Structured cabling for offices: Cat6 vs Cat6a and how to plan it

Cabling is the least glamorous part of an office network and the hardest to change later. It sits in ceilings, under floors and inside walls, and carries computers, desk phones, Wi-Fi access points, printers and cameras. Get it right once and you won't think about it for years. Get it wrong and you'll be chasing faults.

This guide explains what structured cabling is, how Cat6 and Cat6a compare, when fibre makes sense, and how to plan a cabling job.

What is structured cabling?

Structured cabling is a planned, standardised way of cabling a building. Every data point is cabled back to a central patch panel in a comms room or cabinet. Short patch leads then connect each point to your network equipment.

The benefits:

• Tidy and easy to manage. Every point is labelled.

• Flexible. Moving a desk phone or adding a printer is a patch-lead change.

• Reliable. Planned, properly terminated runs mean fewer faults.

Copper cabling: Cat5e, Cat6 and Cat6a

Most cabling to desks and devices is copper twisted-pair cable, graded into categories.

Cat5 and Cat5e

Cat5e is fine for everyday office use. For new installations, most businesses now choose Cat6 or Cat6a.

Cat6

Cat6 is specified up to 250 MHz. It handles gigabit networking comfortably and can carry 10 Gbps over shorter runs, up to 55 metres.

Cat6a

Cat6a ("augmented" Cat6) is specified up to 500 MHz and supports 10 Gbps Ethernet over the full 100-metre channel. It is thicker and stiffer than Cat6, so it takes more space and care to install.

Cat6 vs Cat6a at a glance

Specified frequency: Cat6 up to 250 MHz; Cat6a up to 500 MHz.

10 Gbps Ethernet: Cat6 up to 55 m; Cat6a up to 100 m.

Cable size: Cat6 thinner and easier to route; Cat6a thicker and needs more space.

Good for: Cat6 everyday use and shorter runs; Cat6a new installs, Wi-Fi access points, longer runs and future-proofing.

Which should you choose?

Choose Cat6a if:

• You're cabling a new office or doing a full refit

• You're installing modern Wi-Fi access points

• You have long runs back to the comms room

• You want the cabling to last through several generations of equipment

Cat6 can be fine if:

• Runs are short and connect desks, phones and printers

• You're extending an existing Cat6 installation

• Space in ceilings and trunking is tight

Because cabling outlasts equipment, many businesses decide Cat6a is worth the extra on a new install. We'll give you an honest recommendation for your building.

Where fibre fits in

Copper is limited to 100 metres per channel. For longer distances, links between floors or buildings, and between comms rooms, fibre optic cabling is usual. A common design is a fibre backbone between comms rooms, with copper out to desks. Fibre also carries incoming leased-line connections.

How to plan a cabling job

• Count data points for desks, phones, printers, Wi-Fi access points, cameras, meeting rooms and door entry. Add spares.

• Decide where the secure, ventilated comms cabinet goes, with power and space for broadband, switches and patch panels.

• Plan Wi-Fi access point positions at the same time, then cable them in.

• Choose Cat6 or Cat6a, plus fibre where needed. Label everything and plan timing around your business.

Signs your cabling needs attention

• Network faults or connections that drop when cables are touched

• A comms cabinet nobody can make sense of

 Unlabelled cables, extension leads and switches under desks

• Not enough data points, or poor call quality on desk phones

Cabling for phones and Wi-Fi

Desk phones for a cloud phone system and Wi-Fi access points both plug into your cabling and often take power from it. If you're changing your phone system before the 2027 switch-off, check the cabling too.

Frequently asked questions

What's the difference between Cat6 and Cat6a?

Cat6a is specified to a higher frequency (500 MHz vs 250 MHz) and supports 10 Gbps over the full 100 metres. Standard Cat6 supports 10 Gbps only up to 55 metres.

Is Cat6a worth it for a small office?

For a new install, often yes, because cabling outlasts the equipment. For short runs, or for extending existing Cat6, Cat6 can be fine.

Can I still use Cat5e?

For everyday use it often works, but for new cabling most businesses choose Cat6 or Cat6a.

When do I need fibre?

For runs longer than copper allows, between floors or buildings, and for links between comms rooms.

How many data points does each desk need?

Usually at least two, plus points for phones, printers, access points and meeting rooms, and some spares.

Get a cabling quote

Crystal Voice Data installs data cabling in Cardiff and across South Wales: Cat 5, Cat 6, Cat 6a and fibre, for offices and comms rooms. We're a local team, and we also do phones and Wi-Fi, so it all works together. Call 0333 5678 444 (Monday to Friday, 9am to 5pm) or book a site survey.