Backbone wiring: the core of your network
Think of backbone or "vertical" cables as the central nervous system linking all your telecommunication closets, equipment rooms, and cable entrance facilities.
Because backbone cabling can be installed vertically in structural risers and elevator shafts, horizontally in cable tracks and conduits, or even between buildings, it is often further classified as inter-building or intrabuilding backbone cable.
The main job of any backbone system is to support many different applications.
It is also quite important to make sure your backbone can handle both current LAN applications and traffic loads as well as future demand for such services.

Recommended media for backbone cabling
Unshielded Twisted Pair (UTP)
Twisted Pair is the type of cabling most commonly used today because of its low cost, easy installation, flexibility for moves and changes, and ability to support the full LAN bandwidth.
Although originally designed for voice, twisted pair has seen numerous advances that make it suitable for telephones, workstations, terminals, and computer systems.
In fact, Category 5, the high-grade twisted pair, can support data speed to 100 Mbps, which is the speed of state-of-the-art computers and networking systems.
One important advantage of twisted-pair cable over non-twisted cable is resistance to crosstalk. The twists prevent interference from other pairs in the cable. For this reason, nontwisted-pair, four-wire cable, called "quad wire" is not recommended for multilane installations.
Twisted-pair cable is available in two main types: shielded and unshielded. Both are available in PVC or plenum versions. The plenum version, because it resists fire and produces less smoke when it burns, is requires for use in air plenums and dusts. The PVC version can be used in areas where smoke is less of a danger to building occupants.

Unshielded twisted-pair (UTP) cable: Choose 4-pair, 100-Ohm, solid-conductor UTP cable for short to medium distance backbone cable in voice and data networks.
Solid conductor cables are intended for stable runs and should not be subject to repeated flexing or twisting.
We recommend Category 5 or the newly ratified Enhanced Category 5 (CAT 5e) cable for new UTP installations to avoid expensive rewiring in the future.

Shielded twisted-pair (STP) cable: Use 2-pair, 150-Ohm shielded twisted twisted-pair cable for IBMR Token Ring network. Type 1A STP cable is constructed of four solid copper strands wrapped in a foil shield.
Type 2A STP cable includes an extra 4-pair UTP strand for phone circuits.
Fiber optic cable: Even though fiber is more expensive and requires more careful handling than other cables, it is the preferred medium for backbone cable because it offers maximum range, bandwidth, and flexibility.
Compact and lightweight, fiber provides high-speed transmission over a wide bandwidth.
Fiber also carries data over much farther distances than copper cable, and it is immune to EMI (electromagnetic interference). Fiber backbone cable is also far less likely to require replacement.

Coaxial cable: Although recognized by the TIA/EIA as a suitable, economical choice for backbone cable in small, Thin Ethernet (10-BASE2) applications, NEX1's technical experts do not recommend 50-Ohm coaxial cable for new installations.

Backbone topology
The TIA/EIA standard specifies a conventional hierarchical star topology for backbone cabling.
In a star topology, all the wiring on a network radiates from a central location call a main cross connect (usually the wiring closet).
Each telecommunications closet or entrance facility is cabled directly to the main cross-connect or can be cabled to it through intermediate cross-connect.

Horizontal Wiring
Most cables in a building are part of the horizontal wiring system. This includes all cables dedicated to premise switching equipment and telecommunication services, as well as LAN and data communication cables.
This kind of cables are installed during a building's construction phase, as part of the basic infrastructure, so once a building is completed, horizontal cables are far less accessible than backbone cables.
Future changes require much time, effort, and expense. That is why it is so important to consider your choice of horizontal cable and layout carefully, especially for new construction.