Structured cabling is the design and installation of a cabling system that will support multiple hardware uses and be suitable for today's needs and those of the future. With a correctly installed system, current and future requirements can be met, and hardware that is added in the future will be supported. In the
OSI model structured cabling is a form of
physical/transmission media.
Design How structured cabling will look is size dependent; a small office will not have the same hierarchical depth as a
building,
platform,
factory or campus.
Example Small Office In a small office, you might have a single Building distribution room that handles both external connections and horizontal cabling to all telecommunications outlets. With a small structure, there is no need for backbone cables. • External network interface is the location the service provider normally an ISP. • BD Building distribution is the building entrance facility and represents the central point where external services enter and all internal networking equipment (switches, patch panels) resides. • TO represents one or more telecommunications outlet. Horizontal cabling is used to connect the outlets.
Example Large Office A large, multi-floor office requires a more complex hierarchy, involving a Building distribution room with central equipment and multiple floor distribution (FD) with local equipment on different floors. Backbone cabling connects the BD to the TDs. . • External network interface is the location the service provider normally an ISP. • BD Building distribution is the building entrance facility and represents the central point where external services enter and central internal networking equipment (switches, patch panels) resides. • FD floor distributor, represents a point where floor networking equipment (switches, patch panels) resides. • TO represents one or more telecommunications outlet. Horizontal cabling is used to connect the outlets.
Hardware Structured cabling design and installation is governed by a set of standards that specify wiring
data centers,
offices, and
apartment buildings for data or voice communications using various kinds of cable, most commonly
Category 5e (Cat 5e),
Category 6 (Cat 6), and
fiber-optic cabling and
modular connectors. These standards define how to lay the
cabling in various
topologies in order to meet the needs of the customer, typically using a central
patch panel (which is often mounted in a
19-inch rack), from where each modular connection can be used as needed. Each outlet is then patched into a
network switch (normally also rack-mounted) for network use or into an IP or PBX (
private branch exchange) telephone system patch panel. Lines patched as data ports into a network switch require simple
straight-through patch cables at each 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 North America no adapter is needed for certain uses: With ports wired in the preferred standard
T568A pattern, for the 6P2C plugs most commonly used for single-line phone equipment (e.g. with
RJ11), and 6P4C plugs used for two-line phones without power (e.g. with
RJ14) and single-line phones with power (again RJ11), telephone connections are physically and electrically compatible with the larger
8P8C socket, but with ports wired as
T568B, which is common but often in violation of the standard, only the first pair, i.e.
line 1, works.
RJ25 and
RJ61 connections are physically but not electrically compatible, and cannot be used. In the United Kingdom, an adapter must be present at the remote end as the
6-pin BT socket is physically incompatible with 8P8C. It is common to color-code patch panel cables to identify the type of connection, though structured cabling standards do not require it except in the demarcation wall field. Cabling standards require that all eight conductors in Cat 5e/6/6A cable be connected. IP phone systems can run the telephone and the computer on the same wires, eliminating the need for separate phone wiring. Regardless of copper cable type (Cat 5e/6/6A), the maximum distance is for the permanent link installation, plus an allowance for a combined of patch cords at the ends. Cat 5e and Cat 6 can both effectively run
power over Ethernet (PoE) applications up to . However, due to greater power dissipation in Cat 5e cable, performance and power efficiency are higher when Cat 6A cabling is used to power and connect to PoE devices. ==Subsystems==