Structured copper cabling — Cat6 and Cat6A

Horizontal runs from patch panel to work-area outlet, vertical runs between floors, keystone and patch-panel termination with a calibrated punch-down tool, faceplate assembly, and cable management in the rack with horizontal and vertical managers. Every horizontal link is kept under 90 metres so that the standard 100-metre channel is respected.

If your network runs at gigabit today and will not need 10 gigabit over copper within five years, Cat6 is enough. But if you are deploying Wi-Fi 6E and 7 access points, high-bitrate cameras on PoE++, or switch-to-switch links over copper, Cat6A is the right choice: it guarantees 10 gigabit over the full 100 metres, and its screened construction handles PoE heat better.

The difference in material cost is usually smaller than people expect; the real cost is pulling the cabling a second time.

• Bending the cable tighter than the minimum radius — the link may work and still fail the test.
• Untwisting more than 13 mm of pair at the termination.
• Running alongside power cables with no separation.
• Overfilling the tray, which crushes the cables underneath.
• No labels and no drawings — a cost you pay years later.

TIA-568 defines a channel of up to 100 metres, but that 100 metres is not all cable in the wall: 90 metres is the fixed run from patch panel to outlet, and the remaining 10 are the patch cords at each end. Take the fixed run to 100 metres and the link can pass a Permanent Link test and fail as a Channel — which is the configuration the user actually works in.

Two things upset that arithmetic. The real route is always longer than the straight line on the drawing: up to the ceiling, around a beam, down a riser. And the service loop we leave above the rack and behind the outlet, so that re-terminating years later — when a keystone breaks — does not mean pulling new cable. Both are counted into the length before anything is pulled, and borderline routes are marked on the installation drawing rather than discovered afterwards.

With PoE Type 3 and Type 4 — up to 60 and 90 watts per port — a cable no longer only carries data; it also generates heat. In a tight bundle the middle cables run hottest, and insertion loss rises with temperature. In practice: a link tested in an empty, cool building can lose its margin in summer under full PoE load.

So we limit how many cables go into one bundle rather than tying one large one, keep high-power PoE routes separate, use a heavier conductor (23 or 24 AWG) and avoid thin 28 AWG patch cords on high-power ports, and prefer a shielded construction in dense installations, where the foil also helps spread heat. TSB-184-A is the guidance behind these decisions.

Good cable with poor termination becomes a poor link. The work here is simple and unforgiving: strip only as much jacket as needed, keep pair untwist to a minimum — for Cat6 and Cat6A typically under 13 mm, and to the keystone manufacturer's figure — punch down fully with a calibrated tool, and keep one colour code across the whole project.

Shielded cable adds one condition: shield continuity has to survive the whole path and reach earth at the rack. A shield left floating at one end performs worse than no shield at all — instead of a screen, it becomes an antenna.

None of these mistakes hides in the test report, and each has its own signature: too much untwist shows up in NEXT; a tight bend or over-tensioned pull shows up in return loss; an incomplete punch-down appears as a wire map or resistance-unbalance failure. That is why we treat testing as the daily quality measure for each floor, not as a formality at handover.

Most serious cable damage happens while pulling, not afterwards. Two numbers decide it: the minimum bend radius, around four times the cable diameter for a four-pair cable during installation and more for shielded constructions, and the maximum pull tension, about 110 newtons — roughly eleven kilograms — for a four-pair cable. Exceed either and the pair geometry is disturbed; the link may still link, and still fail the test.

In the pathway itself a few rules are kept strictly: trays are not filled past roughly forty per cent of capacity, so the bottom cables are not under load; ties are firm but never deform the jacket; and separation from power cabling follows the EN 50174-2 tables — not a single fixed number, but a distance that depends on the cable's screen, the pathway material and how far the two run in parallel. Where a crossing with a power route is unavoidable, we cross at a right angle rather than run alongside.

Every port is labelled identically at both ends, under one naming scheme for the whole building based on TIA-606: floor, rack, panel and port. The label on the cable jacket, on the faceplate and on the patch panel must be the same one, or the drawing is of no use.

Handover includes three things: an as-built drawing showing the route as installed rather than as designed, a port book tying every port number to its room and its user, and the complete test report as a file. Together they are what lets your support team find one port in minutes three years from now, instead of tracing a cable from the rack to the room.

• Included: cable, keystones and patch panels, faceplates and boxes, pulling and termination, rack organisation, labelling, a test of every port, the formal report and the as-built drawing.
• Project-dependent: the pathway itself (tray, ladder, trunking, conduit or floor boxes), the rack and its accessories, earthing, and any building work the route needs.
• Not included: active equipment. We will supply and commission it if you want us to, but it stays out of the passive estimate so that comparing quotations stays honest.

The estimate is itemised, because an itemised estimate can be compared: two quotations each given as one total never can.