each will work just as well as the ones you buy from PC World for a tenner each. The thing is, networking is one of the areas where you have to do things properly to get the best results, but you don’t have to spend a fortune doing it.

We will be working with two key technologies. Ethernet and Wi-Fi. Wi-Fi is the easiest of the technologies to understand – it’s just radio waves working their way through the walls and ceilings between the access point and the device. The access point connects the Wi-Fi to the Ethernet network. Ethernet needs a little more explanation in order to cover the fundamentals. Ethernet networks are built using Ethernet cable, which comes in various grades. All are point-to-point meaning they must have an active network device such as a Switch, Router, or end device on either end of the link. Cables cannot be daisy chained and must instead be joined using an active device. The maximum length of any cable segment is 100 meters, generally consisting of 90 meters of infrastructure cabling, 10 meters of patch cabling and four cable connectors.

If you want to exceed 100 meters, Ethernet cable isn’t the right choice of technology and you will need to look at Fibre Optic cabling. This isn’t impossible to do, but it is beyond the scope of this tutorial and into the realm of paying a network professional to come and install it. Returning to Ethernet cable, there are three main standards (5e, 6, and 6a) with shielded and unshielded variants of each. The table below shows the maximum distance each type of cable can be used at for a given speed. Shielded cables have one or more foil conductors wrapped around the insulation of the cores. This is designed to be pulled to ground, reducing the impact of electromagnetic interference on the data lines within. Where a large number of network cables are bundled together, the phenomenon of crosstalk is possible which is where signals bleed from one cable to another. Other issues arise when cables are run in close proximity to EM sources such as florescent lighting ballasts and high voltage cabling. While the design of Ethernet cabling filters out a lot of interference, in hostile environments, the shielding can still make a difference.

Category 10Mbps 100Mbps 1Gbps 10Gbps
5e 100M 100M 100M 30M (*)
6 100M 100M 100M 55M (*)
6a 100M 100M 100M 100M

(*) While it is possible to run 10Gbps network links over Cat5e or Cat6 copper, the maximum length of the link is reduced in order to preserve signal integrity. 10Gbps over Cat5e is not recommended, especially if mission-critical networks will be run over it (If you can’t tolerate issues with the network.) In these cases, using shielded cable to reduce interference would be a worthwhile investment.

STOP

This guide assumes that you are running network cabling within a house or office with a single mains power supply (electric meter and distribution board.) If this is not the case, and you do not understand what follows, do not attempt to perform an installation yourself, and instead consult a professional. Where two segments of the network are connected to separate electrical supplies, specifically the protective earth, if the earths are at different potentials then a current flow may occur over the link. At best this can result in interference being transferred to the data cables. At worst it can result in normally safe cables and equipment becoming live. This represents an electrocution risk. Where a ground voltage difference exists between two network segments, electrical isolation is achieved through the use of a Fibre Optic Link. Again, consult a professional.

Now, if you are satisfied that you can install your network, let’s begin the design process. First of all, you need to work out how many network ports you need and where. We’ll use the house below as the worked example for the remainder of this tutorial. We have three bedrooms, kitchen/diner, living room, and an office in the garden (With power supplied from the house.)

The following equipment needs to be connected. As part of this install, the existing network equipment will be replaced:

  • BT Infinity Type broadband connection for home using BT supplied Modem and own router
  • ADSL broadband connection for office use using own router
  • Home Cinema setup in living room with five network connections
  • All-in-One PC in kitchen for TV/Media
  • Home media server
  • Home Wi-Fi Access Point
  • Home Multifunction Networked Printer
  • Two PCs in bedrooms and One Games Console
  • Two Office PCs
  • Office Wi-Fi Point
  • Office Multifunction Networked Printer
  • Telephone extension from house to office

Given the number of devices to be attached to the network, the best cabling solution is to use a 19 inch patch panel in a rack enclosure. Where the number of ports is smaller (less than four links in any given cable run) then it may be easier to terminate each end of the fixed cabling into a faceplate. Once you are dealing with more than four links, or multiple cable runs, then moving to a system of patch panels is the tidier solution. Additionally, the cost per port of a patch panel is significantly cheaper than that of a faceplate and modules. Eight Cat6 ports in two faceplates costs over £17+VAT while a 24 port Cat6 patch panel can be had for under £14. When using 19 inch equipment, it is best installed in a 19 inch rack, however for our example, given that we will be installing a pair of servers and will have cabling to be hidden, the use of a rack is a necessary addition

The next step is mapping out where we need ports. Generally the switches and patch panels to which these ports connect come in either 24 or 48 port varieties, and cabling is relatively cheap compared to adding in additional downstream switches. Therefore with something like the living room, it can be cheaper to run five cables to the central switch, rather than running a single cable and hanging an 8-port one off that cable. This job is generally something you will only want to do once, so try to add in more sockets than you need right now. It’s easier to add them and not need them than to have to add extras later. We are also running cables outside, which poses additional challenges. Whatever you do, don’t be tempted to just bury an Ethernet cable, they’re really not meant for it and you’re going to end up having to replace it. If the cable is going to be buried, as our ones to the office are, then you have two options depending on the risk of cable damage. The first, if the risk of damage is low is to run standard, high-quality Ethernet cable through a plastic conduit when it is outside the house. If there is a greater risk of damage to the cable, then you can get SWA Ethernet cable which is an Ethernet cable wrapped with steel armour. This is however expensive at over two pounds per meter which, if you are requiring numerous long runs, can cost more than the rest of the network. In this case, the best option may be to return to conduit, but bury it deeper.

Below is the house with where the ports are needed marked out. The ports are located where the equipment is to be placed and additional information is provided about what parts of the decor can be changed. This is important as it determines how the network cables are routed for minimum disruption. The telephone points are located in the hallway, along with the printer. It has been decided that the two servers plus the network equipment and Wi-Fi point will be located in a cupboard within the kitchen. The home entertainment system is located at the front-left corner of the house. The kitchen PC will be located on the back wall of the house. The network connections to the bedrooms will be on the internal wall between the two. The office connections will run under the garden and to the side wall of the office.

If we count up the number of ports we now have and work out where they will be connected, we can size our network up, allowing us to choose the right size equipment. We also calculate the length of the links since this allows us to work out how much cable we will need to use. It is worth over-calculating the length of the cable by a small amount. This means that the cables will have some slack at the termination points to work with and will allow the cable to be reterminated if the connection to the patch panel or the faceplate is faulty.

Link From Link To Patch Ports Switch Ports Link Length (M)
Router Switch 1 0
Telephone Point Patch Panel 1 12
VDSL Modem Router 1 12
ADSL Filter Office Telephone 1 17
Switch Office (1) 1 1 17
Switch Office (2) 1 1 17
Switch Office (3) 1 1 17
Switch Office (4) 1 1 17
Switch Printer 1 1 12
Switch Wi-Fi 1 0
Switch Kitchen PC 1 1 10
Switch Bedroom 1 (1) 1 1 5
Switch Bedroom 1 (2) 1 1 5
Switch Bedroom 2 (1) 1 1 5
Switch Home Cinema (1) 1 1 8
Switch Home Cinema (2) 1 1 8
Switch Home Cinema (3) 1 1 8
Switch Home Cinema (4) 1 1 8
Switch Home Cinema (5) 1 1 8
Switch Home Server 1 0
Switch Office Server 1 0
Total 17 18 186

Our list of ports comes to 17 at the patch panel and 18 at the switch. This means that we would have to aggregate some of the links to get down to a 16 port switch, or use a 24 port switch to maintain the current configuration. The cost difference between the 16 and 24 port switches is minimal, as is the difference between 16 and 24 port patch panels. Given this, it makes sense to use 24 port equipment rather than aggregating links. This means we now have 6 spare ports at the switch and 7 at the patch panel. We can therefore consider adding some additional ports, remembering that it’s easier to add them now than later. If we add some spare links we get:

Link From Link To Patch Ports Switch Ports Link Length (M)
Switch Office Spare (Telephone) 1 17
Switch Office Spare (Home Network) 1 1 17
Switch Office Spare (Office Network) 1 1 17
Switch Kitchen Spare 1 1 10
Switch Bedroom 2 (2) 1 1 8
Switch Bedroom 3 (1) 1 1 16
Switch Home Cinema Spare 1 1 8
Total 7 6 93

With regards to speed, we want to stream media over the network, and again, given that the cost difference between 100Mbps and 1Gbps is relatively small, it makes sense to install a Gigabit network. Currently, the cost of 10Gbps is prohibitive, such that, unless access to large files on SSDs over the network is needed, then it does not make economic sense to deploy it. For the cable, we will use solid cored, copper unshielded Cat6 cable. We do not need to worry about outdoor grade cable since all of our cables will be within ducts when running outside. The cable supplier that I use has this cable available for £87 per 305M drum. The total length of the cable in our installation is 279 meters, meaning we can comfortably install it using a single drum of cable. If we had marginally exceeded the length of a single drum of cable, then it would make more sense to remove one of the spare links than to purchase a second drum of cable. The cable running through the garden is unlikely to be damaged, so we do not need to worry about the expense of armoured Ethernet cable, and will instead run the cable within conduit. Our planned installation looks like this:

To recap where we are at present. We have worked out what the network to be installed will look like, what equipment we will need and where things will be located. The next position is to prepare for the installation. There are three areas we need to look at: Conduits, Wall and Ceiling cabling, and cable termination.

Conduit Cabling

Solid core infrastructure Ethernet cabling is relatively fragile. Unlike mains power cable which can be badly abused and continue to function, Ethernet cable is easily damaged. Because the Ethernet standard sends digital data at such high frequencies – hundreds of megahertz – the cable has to be specially constructed to ensure that the signal gets through intact. Repeated bending of the cable can snap the internal cores. Bending the cable too tightly can introduce interference. Damaging the copper in the conductor can degrade the signal (Because at very high frequencies, skin effect means the signal travels over the surface of the conductor.) It is therefore recommended that the cable be protected from damage and never bent tighter than 4 times its outside diameter. Therefore a cable with an outside diameter of 7mm should be bent through a radius no smaller than 28mm.

I always install Ethernet cables outside in solid PVC conduit. Electrical conduit is generally available in 20mm and 25mm diameters and there are a wide range of fittings available. A 20mm conduit will accept three Cat5e UTP cables (Unshielded) or two Cat6 FTP (Shielded) cables. A 25mm conduit will accept five Cat5e cables or four Cat6 cables. Because the space is limited, the conduit will need to be assembled around the cable. This means that a suitable length of cable is run, then the conduit is slipped over the cable and secured.

When working with a larger number of cables, we can move onto using PVC drain pipes which are available in 32mm and 40mm diameters with a range of fittings available. These should easily accommodate 10+ cables. If you need to run even more cables, the largest readily available PVC pipe is 110mm underground drain pipe. This should accommodate dozens of cables. Once working with this number of cables, assembling the conduit around the cable becomes impractical. The alternative solution is therefore to run in draw wires. Draw wire is 6mm nylon rope which can be purchased in drums of various sizes (500 meters costs around £25 per drum.) The installation process using draw wires is shown below. You will need as many draw wires as bundles of cables that are being used. If you need to install 10 cables, one at a time then you will need 10 draw wires. If you can install the cables two at a time, then you will only need 5 draw wires. Don’t try pulling twenty cables at a time however since the friction will likely be too great to successfully pull all the wires through. Also, don’t try installing the conduit around the draw wires, if they get tangled around each other then you will be unable to pull cables with them.

The conduit should be brought through the wall, this avoids cables getting damaged while coming through the wall void. The following diagram shows how a 20mm conduit system is brought through an exterior wall into the property. Once the cables are inside the property, follow the section on wall and ceiling wiring to secure them. The important thing here is protecting the cable from damage and ensuring that the installation is watertight to prevent damp from entering the property. Where the conduit is being placed underground, it should be bedded into and then covered with a layer of 10mm gravel to help protect the conduit from damage. Where future mechanical damage to the conduit is unlikely it can be buried 300mm under the surface. Where mechanical damage is more likely (under a garden that is regularly dug for instance) then the cable should be buried 600mm or deeper.

Wall and Ceiling Cabling

When a cable is not enclosed in conduit, then cable tray should be used to secure the cable. An example of how cable tray is used is show below. When cable tray is used, the same rules about not bending the cable excessively apply. The cables should also be attached neatly and spread out over the available space on the cable tray. Cable ties should be used to secure the Ethernet cables to the tray, but care should be taken not to over tighten them which can damage the cable. In some cases it is not practical to use a cable tray, such as where an Ethernet cable needs to be attached to a skirting board. In these cases, the appropriate size cable clip should be used. Cables must never be stapled or loop nailed to the wall. When using cable tray, sharp joints, and locations where cables enter and exit the tray should be covered with adhesive foam tape to prevent damage to the cable.

When retrofitting a property with a wired network, a key objective is often to do so, causing as little damage to the decor as possible. This precludes the installation of conduit within the wall voids. In this case, it is acceptable to drop down cables without conduit or cable tray provided that a rubber grommet is used on the entry to the void if metal studwork is used and on the entry to the backbox, again if it is metal. Additionally, cables should be kept as short as possible so there is little slack in the void. Finally, having the Ethernet cable running in close proximity to power cables should be avoided. Where the wall is solid, trunking should be used if channelling the wall is to be avoided. If the wall is to be channelled, then conduit must be used. Do not bury cables directly in the wall as this may lead to premature cable failure.

Cable Termination

We are going to cover two types of cable termination: Into a patch panel, and into a faceplate. We’re not going to look at building patch cables, since this is fiddly and really unnecessary given the low cost of buying pre-made ones. One thing that should not be done is attaching RJ45 connectors to a solid-core Ethernet cable. While it is possible to terminate the cable into the connector, the connections can and will fail easily so avoid them. Faceplates are the best way to terminate 1-4 cables outside of a rack cabinet. Faceplates are generally modular, taking standard RJ45 connection modules measuring 25mm wide by 50mm tall. A single faceplate is the same size as a single 13A socket and can contain up to two RJ45 modules. Double faceplates are available taking up to four modules. Larger custom faceplates are sometimes available, but these are expensive and it can actually be cheaper to install multiple faceplates. This is a completed faceplate installation.

The photo shows the faceplate attached to a surface mount box, with the two cables coming in through the conduit. The two modules snap into the faceplate, this installation uses Cat6 modules, but Cat6A and Cat5e modules are also available depending on the installation. The cables are then terminated into the module using a punch down tool. Enough cable should be left to terminate the cable into the module easily, but not so much that the cable has to be folded to fix the faceplate to the wall. A tip for connecting the module to the cable is to have a flat, stable work surface located level with the bottom of the backbox, this means that the cable can be punched down easily without damaging the cable or connector.

Patch panels are wired in much the same way as the faceplates, however all the connectors are in a line, requiring less cabling space and providing a higher port density. The photos below show a Cat6 STP patch panel I did on a previous installation. The cables coming into the patch panel are first secured to the patch panel frame to prevent movement in the cable from interfering with the electrical connections. The next photo shows a close up of one of the connectors banks. You can see that the foil and drain wire for the shielding is clamped under the bracket. The patch panel is then connected to earth. Also notice that the individual cores are left twisted for as much of their length as possible, only untwisting to go into the punch-down connector. This is vital for minimising interferance.

There are two cable layouts for terminating cables – A and B. The two layouts are identical, except that the Orange and Green pairs are swapped. For an infrastructure network, you will use all A or all B terminations. When making a crossover link, then an A-B link is used. My wiring uses the A layout exclusively. Virtually all terminators will have a colour guide. This table is therefore for reference only.

Colour Pin – A Pin – B
&nbsp &nbsp &nbsp 8 8
&nbsp &nbsp &nbsp 7 7
&nbsp &nbsp &nbsp 4 4
&nbsp &nbsp &nbsp 5 5
&nbsp &nbsp &nbsp 2 6
&nbsp &nbsp &nbsp 1 3
&nbsp &nbsp &nbsp 6 2
&nbsp &nbsp &nbsp 3 1

With that, you have everything you need to complete an installation. Here’s a completed rack with neatly tied patch cabling. If you want to see the full story for how this job came together. Check it out at this link here.

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1 Comment

  1. Scarlett Bogdanovich

    This really answered my problem, thank you!

    Reply

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