Cat6 vs fibre: what an office actually needs

Every office build eventually hits the same question: do we run Cat6 everywhere, or pay for fibre? The answer is almost always both, just in different places.

What Cat6 actually does

Cat6 carries 1 gigabit comfortably to 100 metres and 10 gigabit to about 55 metres, which covers nearly every desktop run in a normal office. It also carries power (PoE), which is how modern phones, cameras, and access points avoid wall warts. A good Cat6 run, properly terminated, tested, and labelled, will still be boring and reliable in 2036.

The spec that matters for copper is not the cable box, it is the termination. A perfect box of cable ends badly at a bad jack, and nobody finds out until a workstation drops packets under load.

Where fibre earns its keep

Fibre is for the runs copper cannot do well:

• Between floors or buildings, where distance and grounding get ugly
• From the internet entry point to the network room, so a provider handoff does not cap the whole office
• Between switches, so the backbone never becomes the bottleneck
• Anywhere the cable path runs near heavy electrical gear

Single-mode fibre is the quiet standard here. The cable is cheap; the optics are the cost, and prices have dropped far enough that a 10 gig backbone is no longer exotic.

What most offices actually need

Copper to every desk, fibre for the backbone and the long hauls, and a patch panel with labels you can read in five years. The expensive mistakes are rarely the cable choice. They are the missing labels, the untested runs, and the future you with no documentation when a tenant improvement knocks out half a floor.

Spend on the certification test, not the marketing on the box.