Cabling
Backbone Cabling
Also known as: Vertical Cabling, Riser Cabling
Connects network equipment rooms, floors, and buildings to each other — the high-capacity trunk infrastructure that horizontal cabling plugs into.
Structured cabling follows a hierarchy. At the top is the main distribution frame (MDF) — typically in the data center or main IDF. Backbone cabling runs from the MDF to intermediate distribution frames (IDFs) on each floor or in each building. From the IDFs, horizontal cabling fans out to individual workstations, APs, and devices.
Backbone runs carry aggregated traffic — multiple floors' or buildings' worth of connections — so the bandwidth requirements are higher and the appropriate media is different:
Within a building (vertical) — multimode or single-mode fiber is standard for modern installations. Fiber handles longer runs, higher bandwidth, and is immune to EMI. 10G or 25G per fiber pair is common; 40G/100G in higher-density environments.
Between buildings (campus) — single-mode fiber, which maintains signal quality over hundreds of meters to kilometers. Outdoor-rated, often direct-buried or in conduit.
Short inter-rack runs — DAC (Direct Attach Copper) cables or short-reach fiber are common for sub-10-meter connections between adjacent racks.
Backbone cabling is expensive to run and disruptive to change after the fact — running it once correctly, with adequate spare fibers or conduit for future growth, is a much better investment than a minimal installation you'll need to supplement in two years.