When planning horizontal cabling, what is the maximum allowable distance that can be used?

Structured Cabling Standards and Details

These standards define how to lay the cabling in a star formation, such that all outlets terminate at a central patch panel (which is normally 19 inch rack-mounted), from where it can be determined exactly how these connections will be used. Each outlet can be ‘patched’ into a data network switch (normally also rack mounted alongside), or patched into a ‘telecoms patch panel’ which forms a bridge into a private branch exchange (PABX) telephone system, thus making the connection a voice port.

TIA/EIA-568-B defines a hierarchical cable system architecture, in which a main cross-connect (MCC) is connected via a star topology across backbone cabling to intermediate cross-connects (ICC) and horizontal cross-connects (HCC). Telecommunications design traditions utilized a similar topology, and many people refer to cross-connects by their older, nonstandard names: “distribution frames” (with the various hierarchies called MDF’s, IDF’s and wiring closets). Backbone cabling is also used to interconnect entrance facilities (such as telco demarcation points) to the main cross-connect. Maximum allowable backbone cable distances vary between 300m and 3000m, depending upon the cable type and use.

Horizontal cross-connects provide a point for the consolidation of all horizontal cabling, which extends in a star topology to individual work areas such as cubicles and offices. Under TIA/EIA-568-B, maximum allowable horizontal cable distance varies between 70m and 90m for twisted-pair cable types, depending upon patch cord length and gauge. Fiber optic horizontal cabling is limited to 90m. Optional consolidation points or transition points are allowable in horizontal cables, although many industry experts discourage their use.

Experience Make the Difference

Coupled with a detailed Assessment and Planning engagement, Action Communication Technology can plan and design a structured cabling infrastructure that will allow your business to cost effectively plan, install, and manage the complex cable and fiber infrastructure required by today’s networks.

ACT understands the high cost of physical plant change and implementation, and the challenges of effectively maintaining that physical plant for an increasingly mobile work force. Employee moves, adds, and changes can also be managed through this solution.

ACT’s broad experience in network cabling and fiber optic cabling plant design and implementation can assist businesses in deciding the best investment of scarce IT resources into new infrastructures. Designs are consistent with today’s business needs, characteristics, and requirements. Along with the information transfer needs of organizations, the solution incorporates planning, required facility modifications, installation planning and implementation, start-up and check out, testing and certifications, and on-site support services.

Structured Cabling Design

What exactly is Structured Cabling Design?

Structured Cabling is the design, documentation, and management of the lowest layer of the OSI network model-the physical layer. The physical layer is the foundation of any network whether it is data, voice, video or alarms, and defines the physical media upon which signals or data is transmitted through the network.

Approximately 70% of your network is composed of passive devices such as cable, cross-connect blocks, and patch panels. Documenting these network components is critical to keeping a network finely tuned. The physical medium can be copper cable (e.g., cat 3, cat 5E), coaxial cable, optical fiber, wireless, or satellite.

Key Components

Key components of the Structured Cabling design include the entrance facility, main equipment room, backbone cable, backbone pathway, Intermediate Distribution Frame (IDF), and horizontal distribution system. We can show you how to develop an online inventory and management system that will let you take control of these critical infrastructure resources.

New buildings require voice, data, and video wiring and electronics facilities within the building to support the newest forms of telecommunications. A series of standards has been developed to provide guidance in designing new buildings and remodeling older facilities. The list of facilities that need to be taken into consideration are building entrance facilities, entrance wiring closets, floor wiring closets protection and grounding, backbone raceways, horizontal raceways, backbone wiring, and horizontal wiring. A more definitive document exists which identifies the considerations and options for architectural and engineering areas supporting telecommunications within a building. The document should be used for design activities, as the following material is a summary.

Entrance facilities

Cabling must enter the building underground and usually within 4 inch conduits. Three or more of the conduits will be required to connect an entrance wiring closet to the nearest manhole or other location with telecommunications facilities. Consideration is required for the type of conduit, depth of bury, separation from other conduits bends in the conduit, conduit capping and seals, manhole sizes, and pull lines.

Entrance wiring closet

Exclusive use of a room for placement of electronics and terminations of cable of many types, which supply the building with telecommunications. Security is required and the room cannot be shared with other functions in the building. Considerations for the facility are floor weight load factors, water avoidance, lighting, electrical access, room size, electrical grounding, HVAC, and location near the building entrance facility.

Floor wiring closet

Exclusive use of a location on each floor to facilitate the electronics and cabling distribution for the floor. If the floor is large enough, with long cable runs, more than one room may be required on each floor. Security requires that the room not be shared with other building functions. Considerations for the facility are floor loading factors, water avoidance, ceilings and walls, fire door, lighting, electrical access, room size, electrical grounding, HVAC, floor location, and cable run maximum lengths.

Backbone raceways

Backbone raceways are a series of accesses that connect the entrance wiring closet to the various floor wiring closets. These paths permit cable to be placed between the floors. They may be slots, sleeves, conduits or trays and racks in which cables may be routed for support and protection. Considerations are the size, quantity, and seals. If conduits or sleeves are used, the 4 inch size is preferred. The in depth document contains a table giving the number of paths needed, based upon building size.

Horizontal raceways

The horizontal raceway carries the cable from the floor wiring closet to the various rooms on the floor. There are many types of systems available today and the pros and cons of each are covered in the detail document. Ceiling trays used in conjunction with utility columns and conduit paths are the preferred method of horizontal distribution. The nature of the building usage may justify another type of cable path. Considerations for the path include bends or curves, size, conduit run lengths, and outlet boxes.

• Main Equipment Room
• Cables
• Cross-connecting blocks
• Patch panels
• Jumpers
• Connecting hardware

Pathways (supporting structures such as cable trays, conduits, and hangers that support the cables from the Intermediate Distribution Frame (IDF) to the work areas)

Why Document Your Cable Plant?

Your network is one of your company’s most valuable assets. It’s the central nervous system of your organization and it’s growing along with your network management problems. Your challenge is to harness the power of exploding technology and make it work for you. Every minute spent tracking data, reconfiguring your cable plant or searching for the source of a problem means loss of time and productivity and loss of profit. Cable plant documentation software can help maintain the integrity of the network by tracking the continuity through equipment, patch cords, cross-connects, connectors, cables, and outlets. It encompasses the design and maintenance of the cable plant. Cable plant documentation can be an ally against the ravages of system downtime, giving you the power to configure your cable plant so you have fewer network problems.

Cable Plant Documentation Can:

• Reduce the time it takes to modify the original installation.
• Minimize network downtime.
• Increase the life of a cabling plant.
• Reduces the number of technicians needed to handle problems.

Let us work with you to develop a Network Management system you can use to manage all of your cable plant, including all the connectivity, connectors, pathways, and device relationships to truly visualize and understand your network’s infrastructure. Let’s get started today, just give us a call.

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