Structured Cabling… is defined as building or campus telecommunications cabling infrastructure that consists of a number of standardized smaller elements (structured).
Structured cabling installations typically include: entrance facilities, vertical and horizontal backbone pathways, vertical and horizontal backbone cables, horizontal pathways, horizontal cables, work area outlets, equipment rooms, telecommunications closets, cross-connect facilities, & multi-user telecommunications outlet assemblies (MUTOA).
Structured cabling begins at the demarcation point of a building. The demarcation point, or demarc, is the point in a building where a service provider delivers phone lines and data circuits. From there it is up to the customer to design a structured cabling system that then takes those services, connects them to their network hardware, and ultimately deliver phone lines and data connection points for computers at employees’ desks. In larger multi-story buildings, telecommunications closets are normally stacked on top of each other on each floor of a building. Carrier services can be extended into each of these telecommunications closets, and then extended into each tenant’s suite on their respective floor.
A facility typically will have a Main Distribution Frame, or MDF. This MDF houses the network equipment which takes local devices and equipment (inside plant), and connects them to cables and subscriber carrier equipment for connections beyond the local facility (outside plant). The services that are delivered at the demarcation point are extended to this MDF for connections inside the building. The MDF will typically have data racks that include network routers, switches, modems as well patch panels for terminations of cabling that is ran throughout the building. Using a ladder tray is best practice for routing cabling to data racks inside the MDF from the backbone cable pathways typically in the ceiling.
Larger buildings may require an Intermediate Distribution Frame, or an IDF. An IDF is simply a cable rack that interconnects and manages the telecommunications wiring between an MDF and workstation devices. An IDF connects users to the MDF; In contrast a MDF connects users to carrier services. Depending on the function of a data cable, the limit in which a data cable can be pulled is 100 meters. This means that if there is an endpoint such as a workstation device that is farther than 100 meters from the MDF, an IDF will need to be installed.
Horizontal and vertical backbone pathways are used to extend cabling from the demarcation point, to the MDF. Backbone pathways are also used to extend cabling from a MDF to an IDF. These backbone pathways include a type of cable support which houses the cabling infrastructure in an organized manner. The cabling support is installed along walls, or mounted directly to the structure of a building. Support points are typically installed every 4-6’ on the backbone pathways to suspend cable without having too much droop, or sag between support points. Keeping support points at this distance limits the droop between supports, as well as limits unnecessary force from gravity as the sagging cables pull on the nearest support point. There are many different choices in support systems, just as there are many different designs of buildings and their structure. The amount of cabling needed for endpoint devices, as well as the design of a building can determine which type of cabling support will work best for that particular environment. A properly designed cabling system will be adequately labeled at each endpoint for troubleshooting purposes as well as ease in Moves, Adds, or Changes. Depending on what type of communication cabling is used, (ie: Fiber Optic/Cat5e/Cat6), bend radiuses as well as distance from electrical components must be taken into consideration. The local wiring/electrical codes of the area must also be considered when designing structured cabling systems.
Structured cabling is simply a term used in a properly designed way of getting cabling from carrier services to endpoint users. While there are several components in a businesses’ network topology, a properly designed structured cabling system is imperative for reliable data transmission.