Cabling Tips for Network Engineers
1. Label, label, label.
There’s nothing worse than arriving on site to carry out some work, only to find a cabinet that closely resembles a giant bird’s nest, and then to top it off, none of the cabling is labelled. Disconnecting cables can be a harrowing task even when the cabinet is neat and labelled, never mind when you have no clue what connects to what. Labelling cables may add an extra few minutes onto your work but it could save precious hours in the future should you have a critical failure.
2. Keep it neat, but not too neat.
As touched upon above, a cabinet with nice neat cabling is an engineer’s dream to work with. If cables are run across fronts of cabinets and over devices then remove and installing kit can be a difficult if not impossible task. Be careful though, keeping cabling too neat can also cause problems. Cross talk due to neat cabling is an unlikely but not impossible occurrence, cabling should be loosely bundled and randomly mixed to avoid this.
3. Keep it clean
Once you have finished your work, remember to remove any old cabling. Time is precious and the desire to get home ASAP is usually a strong one, but those few minutes spent removing dead cables are sometimes the most important. I've spent many an hour replacing user switches only to find that I'm left with too many cables when re-patching and then have to do a full end-to-end trace to find the culprits. Removing those old cables also improves airflow, especially under floor. It doesn't take long for that subfloor to become cramped.
4. Ooh, kinky.
Keep your cables, especially fibre and Cat6, kink free. Fibre cores can easily break or fracture by not looking after them. Make sure proper cable management is used in environments containing fibre, this will help to reduce kinks and bends in the cable. Ensure the correct conduits for Cat6 installations, due to a larger copper core, the cable requires a larger bend radius to prevent kinking.
5. You've gone too far
I know there are times when you may be caught short and need to get that new link in asap and all you have is a 10m cable to go 2m. However, there are a few things to consider when you do this. If the link is already running via interlinks, how far is that run? If it’s over 80m and you have only have 10m cables to use at either end then you’re close to the possibility that the link won’t work or will be unreliable. When using long cables to go a short distance then consider the strain that the length and weight will put on the cable. Over time, this could cause the cable to stretch and the signal to degrade.
6. I have the power
Make sure your copper cables don’t run parallel to electrical cables. They can act like inductors and create noise spikes over the link. Keep as much distance between data and power as possible. Also, consider other electrical interference in your data centre. Low power lighting, such as LED’s, will create a lot less electrical interference. Motors in air conditioning units should be kept as far away from data cabling as possible, and obviously on a different power source to reduce spikes in power as the motors kick in.
7. Think about those extra lbs
When running Cat6 through ceiling voids, etc then consider the extra weight that the thicker copper core introduces. If you have 100’s of these cables tightly strapped to a wire tray then cabling can easily become crushed causing signal degradation. Also think twice before really tightening that cable tie, or even using cable ties all together. Over tightening can easily pinch cables and due to the sharp edges on these ties, start to cut through cabling when the weight becomes too much. Consider using Velcro straps where possible. These will put less strain on the cables and can be easily reused, saving more £’s.
8. Don’t be cheap
As the old saying goes ‘You get what you pay for’ and that definitely applies to cabling. Cheap cables can have smaller than standard diameter copper cores, non pure copper cores, poorly regulated twist ratios and sub standard sheathing. These factors can all contribute to easily damaged cabling and signal degradation. Smaller diameter cores also cause interference when meeting standard core cabling as the impedance ratings don’t match.
9. Play it cool Trig
With the increase in popularity of Power Over Ethernet (POE), more power is pushed through the cabling with the infrastructure. With this increase in power comes an increase in heat created. Usually this heat is dissipated through cables jacket, however, if the cabling is installed in large bundles then this heat has nowhere to go. As the temperature rises, the electrical characteristics of the cabling changes impacting signal propagation. The likely hood of this occurring is reduced with CAT6 due to the larger copper core.
10. Plan ahead
Cabling is expensive and difficult to install in areas already in use. Although you may only have a hundred staff and a few cabinets at the moment, you could soon find yourself having to have more cable installed due to staff increases. Cabling is easier and more cost effective to install in one go, where possible try to avoid retrofitting additional cabling.