Structured Cabling System
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); transition points; and consolidation points
What Are the Benefits of Structured Cabling?
Once again, organization is the key word here. With an organized structured cabling system the benefits are:
- MAC’s are much quicker due to the fact that they are done in the MDA versus running long patch cords from equipment racks.
- Potential for downtime is reduced as potential for human error is drastically reduced due to this organization.
- Time savings; cable and port tracing becomes a much easier job with a structured cabling system.
- Aesthetics; Never underestimate the looks! A structured cabling system will look much cleaner than a point to point method. Since the changes are done in the MDA versus at the hardware, the hardware can be cabled up and not touched in most instances. This allows the cabling in front of the switch to remain aesthetically pleasing.
What Are the Risks Of Not Switching to a Structured Cabling System?
Downtime: With an unorganized messy cabling infrastructure, mistakes are commonly made. Incorrect ports are unplugged. Even worse is the messy cabling that gets in the way. Trying to remove a single cable from a large tangled mess can cause stress on the other cables. This stress can lead to network and channel errors in the hardware that are very difficult to trace.
Airflow: If a point to point method is used, the front and potentially the sides of the switch are congested with cabling bulk. This impedes the airflow that the switch needs to operate. This also translates to under floor cooling; cabling congestion in this space hinders the airflow of the CRAC unit and can cause cooling issues.
The Six Subsystems of a Structured Cabling System
This information is based on two standards: ANSI/TIA-568-C.0 (Generic Telecommunications Cabling for Customer Premises), which is used for generic infrastructures, and ANSI/TIA-568-C.1 (Commercial Building Telecommunications Cabling Standard), which is more commonly used with typical commercial building infrastructures.
1. Entrance Facilities (EF)
Entrance facilities contain the cables, network demarcation point(s), connecting hardware, protection devices and other equipment that connect to the access provider (AP) or private network cabling. It includes connections between outside plant and inside building cabling.
2. Equipment Room (ER)
The environmentally controlled centralized space for telecommunications equipment is usually more complex than a telecommunications room (TR) or telecommunications enclosure (TE). It usually houses the main cross-connect (MC) [Distributor C] and may also contain the intermediate cross-connects (ICs) [Distributor B], horizontal cross-connects (HCs) [Distributor A], or both.
3. Backbone Cabling
- Cabling Subsystem 2 – Backbone cabling between the horizontal cross-connect (HC) [Distributor A (DA)] and the intermediate cross-connect (IC) [Distributor B (DB)]
- Cabling Subsystem 3 – Backbone cabling between an intermediate cross-connect
(IC) [Distributor B (DB)] and the main cross-connect (MC) [Distributor C (DC)]
- 100-ohm twisted-pair cabling: Category 3, Category 5e, Category 6 or Category 6A
- Multimode optical fiber cabling: 850 nm laser-optimized 50/125 μm is recommended; 62.5/125 μm and 50/125 μm is allowed
- Single-mode optical fiber cabling
4. Telecommunications Room (TR) and Telecommunications Enclosure (TE)
A TR or TE houses the terminations of horizontal and backbone cables to connecting hardware including any jumpers or patch cords. It may also contain the IC or MC for different portions of the backbone cabling system. The TR or TE also provides a controlled environment to house telecommunications equipment, connecting hardware and splice closures serving a portion of the building.
The use of a telecommunications enclosure (TE) is for a specific implementation and not a general case. It is intended to serve a smaller floor area than a TR and may be used in addition to the minimum “one TR per floor” rule.
5. Horizontal Cabling – (Cabling Subsystem 1)
The horizontal cabling system extends from the work area’s telecommunications information outlet to the telecommunications room (TR) or telecommunications enclosure (TE). It includes horizontal cable, mechanical terminations, jumpers and patch cords located in the TR or TE and may incorporate multiuser telecommunications outlet assemblies (MUTOAs) and consolidation points (CPs). The maximum horizontal cable length shall be 90 m (295 ft.), independent of media type. If a MUTOA is deployed, the maximum horizontal balanced twisted-pair copper cable length shall be reduced.
- 4-pair 100-ohm unshielded or shielded twisted-pair cabling:
Category 5e, Category 6 or Category 6A
- Multimode optical fiber cabling, 2-fiber (or higher fiber count)
- Single-mode optical fiber cabling, 2-fiber (or higher fiber count)
6. Work Area
Work area (WA) components extend from the telecommunications outlet/connector end of the horizontal cabling system to the WA equipment.
A minimum of two telecommunications outlets (permanent links) should be provided for each work area. Multiuser telecommunications outlet assemblies (MUTOAs), if used, are part of the WA.