Data Center Cabling Solutions
What is Structured Cabling?

What is Structured Cabling?

  • Mar 23, 2009
  • pbelyea


We talk about structured cabling all the time but when a newbie asks about it how do you explain it? While presenting to a small group of new employees one of them presented me with this Wikipedia definition. I have now added it to my general training materials. Feel free to use it but be sure to give credit to the source.

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

These standards determine how to wire a data center, office or apartment building for data or voice communications, using Category 5(CAT 5E) or Category 6 cable(CAT 6E) 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 'telecom???s 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 to the network.   It is normal to see different color 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.

Cabling standards demand that all eight connectors in Cat5/5e/6 cable are connected, resisting the temptation 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 (POE) which require the so-far unused brown cables.