Data centre cabling can be the poor cousin of other, flashier aspects of installation. But cabling can last longer, and cause more problems, than any other component of a data centre. This guide to ten areas of better practice should help you avoid some of the most obvious pitfalls, and improve your cabling practice.
Plan the layout of your racks and cabling ahead of installation - This will help to ensure that your rack layout is cable-friendly, avoiding problems with the cable layout. You need to avoid putting stress on the cables, which means no excessive bundling of cables, and no bends that are tighter than 90°. You also need to avoid running networking cables near power lines or other sources of electromagnetic radiation, as these can interfere with the networking. Keep copper cables away from fibre cables to avoid any risk of damaging the fibre cables.
Provide enough capacity for future growth - Demand on your data centre will only grow over time. Ensure that you plan for this growth, by including extra cabling as spares, and providing space to expand. Buy conduit and cable managers that are larger than your current need, to give expansion room, but also ensure that you have more than enough ports and capacity.
Build in flexibility - Future-proofing also means building in flexibility for components to connect with each other. Ideally, every component in the data centre should be able to connect with every other through a flexible patching system, and through good switching and patch design. Building this in as part of the installation is ideal, as it is much harder to incorporate later.
Specify the right cable for the demands on the network - You will probably need both copper and fibre cables, because both have their different uses. Higher bandwidth cabling should be specified for higher demands, but the cabling specification also needs to consider international standards. This means taking into account a move from 10G towards 40G and 100G systems, and the cabling requirements to meet those standards. Ethernet cables are backwards-compatible, so choosing the most up-to-date option is ideal.
Quality of terminations is crucial to good operations - Quality of terminations is a big issue for patch cables. Buying cheap can cost you dearly later, and is really not worth the grief. Pay a bit more for quality, and make sure that the terminations are fully functional from the start.
A bit of time now getting the cable length right will pay dividends later - It is worth taking time to carefully measure and cut cable to the exact size needed, as it will make for a neater installation, with less potential for confusion. It will also provide more space within each rack and/or cable manager for later expansion, which could save you a lot of money. This applies to both standard and patch cabling, and should be routine in any installation.
Get organised, and get labelling - All cables should be labelled at both ends on installation. This will prevent endless problems later trying to repair and troubleshoot, especially if you need to do it in a hurry, and don’t have time to label each one before patching. It’s also a good idea to colour-code cables in a logical way, as this makes identification much easier.
Testing, testing… - All cables and connections should be thoroughly tested on installation, and any problems fixed immediately. It is a lot easier to fix a problem at installation, when you know which cable is causing the trouble, than track down a connection problem later. Data centres should also have a good testing regime to make sure that cables stay functional and that problems do not develop later.
Prior preparation and planning - You will need to carry out running repairs at some point or another. A bit of time and thought at an early stage will prevent future problems. For example, make sure that you keep a stock of the most commonly-used cable lengths and types, and patch panels, which should be bagged and labelled, so that you don’t have to ‘borrow’ from unused equipment.
Document everything, and then keep the documentation updated - The layout of the data centre should be clearly and completely documented. This should include diagrams, and cover all racks, cabling, with cable types and counts, together with patching information. Ideally, the layout information should include guidance about installing future components, to maintain consistency. This documentation should be kept updated, either constantly, or on a regular basis.