The Components of Structured Cabling
Structured cabling refers to the telecommunications infrastructure for commercial premises. This infrastructure is made up of different subsystems, each with its own established array of components governed by network cabling codes and standards. For commercial buildings in the United States, these standards are referred to as ANSI/TIA-568 which was issued by the American Standards Institute and the Telecommunications Industry Association, hence ANSI/TIA.
Structured cabling standards
The standards issued for structured cabling cover the complete environment dedicated to data transmission for the premises. This includes phones and voice, internet access, fax, video surveillance equipment and computer networks. As a company’s LAN (local area network) and all communication systems are tied into this cabling infrastructure it’s easy to see why it is so important to have it properly maintained.
A Brief History – Why do structured cabling standards exist?
In the early days of telecommunication, all related infrastructure was owned by the telephone company. Since they were responsible for managing all of the equipment there was no need for formal guidelines that included the owners of the commercial premises in regards to the cabling.
With the emergence of new technologies like the desktop computer, network devices and other new hardware a new problem arose. Early computing and telecommunication devices did not follow common cabling standards and were subject to proprietary styles of cabling and connectors. It took a lot of time to get these devices to communicate with one another effectively, the internal network infrastructure began to suffer. Tech companies had their own solutions which required lengthy downtime and proved to be costly to implement and troubleshoot. Some implementations required running all new cabling in order to meet the guidelines of a particular manufacturer.
To further complicate the problem, the breakup of Bell Systems and AT&T meant that AT&T would no longer provide cabling inside of commercial buildings, which until that time was all standardized due to them being the sole cabling installer for the country. With the split, new competitors arose which gave companies all over America the option of choosing different cabling companies, each with varying cabling practices. This of course can become an issue for maintenance costs if there are no standard cabling protocols that they all share.
With the dotcom bubble of the early 90s it became even more apparent how important structured cabling is. Many companies were switching over to fiber optic cabling for faster data transmission. Industry reports from this time reported that 70% of network downtime was caused by improper cabling systems. That much downtime can cost organizations anywhere from $1,000 to $50,000 an hour. Throughout the 90s, structured cabling standards saw several updates in order to keep up with demand (and it continues even today).
The Subsystems of Structured Cabling
As discussed above there was a movement by telecommunications companies to standardize cabling going to a commercial building. However, their job typically ends once the cabling arrives at that destination. So how is cabling handled at a business owner’s facility? How do cabling installers standardize the cabling infrastructure once inside?
Structured cabling consists of six components or subsystems. Each subsystem has its own part to play in delivering cabling through the premises – from delivering coaxial to the building outlet to running network cabling and patching it all down. Each subsystem contains a typical set of components to handle securing the cabling and cable management. By adhering to the standards of each subsystem contractors can create repeatable practices that are easy to troubleshoot, thereby reducing network downtime and lowering maintenance costs.
So what are the six subsystems of structured cabling?
Entrance Facilities
The entrance facility is where the service provider’s equipment enters the customer’s building. This involves having a conduit to receive the cables, either through the wall or floor (known as the service entrance) and into the entrance room. All cables are to be received and terminated at a single point, located within 50ft of the building’s penetration as outlined in the entrance facility guidelines in the ANSI/TIA-569. The point of termination is known as the Demarcation Extension Point or demarc.
Demarcation Extension Point (DEP)
The Demarcation Extension Point (DEP) is an important component of structured cabling. It is the point where the responsibility for telecommunications services shifts from the service provider to the customer. The DEP is used to separate voice and data cabling, allowing each to be managed independently. It also serves as a point of reference for troubleshooting and maintenance activities. By understanding what a DEP is and how it works, customers can ensure that their cabling infrastructure meets their needs and provides reliable service.
The Importance of Standardized Practices for Entrance Facilities
Since the entrance facility may need to be entered on a semi-regular basis by service providers there are further protocols to ease their ingress and egress from the facility. They should have a door that is easily accessible and swings outward if possible. These facilities should remain dedicated to their intended use only. That means electrical power distribution or being used as a storage space.
Entrance facilities play an important role in making sure networks run smoothly without experiencing delays due interruption caused by faulty connections coming from outside sources. When adhering to standard protocols they also help reduce risks associated with environmental factors, including electrical interference, water damage, extreme temperatures, dust accumulation and damage caused by rodents. Additionally, having easy access for service personnel reduces costs related to maintenance incurred each time something needs to be repaired. Having a secure entry prevents unauthorized people gaining physical access to the site thus providing an added layer of protection against unscheduled downtime.
The entrance facility should contain a cable rack to support the cabling that is to be distributed throughout the premises. Cables are then run on pathways towards the other access areas, secured by cable trays.
The following communications performance standards apply to entrance facilities:
- ANSI/TIA/EIA 568-A – This is the Commercial Building Telecommunications Cabling Standard.
- ANSI/EIA/TIA 569-A – The Commercial Building Standard for Telecommunications Pathways and Spaces.
- ANSI/TIA/EIA 607 – The Commercial Building Grounding and Bonding Requirements for Telecommunications.
- ANSI/TIA/EIA 607 – The Commercial Building Grounding and Bonding Requirements for Telecommunications.
Equipment Room
The equipment room is the subsystem where external cabling meets the internal cabling for the building. and is also where all telecommunications equipment is typically installed. The room is furnished with patch panels which carry the cabling to other components, namely connections for the backbone cabling, horizontal cabling and intermediate cross-section. The equipment room contains other IT equipment for networking such as the router, network switches, servers and the PBX.
Backbone Cabling
Backbone Cabling refers to the cabling that provides interconnection between the entrance facilities, equipment rooms and telecommunications rooms. This installation tends to run floor to floor, traveling vertically, however it can be run between IT facilities on the same floor. These vertical cabling installations are also referred to as riser cabling. Backbone cabling can also provide interconnection between buildings.
Backbone cabling is made up of two subsystems:
- Cabling Subsystem 2 – This refers to the backbone cabling between the horizontal cross-connect (HC) [Distributor A (DA)] and the intermediate cross-connect (IC) [Distributor B (DB)].
- Cabling Subsystem 3 – This is the cabling between an intermediate cross-connect (IC) and the main cross-connect (MC).
There are key components that make up backbone cabling. For floor and wall penetration, conduits and raceways are used. The wiring with this area one or a combination of coaxial, optical fiber and twisted-pair (Cat3, Cat5e, Cat6 or Cat6a). The optical fiber cabling may be multimode or single-mode.
Telecommunications Room
Telecommunications rooms are the access points for backbone cabling and building pathways. This is sometimes a dedicated facility but may also be part of a shared location for other utilities provided by several service providers. These service providers may include phone companies, cable operators, and wireless carriers. They are sometimes also relegated to telecommunications enclosures or closets.
What is the difference between a telecommunications enclosure and a telecommunications room?
A telecommunications enclosure is dedicated specifically to specific telecommunications components. Having a telecommunications enclosure reduces space constraints for the dedicated telecommunications room because you can integrate multiple services without needing an additional space. In a telecommunications room, the services are integrated and accessible from multiple devices (e.g. phones, fax machines, and computers). A telecommunications enclosure on the other hand is used by a single service provider to maintain control over the telecommunication services. This also allows the provider to offer integrated security systems for the exchange of confidential information (e.g. banking and financial information) through the telecommunication network for specific areas.
Another way to put it is that the key difference between the two is that a telecommunications enclosure is used where there is no need for multiple devices to access the services, whereas a telecommunications room is ideal for simultaneous access from multiple devices and services.
The telecommunications room not only contains the telecommunications equipment, it is where the termination of horizontal and backbone cabling are located. That means it will contain patch panels and patch cables for cross-connections.
Horizontal Cabling
Horizontal cabling refers to the cabling that runs between the telecommunications room or enclosure and the work area. Cabling exits the telecommunications areas then run to various drops distributed throughout the work area where they are terminated to be made available for equipment in those areas. It is common practice for telecommunications rooms and enclosures to be located on each floor. Should this be the case then the horizontal cabling is used specifically to supply the floor that it is on.
The horizontal cabling includes network cable and telecommunications outlets, a consolidation point (optional), mechanical terminations and patch cords cables.
The types of cabling involved in horizontal cabling:
- four-pair 100-ohm unshielded or shielded twisted-pair cabling – Cat5e, Cat6, Cat6a, Cat7 or Cat8;
- multimode optical fiber cabling, two-fiber
- single-mode optical fiber cabling
Work Area
The work area details any location housing user equipment that relies on cabling entering that area. This starts from the wall jack and also includes the cabling (ethernet, phone etc.) extending from it along with any user devices that they connect to. Each work area is served by a telecommunications room.
The Benefits of Structured Cabling for Commercial Properties
Having standardized implementations of structured cabling is important for ease of maintenance and cost effectiveness.
Structured Cabling is Easier to Manage
By using proper structured cabling subsystems, organizations can get authorized personnel to the right areas quickly and easily for maintenance routines and additional work. Adding more services or changing service providers incurs less risk of problems arising due to differences in cabling standards.
Structured Cabling is Cost-Effective
Commercial properties are able to recover from network downtime due to cabling issues much faster. This lowers maintenance fees for the unscheduled downtime while improving uptime during operational hours. Using proper doorways, conduits, enclosures and cable management also reduces damage to equipment.