Data Cabling For Beginners
What is cabling? Cabling is the foundation of your network, it is the medium that connects all your computers and servers together and is probably one of the most important and often overlooked items in business networks. The process begins by installing a twisted pair cable made up of twisted wires surrounded by a protective jacket to connect data lines to a computer or other network component. The cables are run through ceilings and walls, out of sight, and link a data/phone drop to a patch panel, or other termination block often installed within a rack in a server room or telecom closet. Simply put, cabling is used to link together computers so they may form a common network and communicate seamlessly with one another.
Anatomy of a typical cabling installation:
- The cable begins its run from the central termination point or MDF (Main Distribution Frame) and extends through the building to an outlet.
- The outlet is terminated with a keystone jack (RJ-45 jack) rated for the type of cable you are using.
- A patch cable is then used to connect the RJ-45 workstation area outlet (WAO) to a computer or other device network capable device like an VOIP enabled phone.
- In the server room, MDF, or telcom closet, cables are terminated on a patch panel and the corresponding numbers will be aligned to ensure easy identification. A floor or wall mounted rack (typically 19″ wide) may be used to house the patch panel depending on the rooms design and space requirements.
- Finally, cable testing will be done to guarantee everything is in working order, and certification testing may also be done to ensure compliance with industry standards
Once your office is properly cabled, efficiency is sure to increase and any additions or changes to the cabling system will be easy to accomplish. So how do you get started? There are several variables that must be considered before you begin. The first is what type of cable will be used. There are various cable types and using the correct one is critical. As technology advances, cable protocols are becoming faster and better.
- CAT3 – An unshielded twisted pair (UTP) configured to carry data up to 10 Mbit/s, with an attainable bandwidth of 16 MHz. Popular in the early 1990’s but now considered obsolete, it decreased in popularity due to the favoring of the high performing CAT5.
- CAT5 – A twisted pair high signal integrity cable that is capable of upholding frequencies up to 100 MHz. Within a category 5 cables are 4 twisted pairs in a single cable jacket. This use of balanced lines helps keep a high signal to noise ratio and considerably reduces crosstalk interference.
- CAT5e – An improved version of Cat 5 that increases specifications for far end crosstalk and all new installation should be at least CAT5e
- CAT6 – A cable structure for gigabit Ethernet and additional network protocol that is backwards compatible with CAT3, CAT5, and CAT5e. CAT6 features stricter blueprints for crosstalk and system noise. CAT6 provides performance up to 250 MHz.
- CAT6a – An improvement on CAT6, CAT6a operates at frequencies up to 500 MHz and can carry 10 Gbit/s operations up to a maximum distance of 100 meters. CAT6a also improved conditions particularly in the area of crosstalk.
- CAT7 – Backwards compatible with CAT5 and CAT6. CAT7 introduces even more exacting specifications for crosstalk CAT6 or CAT6a. Shielding has been added for individual wire pairs, and the cable as a whole to achieve this. CAT7 has been created to allow 10 – gigabit Ethernet over 100 meters of copper cabling, and is capable of running at frequencies up to 600 MHz.
After you have selected your cable speed requirements you have to determine with jacket type is required for your particular installation:
- Plenum – Plenum is a type of cable jacket that is not only extremely fire resistant, but also emits a far less toxic smoke should it catch fire. Some buildings and building codes require this as a precautionary measure in case of fire. The name plenum refers to the air conditioning, HVAC systems installed in buildings used to pull air out of once area and blow it out at another. If there happened to be toxic smoke in the air, imagine how quickly it could be pumped throughout an office building with some of these large suction systems in use. With plenum jacketing, toxicity levels after a catastrophic event like that would be exceedingly lower than with PVC, however plenum can be almost twice as expensive as standard PVC.
- PVC – PVC is standard a standard cable jacket that is exceedingly cost effective if you are on a tight budget. Although not as safe as plenum jacketing, PVC works at the same speed and is the same quality of cable. The only difference, other than the cost would be that the PVC jacket material is extremely toxic when burned. For standard home use, PVC might not be a bad choice, but for a populated business office, or a large public facility such as a hospital or a library, PVC would be a recipe for disaster due to the combination of HVAC systems and high number of people that would be exposed to the toxic fumes.
Another important factor to consider is what type of ceiling you have in your building. This will directly affect how the cabling will be installed.
- Drop Ceiling – with a drop ceiling, cabling is as easy as sliding a ceiling tile open and running the cable through. This type of ceiling allows for the cables to be easily hidden and is the least difficult to work with and is dominant ceiling type in most commercial buildings.
- Open Ceiling – an open ceiling requires meticulous attention to detail being that the cables and beams will be exposed and time must be spent to make the cabling aesthetically pleasing.
- Hard Ceiling – If you have a hard ceiling, the cabling job will be the most difficult. Cabling a hard ceiling is far more work than cabling a drop ceiling, which makes for a more expensive and time consuming job. Few commercial buildings have hard ceilings, but nearly all residences do.