Structured Cabling Basics: Cat6, Cat6a, Fiber, and What to Specify

A practical guide to commercial structured cabling — categories, bandwidth, distance limits, and the right specification for office, data centre, and outdoor applications.

Cable categories explained

Category 5e (Cat5e): supports 1 Gigabit Ethernet up to 100m. Considered legacy for new installs but still common in retrofits. Category 6 (Cat6): supports 1 Gigabit at 100m and 10 Gigabit up to ~55m. Standard choice for most office wiring. Category 6a (Cat6a): supports 10 Gigabit Ethernet at full 100m. Specified for high-density areas (data centres, AV systems, PoE++ cameras). Category 7 / 7a / 8: short-distance data centre cables, rarely used in office cabling.

When to choose fiber

Fiber optic is required for: distances over 100m (Ethernet limit), inter-building runs, electrically noisy environments (factory floors near motors), and high-bandwidth backbones (10G+ uplinks between switches). OM3 multimode supports 10G to 300m, OM4 to 400m. Single-mode (OS2) supports 10G+ to tens of kilometres.

TIA-568 cable structure

A structured cabling system follows the TIA-568 hierarchy: work area (the cable from PC to wall outlet) → horizontal cable (wall outlet to floor distributor) → backbone (floor distributor to building distributor or campus distributor). The hierarchy enables systematic troubleshooting and moves/adds/changes.

What TSB Smart Tech installs

TSB Smart Tech specifies Cat6 U/UTP as the default for general office wiring, Cat6a F/UTP for data centre and AV distribution, and OM4 fiber for backbones and outdoor runs above 100m. All structured cabling is tested to TIA-568-C performance with documented Fluke test reports provided at handover.

Frequently asked questions

Should I install Cat6 or Cat6a in my new office?

Cat6 for general workstation drops (most cost-effective). Cat6a for backbone uplinks, dense AV zones, and PoE++ camera runs (60W+). The price difference for a small office is rarely significant; the difference for a large building is substantial.

How long does structured cabling last?

Properly installed structured cabling is rated for 20-25 years. The cable will outlast multiple generations of equipment connected to it — your switches and computers will be replaced 3-5 times before the cable needs to be re-pulled.

Is shielded (STP) better than unshielded (UTP)?

Shielded cable (F/UTP, S/FTP) is required in high-noise environments (industrial floors, near radio equipment) and at Cat6a for guaranteed performance. For standard offices, U/UTP is sufficient and cheaper. The shield must be properly grounded to be effective.

What documentation should I receive at handover?

A cable schedule (every outlet labelled), as-built drawings, test results for every link (insertion loss, return loss, NEXT, ACR-F), warranty certificates, and recommended retest interval. TSB Smart Tech provides this documentation as standard.