Specs from ANSI/TIA-568 & IEEE 802.3 · reviewed · the full Ethernet guide
The category printed on the box is a promise about speed, distance, and interference. Pick the one your run actually needs — under-spec and it will not certify; over-spec and you have paid for headroom you will never use. Answer four questions and this points to the right grade.
Recommended
Cat6a
10 Gigabit — Cat6a is the reliable 10G-to-100 m spec.
- A clean office run can use UTP Cat6a, but it is bulkier — foil (F/UTP) is the safe default.
- Bare copper only — copper-clad aluminum (CCA) will not certify and is a PoE and fire-code risk.
- Match the jacket fire rating to the space: CM (general), CMR (riser), or CMP (plenum), per the NEC.
The categories at a glance
| Category | Max speed & reach | Bandwidth | Typical shielding |
|---|---|---|---|
| Cat5e | 1 GbE to 100 m | 100 MHz | U/UTP |
| Cat6 | 10 GbE to ~55 m; 1 GbE to 100 m | 250 MHz | U/UTP |
| Cat6a | 10 GbE to 100 m | 500 MHz | F/UTP or U/FTP |
| Cat8 | 25/40 GbE to 30 m | 2000 MHz | F/UTP or S/FTP |
The reasoning behind each pick — the 10-Gigabit distance cutoff, why Cat7 is a marketing step, and the copper-vs-CCA problem — is in the full Ethernet guide. This selector is a sourcing starting point, not a substitute for a channel test on the installed link.
Sources
- Twisted-pair cabling categories (Cat5e–Cat8)ANSI/TIA-568
- Ethernet physical layers (1000/10G/25G/40GBASE-T, PoE)IEEE 802.3
Sourced to a real channel spec — in bare copper.
Kestner sources Cat5e through Cat6a patch and bulk cable to the category you actually need — bare copper, the right jacket rating, and cable verified to spec — from a US company that stands behind the paper.