Structured Cabling, Data, and Communications Infrastructure
Topology and distance limits
Structured cabling follows TIA-568 for cabling, TIA-569 for pathways and spaces, TIA-606 for labeling, and TIA-607 for grounding and bonding. Horizontal cabling is a star from the horizontal cross-connect to each outlet.
- Permanent link maximum is 90 m (295 ft); the channel is 100 m including patch cords, typically 10 m.
- Cat5e supports 1000BASE-T to 100 m; Cat6 supports 10GBASE-T to about 55 m; Cat6A supports 10GBASE-T to 100 m.
- T568A and T568B are both valid pinouts, but both ends of a link must match; a mismatch creates a crossover.
- Follow bend radius, pulling tension, and separation from power; label both ends per TIA-606.
Worked example
A 10GBASE-T link is 92 m of Cat6 plus 8 m of patch cords. The channel is 100 m, but Cat6 10GBASE-T is limited to about 55 m. The link may pass a basic wire-map test yet fail at 10G. The fix is Cat6A, fiber, or a shorter run.
Traps
Certifying only with a continuity tester; measuring length with a tone generator; assuming Cat6 always runs 10G at 100 m; mixing T568A and T568B; ignoring alien crosstalk.