Cat 6 vs Cat 6A vs fibre

For most new buildings the answer is a mix: Cat 6A for wireless access points and anything that needs 10 gigabit or high-power PoE, Cat 6 where budget is tight and needs are modest, and fibre for backbones between telecom rooms and buildings. The differences come down to bandwidth, distance, power delivery, cable size and cost.

The quick comparison

Cat 6

Cat 6 handles gigabit Ethernet to 100 metres and is the economical choice for desk outlets, phones, printers and cameras. It can also carry 2.5 and 5 gigabit multi-gigabit Ethernet in many installations. It supports 10 gigabit only over shorter distances and in favourable conditions, because of crosstalk from neighbouring cables (alien crosstalk). If you do not expect a device to need more than gigabit over the life of the cabling, Cat 6 is reasonable.

Cat 6A

Cat 6A is designed to carry 10 gigabit Ethernet across the full 100 metre channel. It has better shielding against alien crosstalk and usually uses heavier conductors. Two practical advantages follow:

• Access points. Current and next-generation WiFi access points use 2.5, 5 or 10 gigabit uplinks and draw substantial PoE power. Industry guidance commonly recommends Cat 6A for access point drops.
• PoE heat. Larger conductors and construction mean Cat 6A generally runs cooler in bundles carrying high-power PoE. See Power over Ethernet (PoE).

The downsides are cost, a larger outside diameter, a larger bend radius, and heavier bundles that fill trays and conduits faster. Pathways need to be sized for it, and terminating Cat 6A takes more care and time than Cat 6, which shows up in labour cost.

Shielded or unshielded?

Cat 6A comes in unshielded (U/UTP) and shielded (F/UTP and similar) versions. Shielded cable can help in electrically noisy environments and makes for slimmer cable, but the shield must be bonded correctly at the panel end, and every component must be shielded. Unshielded is simpler to install. Both work when installed properly; pick one system and follow the manufacturer's instructions.

Fibre

Fibre carries light rather than electrical signals, so it is immune to electrical interference, does not carry lightning or ground potential between buildings, and supports very high speeds over long distances.

• Multimode fibre (OM3, OM4, OM5) is used inside buildings and data centres over shorter distances, with lower-cost optics.
• Singlemode fibre (OS2) reaches much further and has effectively unlimited bandwidth for building purposes. It is the usual choice between buildings, and many designers now use it for new backbones because it will support future speeds.

Fibre cannot power devices. Where fibre runs to a remote device, local power or a hybrid cable is needed. Fibre connectors must also be kept clean; a dirty end face is one of the most common causes of fibre link problems.

A practical selection guide

• Access points: Cat 6A, often two drops per location
• Desk and wall outlets: Cat 6, or Cat 6A where budget allows
• Security cameras and access control: Cat 6 is usually enough; Cat 6A for heated or high-power outdoor units
• Backbone between telecom rooms: fibre, with spare strands
• Between buildings: singlemode fibre, rated for outdoor or underground use
• Data centre: fibre and Cat 6A according to equipment needs

Whatever you choose, every component in a link must be rated to the same category, and every link must be tested. See structured cabling standards.

A typical case: fitting out an office floor

Take a tenant fit-out on one floor of an office building. The plan calls for open-plan desks, meeting rooms, a reception area, ceiling-mounted access points and a few cameras at the entrances. One telecom room on the floor connects to the building's main room downstairs. A sensible cable plan might look like this:

1. Access points: Cat 6A to each planned access point location, with a second drop where the design allows for a future higher-speed access point or a second radio. Each drop is terminated on a jack or plug the access point can use directly, with slack left in the ceiling for small moves.
2. Desks: Cat 6 to each desk position, since most desk devices are laptops on WiFi and phones that need gigabit at most. If the tenant expects high-speed wired workstations, upgrade those positions to Cat 6A.
3. Meeting rooms: Cat 6A to the display location and table, since video systems and room control equipment often need higher speed or PoE.
4. Cameras: Cat 6, with outdoor-rated cable where it leaves the conditioned space.
5. Backbone: fibre from the floor telecom room to the main room, with spare strands, plus any copper the building's phone or security systems still require.

Pathways are then sized for the larger Cat 6A bundles, and the telecom room rack is laid out with room for patch panels for every drop.

Where the cost differences show up

Comparing cable price per metre gives a misleading picture. The real differences between Cat 6 and Cat 6A appear in:

• Labour: Cat 6A takes longer to pull and terminate, and errors are more likely if installers are rushed.
• Pathways: larger cable fills trays, J-hooks, conduit and sleeves faster, so more or larger pathways may be needed.
• Telecom rooms: stiffer cable needs more space for bend radius and cable management at the rack.
• Testing: Cat 6A testing includes more demanding limits, and fixing failed links takes time.
• Future work: replacing Cat 6 with Cat 6A in an occupied building later costs far more than the difference at construction.

Fibre adds costs of its own: optics in switches, splicing or field termination, and cleaning and inspection tools. Every link, copper or fibre, should be tested before handover; see cable testing and certification.

How ehZee can help

Our structured cabling design and build service starts by asking what the building needs to support now and later, then selects cable types, pathways and rooms to match, and tests every link before handover.

Common questions