The secondary cabling is an in-building cabling to connect the floor distributors with the building distributors.
This cabling is also referred to as building cabling. Secondary cabling is vertical cabling used to connect the individual floors to the building distributor in a star configuration.standards, fiber optic and symmetrical copper cables are suggested as alternatives for universal cabling in the secondary area. Both multimode fibers and single-mode fibers can be used, with 62.5/125 µm gradient fibers being used in practice. Secondary cabling is limited to 500 m and must not exceed a maximum attenuation of 11 dB. For high-speed applications over TP cables, the maximum distance is limited to 100 m.