STRUCTURED CABLING

UNDERSTANDING STRUCTURED CABLING IN IRELAND TODAY Author: Lynch Networks. Read time: 14 Mins. Date: 21-Aug-2023.

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FOREWORD: The below information was compiled by Lynch Networks and this is our general guide, written in plain language for people from all walks of life. If you read the full page you will learn about structured cabling networks in Ireland, we promise its worth reading. A point of note is that we are specialists in the installation and support of the systems discussed, which We offer as a professional service. As a technical contractor, we offer consultation, onsite inspection and independent Fluke testing services for existing copper and fibre optic cabling. 

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WHAT IS STRUCTURED CABLING? Firstly, the term consists of two words used together which have become accepted within the industry as the description for copper and fibre optic data cabling, installed in a structured manner which is used for connecting devices. Installations are typically completed to one of the main internationally recognised standards for example; ANSI/TIA-568 or ISO11801. The term structured cabling describes a copper and fibre optic cabling system which is installed in a uniform and standardised way within a premises. The core components are based on a centrally located patch panel, then the cables which link out to the various destination locations which are known as data points. This system can be scaled from one or two individual cables found in a small office up to 10,000 or more cables which could be found in a large office block type building. The idea is everything is managed and structured regardless of the size of the installation. Imagine the opposite term unstructured cabling, which could mean that the cabling has been installed with no structure or constancy, with messy cabling going randomly from one point to another around the building and the data points added on here and there with different non-standard components, random colours and no labelling structure etc. With structured cabling everything is installed in a standardised way with all the cabling travelling back to one or more concentration locations where the IT staff can confidently administer the network with no stress or guesswork. Once installed the structured cabling system will centrally connect devices located in different locations of a building such as desktop computers, printers, phones, security cameras and servers etc. Ethernet is the most common system that operates on this cabling infrastructure but its interesting to note that this system is quite versatile and other systems and services other than Ethernet can operate on it such as powering devices over the cabling which is know as POE (Power Over Ethernet) or for example older systems such as POTS & PSTN which are standard telephone lines coming into a property which can be connected to different locations using the structured cabling. The system is also compatible with older analogue-based telephone systems (PABX), security cameras and more. Just to note, there are also Cat7A and Cat8 standards but these are often more costly to install and generally many organisations will choose fibre optic at that point.  As mentioned above, the system can also carry power which is governed by the AWG (pronounced gauge) of the wires inside the cable being used, this is discussed further later on, but it is important to note at this point that only copper cables in structured cabling can transmit digital, analogue and power. This is because the copper parts all operate using electrons while the fibre optic cables rely on photons to operate. This restricts fibre optic cables to only directly transmitting digital data, they can’t directly transmit power or analogue signals, although it's only fair to mention fibre optics superpower, which is the huge distances and massive bandwidth it can facilitate, which is far superior to copper cable.  WHAT IS THE DIFFERENCE BETWEEN ANALOGUE AND DIGITAL? How can structured cabling run both? The difference between a digital and analogue-based system is that digital devices operate by processing binary code, which is based on 1s and 0s. The programming of the 1s and 0s is called software or coding. Each 1 and 0 of the code is set on a physical transistor which is either in an on or off position. 1 defining on and 0 being off. These work similarly in a way to Morris-code which is based on dots and dashes. In a digital system, the physical transistors are known as hardware due to them being a physical component, but both these software and hardware technologies work together in an intricate way that brings us all the wonderful technology we have available to us today. On the other hand, analogue is a simpler more limited system based on wavelength technology, examples would be the VHS tapes you’d watch a film on back in the day or the music tapes you’d put in an old Sony Walkman, you might remember they didn’t need time to boot up like a modern digital device does, they were just ready to go as there was no code or instructions to run. Both digital and analogue systems can communicate over copper structured cabling as both fundamentally use electrons to operate which the copper cabling will conduct. The amount of bandwidth or data transmission rate available with a structured cabling system will be dictated by the category of cable and components installed. Cat5e, Cat6 and Cat6A specifications are most common. WHAT IS THE DIFFERENCE BETWEEN PASSIVE AND ACTIVE? All data networks are made up of two components which are either considered passive or active. Structured cabling consists only of passive components, meaning it does not require power. Any device for example; a switch or a server is considered active because it requires a power supply to function. 

So going back a little, the term structured cabling is a general reference to LAN (Local area network) cabling that is installed permanently within a premises, the premises could be an office, a factory, a data centre, a school or retail unit and so on. The systems principle structure is the same no matter what the building is designed or used for. 

Buildings can be any size, but structured cabling can facilitate installations of any size. The components should always be installed neatly and well presented and in convenient locations allowing the active devices connectivity back to a concentration point where the building's ICT (Information Communication Technology) equipment operates. 

The devices around a building could be desktop and laptop computers, security cameras, Wi-Fi radios, phones, mobile phones, credit card machines, point of sale tills, network printers, switches & servers, industrial machines, basically any device that can connect to the universal RJ45 connector which is used with structured cabling. The universal connector used on both ends of copper structured cabling systems is known as an RJ45 module or data point and uses 8 pins that are approximately 1mm apart. Each pin connects to one wire, its technical name is 8P8C. This connector is backwards compatible with the smaller 4-pin connector known as RJ11 which is predominantly used for telephones. It’s also possible to use media converters at each end for services such as HDMI and others which can utilise the copper wires in structured cabling. Although the TIA sets out two standards (ANSI/TIA-568-C) TIA 568A and TIA 568B with B standard the most commonly used in Ireland and the UK, both A and B connect each pin directly to the remote corresponding pin, they simply have a different colour arrangement with the green and orange pin pairs interchanged. For example, a patch cable terminated on both ends using 568A will work seamlessly on a permanent link which was terminated on both ends using 568B because both terminations are connecting each pin-to-pin. However, it's best practice that overall, an installation uses only 568A or 568B for standardisation practices. Some folks over the years have stated that the A stands for America and B stands for British but that is not true, America, Ireland and the UK mainly use 568B and mainland Europe most commonly uses 568A. 

In our opinion, structured cabling is the single most important part of any data network. This is because the overall installation is often a major task to install and the system should last for decades of service. For any building that requires a deep retro-fit, such as many of the old Georgian buildings where we have completed projects in Dublin City such as Merrion Square, Hardcourt Street and Leeson Street, most of the effort is taken up with construction-type work with preparation, drilling, lifting floorboards etc and making ways, so its crucial this is all done right before the building is returned to the customer and the cabling goes into service, whether its a simple straight forward job or a more complicated retrofit.

The task of upgrading an organisation to a higher performance of structured cabling is typically a bigger project again due to the removal of existing cabling and then the installation of new cabling. This typically involves downtime or out-of-hours work. It's often wise to simply install the new network cabling side by side and then migrate, and afterwards complete the removal or even leave the old cabling in place which is what many companies do. But the main point is that almost all other equipment can be physically swapped out or upgraded and consider the cabling will probably be in place for several of these active hardware upgrade cycles. For this reason, it's important to do the cabling right the first time around. That’s why testing with a Fluke DSX analyser is critical which our installations do and are also covered with a manufacturer warranty for 25 years from the date of installation.

It is also important to be aware for the building owners or a leaseholder, a correctly and professionally installed data cabling system will add value to a building and help attract and keep clients who require these facilities in place, a Fluke test report to hand can consolidate this and having a copy of the report printed and framed on the back of the comms room door is a great idea.

MAXIMUM CABLE LENGHT & TESTING  Important to note, the maximum length and limitations with copper data cabling. The installed section of the cables whether Cat5e, Cat6 or Cat6A is 90 meters plus two patch cables at each end and this will give you a total maximum allowable length of 100 meters. The installed (permanently into the building) section of the cable is referred to as a permanent link and this has a maximum length of 90m. When testing that these cables are installed correctly, the industry-standard device most commonly used is a hand-held analyser unit that comes in two parts, a main unit and a remote unit that together are called a Fluke Networks, Versiv DSX5000 or DSX8000. The main difference between the two versions is that the DSX5000 is rated for up to Cat7A while the DSX8000 is rated for Cat8. Both these devices interrogate the individual cables, completing the same tests and each test cycle takes up to 10 seconds to complete. For each test, the machine will verify if the cable can perform to its stated capacity of Cat6 for example. This device will complete several tests and one of them will calculate the cable length. This will fail if the cable is any longer than 90m. The DSX also has a built-in oscillator, which can track and trace cables that have been damaged or mislabelled. This is one of the reasons why the DSX is the industry standard for testing commercial networks.

Remember, the boxes of cable, the patch panels and the jacks may all be rated for Cat6A, but unless they have been installed correctly the actual performance could be sub-Cat5e or worse. In some installations that we have been requested to independently test, there has been packet loss on cables that have been apparently tested, so this is why the analyser is critical. After your installation is completed (or if you are moving to a new building), you should request a Fluke test report showing the physical data label numbers which should correlate to the numbers in the report. This way you can see proof that each cable is capable of operating at its rated performance. If an installer is using a basic tester which can cost as little as €50 euro compared to approximately €14,000 for a full Fluke Versiv test kit. The functions on a basic tester are commonly only continuity and wire map. When using these cheap testers, it will show that the wires inside your cables are physically connected to each end and in the right order, but it won’t tell you if they are performing to their rated capacity or if they are within length amongst several other details. One cable, which has passed on the basic tester can still cause problems like packet loss, insertion loss, interference or simply poor performance for the life of the cabling, this will have taxing effects on the active hardware such as switches, as they occupy their own memory and processing resources to handle the errors and re-transmissions. Verification and certification with a Fluke Networks DSX by a company that knows how to set up and operate the machine correctly is one of the most important parts of an installation. It's also good to note that it is possible to retrospectively and independently test existing operating networks that have been installed previously and in situations where the cabling is suspected of causing problems. There is also a secondary level of testing which is for Alien Cross talk which is discussed further on, this is where known good and certified cables which are in a bundle with several other data cables are causing issues by interfering with themselfs!

So, commonly when a new structured cabling installation has been completed within a building and all the labelling and testing is finished with the active hardware connected and the staff are working at their computers, talking on the phone, printing, using WiFi and surfing the internet etc, the system becomes part of an Ethernet network whereby the active hardware and passive cabling both come together and work as one ICT network. The passive and active hardware will be working together in symphony, each active device communicating over the passive copper and fibre optic cabling using either electrons or photons and they will communicate using something called a protocol. One common protocol you may have heard of is TCP/IP which functions by exchanging packets of data over the network. Two of the main functions or operations in this protocol which are depending on the structured cabling operating correctly are the network transport layer which is responsible for physically sending signals over the cabling and just as importantly the transport layer which is responsible for error control. These errors that the protocol is dealing with are created by interference or insertion loss created on your structured cabling. These errors will often result in retransmission requests which can flood your network and in turn use up the RAM and CPU resources in the switches, as well as the other devices like computers, laptops etc. and could result in problems which are either mild such as the internet being slow or working inconsistently or you could have severe issues with lots of packet-loss and services like printing and email simply not reliably working. These issues can often impact a business's staff, day in and day out and who have to deal with the stress and delay which will hit their own output or worse affect a customer or client experience. So remember a basic cable tester used on the network with severe issues like this can show a perfect continuity and wire-map test, this is why the correct analyser is critical. 

WHAT TYPE OF NETWORK CABLE SHOULD I USE? The main components of any copper network cable are A. the outer jacket B. the shielding or lack there of and C. the AWG (Pronounced Gauge) of the wire cores that are inside the cable. 

A. The outer jacket can commonly be duct grade meaning it is used for outdoor projects within a duct, standard PVC which is a budget internal option or LS0H/LSNH which means a low smoke zero halogen cable, this is a fire safety option as the cable will have no halogen which is toxic when burned.
B. The electromagnetic shielding of a cable is made up of either an outer shield around the inside of the cable jacket which creates external protection around all 4 pairs of wires from external interference only. This is written as F/UTP (Foil / un-shielded Twisted Pair) or a foil shield around each of the 4 pairs of internal wires which gives shielding from external interference and also shielding from cross-talk between the pairs themselves, is written as U/FTP (Unshielded / Foil twisted pair). The best cable you can get is based on shielded cables which have both a foil shield and a braid around the outside and another foil shield around the twisted pairs which is written as SF/FTP (Braiding & Foil / Foil twisted pair) The braid gives both electromagnetic and mechanical protection and is better at protecting against medium to low-frequency interference, while a foil shield is better at protecting against higher frequencies. Commonly interference will come from other data cables in the same bundle which are transferring their own data but the cable jacket is too thin to prevent cross-talk from entering into another cable. High-voltage cables, radio and microwave emitting devices can also cause interference. SWA or Steel Wire Armour cable which is designed to be outside without a duct will by its nature have protection from low frequencies because of the steel armour which can be useful for running cables outside which may need to travel alongside high voltage cables, this cable needs to be grounded.

*C. The important topic of gauge or AWG of the wires is covered below in its own paragraph so please keep reading on if you would like to learn more.

As mentioned above the many tender documents we receive from various contractors are 99% of the time based on Cat6 and Cat6A and this makes sense to us because both are rated for 10Gbps with within 55 meters of length while Cat6A is rated at 10Gbps out to 100 meters. Consider a standard 1Gb local network connection on a desktop computer connected to a 1Gb fibre optic internet connection for example, this combination will operate at an excellent level of performance, cloud services, streaming and downloads all work seamlessly even downloading multi-gigabit files. These arrive down in a reasonable amount of time so multiplying this level of performance by 10X is by our consideration a very healthy level of future-proofing. Also consider the fact that a lot of the development currently going on is aimed at compression and efficiency of software not just network bandwidth, which is very important for the bit media providers given the high costs involved in transferring their huge volumes of warehoused data.

Our recommendation for general-purpose networks is Cat6 with a max length of 55 meters or Cat6A shielded for longer runs up to 100m both to have 23AWG cores or thicker and an LZ0H outer jacket for fire improved fire risk safety. A point of note is the non-shielded Cat6A does not require grounding but Shielded Cat6A should be bonded to ground. (Covered under TIA-607-C)

WE RECCOMEND... ALIEN CROSSTALK Testing for alien cross talk is supplementary to standard certification. Your contractor should be able to explain clearly and facilitate this extra level of testing on request which is set out by the TIA and ISP/IEC. Crosstalk is when a loom or a bunch of cables are causing interference to one or more cables in the loom which is referred to as a victim cable. Testing for this is completed with a Fluke Networks DSX remote and main unit which are linked using their side ports and then using the main heads to inject and test a random batch. This gives an extra layer of testing and insight to your cabling. The test requires the termination units that are supplied with a DSX kit, fitted to the remote ends of the two cables getting tested. Other contractors that are renting a DSX often won’t have access to this test but don't be talked out of having this completed if you want to know if your network is vulnerable. If you want every run to be perfect and have confidence in the performance of your network we suggest you have this done.

Any cable that has shielding such as F/UTP or F/FTP, will have protection from crosstalk due to the foil shield. In this situation the test is still required according to Fluke Networks as the alien cross talk test is used as an extended test to check the shielding is correctly functioning even though a standard DSX test can check that your shielding is connecting on both ends. The Alien Cross talk tests are specified as PS ANEXT and PS AACR-F.

Interesting to note, that very few installations are specifying testing for this but there is no text from the TIA stating these tests are optional. 

So the important takeaway from the above information is that devices must be within 90m or 100m total length that the copper cables will travel throughout your premises remembering that risers and routes will often travel in various directions not just directly to where you need and will ideally be less then 55 meters if Cat6. New buildings for the most part are designed to incorporate these limits and they typically facilitate cable routes and containment for the low-voltage structured cabling. However, renovations specifically older buildings like many of the schools around Dublin that were built before data infrastructure became mainstream will often have major problems and require significant labour to retrofit cable routes and containment which is discussed further on. For buildings which require runs exceeding 90m, the solution is to have multiple comms locations within the building and interlink these cabinets which will allow greater range. The range between comms cabinets can be greatly increased with the use of a fibre optic link which can also improve bandwidth of up to 100Gbps and more. Although a Cat6A shielded cable within 100m between cabinets will give you a 10,000Mbps link which is often enough for requirements.

IS WiFi BETTER THAN USING A CABLE? Many folks have asked us over the years “Why doesn’t everyone just use Wi-Fi access points around the premises instead of going to the expense of deploying a full structured cabling system” and the answer is the same, Wi-Fi cannot compete with the reliability that cabling presently offers nor offer its consistent performance or even the security advantages of cables being protected inside of the building. It’s also true that not all devices have a wireless connection. The other fact is that 2.4Ghz and 5Ghz radio channels used in Wi-Fi require maintenance and although there are units that have a third radio for monitoring and maintaining channels, not all do and this contributes to the fact that wireless solutions, comparing the consistent performance of both solutions in the field is presently less than equal to a cabled solution.  *C. POWERING DEVICES OVER ETHERNET (POE) The last topic for discussion is on powering devices over structured cabling. Structured cabling is considered low voltage but the power it can transmit is enough to power some devices over your copper network and it is a fantastic ability, being able to turn on or off devices located down the corridor or out in reception with the click of a mouse button, or even remotely while sitting on a train travelling into work for example. Think of devices which have become unresponsive or need a reboot, you can restart the port and reboot the device without having to physically locate and travel to the location. You also no longer need to install a dedicated power supply now that the network is delivering power, these power sockets are often unsightly and take up valuable space. POE-compatible devices can be phone handsets and conference phones, WiFi radios, CCTV cameras, LED lighting and more. More and more devices are currently being developed to use POE so it's a wise decision to consider this now during your planning stage. Utilising POE (Power Over Ethernet) you can also save on electricity by simply scheduling the power via a compatible network switch to power off specific ports between certain times that you know will not be in use. Over a year and more, the savings can be significant and cover the extra cost of the hardware.  So with POE now being mainstream and becoming more common, it's important to be aware that standard Cat6 cable is made up of 8 copper wires within the cable and will typically contain wires 24AWG in diameter. However, if you compare a 24AWG cable with a 22AWG cable the thicker 22AWG is rated for 60% more load, giving you more than double the power delivery. These thicker cores are in our opinion, a valuable investment considering the cost difference in a 305-meter box of 22AWG over 24AWG cable. Note, that the lower the AWG number identifies thicker cores. It's also important to note that the cable technicians will often spend more time onsite as working with the thicker cores can take longer to manipulate into place and this may mean the final cost will be higher but we feel it's a better choice.  Also note that structured cabling is made up of permanent links as mentioned previously, which use a solid copper core while the patch cables at each end use many small cores (braided cable) which make up the overall girth of the conductor and this is to allow flexibility as the patch cables need to bend and move. The gauge of these cables ranges from 22 AWG to 26 AWG. With everything mentioned previously, We hope you enjoyed our general introduction to data cabling in Ireland and hope that it has improved your knowledge and helped you make better choices when engaging a technical contractor. Each topic discussed will have more information but we hope you now have a good wireframe to build your knowledge on, and remember if you do need help with consultation or installation services, Lynch Networks is a trusted service provider and would be happy to quote on your project. Please see our Contact Us page for details. Thank you again for taking the time to read to the end of our page and we hope it has helped you.