Internet Services

Network Cabling

Once all planning requirements have been met, the correct and sufficient infra-structure has been provided, the physical cabling of the network can begin. The manner, aestetics and cosmetics all contribute to the over-all “look” and quality of the end result of the installation. To to prevent cable twisting, and ensure neatness and quality of any cable installation, cables should be pulled in from the termination point back to the patch panel in bundles of 24 cables. Special care must be taken whilst installing the cable bundle into the trunking provided.

All to often infra-structure planning for I.T. networks is neglected. In the past it was general practice to install U.T.P. cable together with the voice (telephone) cable in the same trunking. Even electrical engineers and architects do not provide for sufficient, dedicated I.T. routes. Nowadays however, with the increasing demand for speed and bandwidth, keeping negative influences such as EMI, RFI and Crosstalk in mind, it is safe practice to ensure that power, voice and data each be provided with dedicated routes as indicated in the picture below.

Cable bundles of 24 cables inside dedicated routes should be loomed and cable tied within their containment to eliminate risk of damage when additional cabling needs to be installed.

Where information outlet boxes are not mounted directly on the dedicated trunking (normally P9000) conduit should be used to contain cables from the main trunking to the Informati

on outlet. The dayglow pink was used in the planning phase to mark the mounting positions of the information outlet boxes. Due to the brightness of the colour it is now also easy to locate the position of the Information Outlet after the ceiling boards have been closed. This adds quality to any installation.

Slack of loomed cables within dedicated trunking should be coiled under the plinth before being routed via the cable tray mounted on the left hand side of the cabinet. The plinth should be 600mm long to ensure unobstructed opening of the rear door.

From the plinth, loomed cable bundles are neatly secured to the cable tray. This tray should not be less than 300mm wide in a 43U cabinet, 200mm wide in a 25U cabinet and 150mm
wide in a 9U cabinet. Minimum bend radius should be carefully considered before terminating on the patch panel. Note that the patch panels have rear mount cable organizers securing the cables before termination.

Passive and active components are arranged separately. The top half of the cabinet is reserved for patch panels and brush panels whilst the bottom half is reserved for hubs/switches and brush panels. The brush panels have no effect on the link performance and are purely cosmetic. Their value lies in the neatness of patch cord routing via the Patch Guide Tray mounted on the right hand side of the cabinet.

The picture below indicates the top half of a populated 43U cabinet (passive half). Patch Panels are configured in the following manner. The top 1U should be a blanking plate to allow for space so that the cooling fans are effective. Below that is the Fibre Optic Link panel/s. Below that is the first UTP link Patch Panel/s. Below that is the first brush panel. Below that the 24 port horizontal cabling patch panels each separated by a brush panel to allow for routing of patch cords.

Patch Panels are labeled “A” “B” “C” etc. Link patch panels are labeled “Links” . Patch cords are a standard length of 2 meters due to the fact that passive and active components are separated. Each patch cord is individually labeled at both ends and dedicated to a patch panel port. This is done due to the fact that buildings are mostly saturated, meaning that there are more LAN points cabled than was initially requested, and that the installed equipment might not be sufficient to bring every point live. The Picture above shows the passive (top) half of a cabinet that has been patched. These patch cords are routed through the brush panel via the Patch Guide Tray to the active (bottom) half of the cabinet. The picture below shows the same Passive (top) half of the cabinet from the rear. Note the neatness of the patch cord routing via the Patch Guide Tray.

Below are pictures of what happens once quality is absent from cable installations. Any body can install UTP from a patch panel to an outlet box. Any product is used, resulting in poor performance with little or no reliability and no course of reaction.

Anyone can pull cable in, but is there quality? Cabling, tends to look like the picture above, showing a cabinet where the doors have been removed and patch cords look more like a tangled mess than anything related to I.T. cabling the way that it should be. Without proper demand forecasting cable routes are often not of sufficient capacity to hold the required amount of cables needed.

Without proper records end users often resort to their own form of cabling as shown above. This could be controlled once proper documentation and test results of all newly installed points are available.

In conclusion, a quality product installed by an endorsed installer according to a proper plan meeting all the requirements of the client together with insight of demand forecasting will result in lower maintenance costs and far less down time. Doing this therefor also facilitates accurate record keeping, and planning of expansion becomes a logical next step.