The structured cabling system begins at the point where the service provider (SP) terminates. For example, in a telephone system installation, the SP furnishes one or more service lines (per customer requirements). The SP connects the service lines at the point of demarcation.

Every structured cabling system is unique. This is due to variations in:

• The architectural structure of the building, which houses the cabling installation;
• The cable and connection products;
• The function of the cabling installation;
• The types of equipment the cabling installation will support — present and future;
• The configuration of an already installed system (upgrades and retrofits);
• Customer requirements; and
• Manufacturer warranties.

The U.S. cabling industry accepts the American National Standards Institute (ANSI), in conjunction with TIA/EIA, as the responsible organization for providing and maintaining standards and practices within the profession. It has published a series of standards to design, install, and maintain cabling installations. These help to ensure a proper cabling installation.

The benefits of these standards include:

• Consistency of design and installation;
• Conformance to physical and transmission line requirements;
• A basis for examining a proposed system expansion and other changes; and
• Uniform documentation.

Backbone cabling. From the entrance facility, the structured cabling network branches out to other buildings, as well as from floor to floor within a building on the backbone cabling system. We use the term backbone to describe the cables handling the major network traffic.

The main components of backbone cabling are:

• Cable pathways: shafts, conduits, raceways, and floor penetrations (such as sleeves or slots) that provide routing space for the cables.
• The actual cables: optical fiber, twisted-pair copper, coaxial copper, or some combination of these. (Note: You should avoid areas where potential sources of EMI or electromagnetic interference may exist when planning the routing and support structure for copper cabling.)
• Connecting hardware: connecting blocks, patch panels, interconnections, cross-connections, or some combination of these components, and
• Miscellaneous support facilities: cable support hardware, fire-stopping, and grounding hardware. Note: The terms horizontal and backbone (previously called riser) evolved from the orientations typical for functional cables of these types. However, the physical orientation of the cabling has no bearing on classifying the cable as horizontal or backbone.

Cabling connectors: A connector is a mechanical device you use to interface a cable to a piece of equipment or one cable to another. The role of the connector is to provide a coupling mechanism that keeps loss to a minimum.

In the case of fiber, it allows light impulses to transfer from one connector to another. For copper, it allows electrical signals to transfer from one connector to another.