Structured cabling

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Structured Cabling is defined as building or campus telecommunications cabling infrastructure that consists of a number of standardized smaller elements (hence structured) called subsystems.

Structured cabling falls into the following six sub-systems:

• Entrance Facilities is where the building interfaces with the outside world.
• Equipment Rooms host equipment which serves the users inside the building.
• Telecommunications Rooms are where various telecommunications and data equipment resides, connecting the backbone and horizontal cabling sub-systems.
• Backbone Cabling as the name suggests carries the signals between the entrance facilities, equipment rooms and telecommunications rooms.
• Horizontal Cabling is the wiring from telecommunications rooms to the individual outlets on the floor.
• Work-Area Components connect end-user equipment to the outlets of the horizontal cabling system.

Structured cabling design and installation is governed by a set of standards that determine how to wire a data center, office or apartment building for data or voice communications, using Category 5 or Category 6 cable and modular sockets. These standards define how to lay the cabling in a star formation, such that all outlets terminate at a central patch panel (which is normally 19 inch rack-mounted), from where it can be determined exactly how these connections will be used. Each outlet can be 'patched' into a data network switch (normally also rack mounted alongside), or patched into a 'telecoms patch panel' which forms a bridge into a private branch exchange (PBX) telephone system, thus making the connection a voice port.

Lines patched as data ports into a network switch require simple straight-through patch cables at the other end to connect a computer. Voice patches to PBXs in most countries require an adapter at the remote end to translate the configuration on 8P8C modular connectors into the local standard telephone wall socket. In the U.S., no adapter is needed, as the 6P6C plug used with RJ11 telephone connections is physically compatible with the larger 8P8C socket and the wiring of the 8P8C is compatible with RJ11. In the UK, an adapter must be present at the remote end as the 6-pin BT socket is physically incompatible with 8P8C.

It is normal to see different colour patch cables used in the patch panel to help identify which type of connection is being carried, though the structured cabling standards do not require this, except in the demarcation wall field

The standards demand that all eight connectors in the Cat6 cable are connected, resisting the tempation to 'double-up' or use one cable for both voice and data. This is generally a good thing as it means that they fully support features such as Power over Ethernet which require the so-far unused brown cables.

[edit] See also

• ISO/IEC 11801 – the International Standards Organization standard for generic cabling for premises
• TIA/EIA-568-B - The Electronic Industries Alliance standard for telecommunications cabling in commercial premises
• registered jack - A set of standards for telephone cabling termination (including RJ11, RJ14, etc.)