Structured cabling design and installation is governed by a set of standards that specify wiring data centers for data or voice communications using various kinds of cable, most commonly category 5e (CAT-5e), category 6 (CAT-6),. 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 normally 19 inch rack-mounted), 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. No adapter is needed in the U.S. as the 6P2C and 6P4C plugs most commonly used with RJ11 and RJ14 telephone connections are physically and electrically compatible with the larger 8P8C socket. RJ25 and RJ61 connections are physically but not electrically compatible, and cannot be used.
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.
a) Entrance facility (Carrier equipment and demarcation)
The entrance facility is the location where the Telecom Service Provider equipment and demarcation points or campus cabling interface