Copper Data Products

Category, Screening and Termination in Copper Data Cabling

Copper data cabling forms the backbone of office and in-building networks. A copper channel consists of the permanent link running from the floor distributor to the work area outlet (solid-conductor cable, patch panel and keystone jack) plus the flexible patch cords at both ends. Standards limit the total channel length to 100 metres: 90 metres of permanent link and 10 metres of patch cords. This limit cannot be stretched; beyond it, attenuation prevents the link from passing certification.

Category selection determines the frequency the link can carry. Cat6 is the 1 Gigabit Ethernet standard at 250 MHz and supports 10 Gigabit up to about 55 metres. Cat6A offers 500 MHz, carries 10 Gigabit across the full 100 metres and uses a thicker construction that controls interference between adjacent cables (alien crosstalk). In Cat7 S/FTP each pair is individually foil screened and the whole cable is braided, designed for industrial sites and high-interference environments. Category is not limited to the cable: jacks, outlets and patch panels must share the same class.

Screening is decided by the environment. U/UTP (unscreened) construction is sufficient in normal office environments; it is easy to install, lower in cost and needs no bonding. F/UTP places a single foil over the pairs to suppress external interference. In S/FTP each pair is foiled and the whole cable braided. In screened systems, end-to-end screen continuity and correct bonding are essential; a half-finished screen can perform worse than an unscreened cable.

Permanent links use solid conductors while patch cords use stranded conductors. Solid conductors offer lower resistance and better performance over distance, whereas stranded conductors withstand repeated flexing. For this reason patch cord cable is never pulled into ducts, and patch cords are never made from solid cable. Horizontal cables typically use 23 AWG conductors and patch cords 24 AWG.

As PoE (Power over Ethernet) spreads, thermal management has become part of cable selection. Current feeding IP cameras, access points and IP phones heats the cable bundle; as temperature rises, conductor resistance and attenuation increase. Projects with heavy PoE favour thicker conductors (23 AWG), smaller bundles and well-ventilated routes. Cat6A cables operate with a safer margin under these conditions, both thermally and in performance.

Termination quality matters as much as cable quality. At a keystone jack or patch panel, the longer the pairs are untwisted the worse the NEXT value becomes; the standard limits this to 13 mm. Toolless jacks allow fast termination without tools, while 110 IDC panels are terminated with a punch down tool. Channel testing after installation is recommended both for warranty and for fault diagnosis.

Frequently asked questions about copper cabling

Should I buy Cat6 or Cat6A?

If the current requirement is 1 Gigabit, Cat6 is sufficient. However, cabling is infrastructure that stays in service for 15-20 years and replacing it later means construction work. In new installations, especially where a move to 10 Gigabit or heavy PoE is likely, Cat6A is preferred.

Why are patch cords not made from solid cable?

Patch cords are plugged, unplugged and flexed constantly, and solid conductors break under repeated bending. Patch cords therefore use stranded conductors; conversely, stranded conductors have higher attenuation and are not used in permanent links.

Do I need screened (FTP/STP) cable?

U/UTP is adequate in a normal office environment. Routes parallel to high-voltage lines, industrial machinery areas, hospital imaging rooms or very densely packed data center racks call for screened cable. If a screened system is chosen, end-to-end screen continuity and bonding are mandatory.

How does PoE affect cable selection?

Current carried over PoE heats the cable bundle, and rising temperature increases attenuation. Projects with heavy PoE favour thicker conductors such as 23 AWG, smaller bundles and ventilated routes. Cat6A provides a wider safety margin under these conditions.

Is testing after installation necessary?

Channel testing is recommended for system warranty and clean commissioning. Testing measures attenuation, NEXT, return loss and length to document that the link genuinely meets the target category. Termination faults usually surface only during testing.

Which components must share the same class in data cabling?

Channel certification is granted according to the weakest component. Cable, keystone jack, patch panel and patch cord must therefore all be of the target category (e.g. Cat6A). Fitting a Cat6 jack to Cat6A cable makes the link a Cat6 channel.