Guide to Network Cabling
Fundamentals
Chapter 4
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Chapter 4 - Installing Cables and
Supporting Structures
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Identify the different pathways and why they are
necessary
Understand the layouts of equipment rooms and
telecommunications rooms
Discuss proper cable installation procedures
Identify good cable management practices and
understand their importance
Document your network
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Pathways
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Pathways provide the means for placing cables
between the equipment room, the
telecommunications rooms, and work areas
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Two types of pathways exist: horizontal and vertical
Choosing proper pathway components at the design
stage makes it easier to perform cable-related work and
maintenance later
Generally, cabling choices do not dictate pathway
choices; the pathway must accommodate all standardscompliant cabling and allow for necessary changes later
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Pathways
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Horizontal pathway systems:
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Horizontal pathway systems are designed to distribute,
support, and provide access to the horizontal cabling,
which is the cable that links the distribution field of the
cross-connect system in the telecommunications room to
the telecommunications outlet/connector in each work
area
The horizontal distribution system includes the pathway
itself (cable trays, conduit, and J-hooks),
as well as related spaces such as pull boxes, splice
boxes, and consolidation points that provide
access to the cable and connecting hardware
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Pathways
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Horizontal pathway systems (cont.):
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There are a number of methods for routing horizontal
cables to the work area; one of the most common
methods is zone cabling, in which cable bundles are run
to a particular area from the telecommunications room
along J-shaped hooks suspended in a plenum or above a
ceiling
Upon reaching the zone, cables are fanned out and
dropped though interior walls, support columns, or
raceways, and then terminated at the telecommunications
out/connector (work area outlet)
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Pathways
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Horizontal pathway systems (cont.):
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An underfloor duct system is a network of metal raceways
that are embedded in concrete
The underfloor duct system includes the main feeder
ducts, which carry the cables from the
telecommunications room to the distribution area, which in
turn carry the cables to a specific floor area
The system also includes junction boxes, which permit the
changes in the direction of the cable, and a splice box,
which is an opening in the system providing access for
making connections
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Pathways
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Horizontal pathway systems (cont.):
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Conduits are pipes that cable is placed in and pulled
through; they are installed from telecommunications
rooms to work area outlets in floors, walls, columns
The following conduits are rated as suitable for buildings:
rigid metal made of steel; intermediate metal conduit;
electrical metal tubing; PVC conduit
When using conduit for your pathways, observe these
design and installation guidelines: run cable in the most
direct route; continuous sections no longer than 30 m and
no more than two 90° angles; each conduit must be
bonded to ground
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Pathways
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Horizontal pathway systems (cont.):
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Cable tray systems are commonly used as distribution
systems for cabling within a building
They are often preferred to conduit and raceways
Cable trays are prefabricated structures that route and
support telecommunications or power cables
Cable trays are open and equipped with sides that allow
cable to be laid within the tray’s entire length
When cable trays are used in the ceiling area, conduit
should be provided from the end of the tray to the
telecommunications outlets
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Pathways
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Horizontal pathway systems (cont.):
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Access (raised) floors sit above the existing subfloor and
provide access to the space under its panels;
Access floors are most often found in computer and
equipment rooms
There are two basic types of access flooring: standard
and low-profile floors
Access floors consist of the following components: steel
footing which rest on the subfloor; pedestals support and
interlock with lateral bracing and panels; modular floor
panels rest on bracing and pedestals
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Pathways
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Horizontal pathway systems (cont.):
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To distribute horizontal cable from the telecommunications
room to the work area, ceiling distribution systems use the
open, interstitial space between the structural ceiling and
an accessible grid ceiling hanging below it
Guidelines for ceiling distribution include: the ceiling
space is only used for horizontal cabling serving the floor
below; the areas used are fully accessible from the floor
below; the ceiling tiles are removable
The ceiling zone method is commonly used
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Pathways
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Vertical pathways:
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Vertical pathways are the spaces that provide distribution
access of backbone cabling between communications
rooms in multistory buildings
Follow these vertical pathway design requirements: the
pathways should be stacked above each other and be
accessible from each floor; they must contain at least
three 4-inch conduits, or sleeves; the pathways should
have a 100-watt fixture with a bulb and a 20-amp, 100-volt
electrical outlet, and the pathway entrances should be
secured with a mortised combination lock
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Pathways
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Vertical pathway installation guidelines:
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All installation personnel have adequate preparation
Establish adequate spacing between cables and any
other facilities that use the same/adjacent pathway
Remove any hazards from each floor
Complete all necessary preparations before install
Choose the raising or lowering method and then set up all
necessary associated hardware, including shoes,
sheaves, and winches
Set up safety measures such as perimeters, cones, and
reel and sheave blocks
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Pathways
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Vertical pathway installation guidelines (cont.):
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When lowering cable, position the cable reel away from
the opening; use a shoe or sheave to direct the cable into
the opening; ensure that adequate braking measures are
set up; secure the cable once it is in position, starting at
the bottom level
When raising cable, secure an opening sheave and power
winch; lower the pulling line from the top floor; ensure that
adequate braking measures are set up; use the
manufacturer’s pulling eye or a core hitch; secure the
cable once it is in position, starting at the bottom level
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Pathways
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Choosing the right cable and documenting it
before installation involves:
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Creating a detailed floor plan that identifies every
relevant piece of equipment
Identifying floor plan elements with a unique ID
Before running the cable, consulting the floor plan for the
cable ID number and apply this ID to the end of the
cable you are pulling and to the box or reel from which
the cable is fed
Understand the information on the cable jacket
Record the length of each cable run
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Equipment Rooms and
Telecommunications Rooms
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Equipment rooms and telecommunications rooms
in a building act as junctions between the
backbone and horizontal pathways
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Both may house such items as the main distribution
frame, small telephone systems (PBXs), secondary
voltage protection, active voice and data
telecommunications equipment, termination fields, and
cross-current wiring, which connects a circuit from one
facility to another in a network
Standard ANSI/EIA/TIA-569-A provides a design guide
for telecommunications/equipment rooms
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Equipment Rooms and
Telecommunications Rooms
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Equipment rooms:
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The equipment room houses the main distribution frame,
a steel-bar framework that typically holds the phone
company’s central office protective devices, serves as
the major cross-connect point for the central office lines
and the customer’s wiring, and interconnects loop cable
pairs and line-equipment terminals on a switching
system
This room is often appended to the entrance facility or
computer room to allow sharing of air conditioning,
security, fire control, and lighting
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Equipment Rooms and
Telecommunications Rooms
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Telecommunications rooms:
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The telecommunications closet on each floor provides
the junction point between the backbone and horizontal
pathways; these rooms contain active voice/data
telecommunications equipment, termination fields, and
cross-connect wiring
More than one telecommunications closet per floor is
required if the distance to a work area exceeds 100 m,
or if the floor area served exceeds 10,000 sf
Requirements for power, lighting, air conditioning and
access are the same as for equipment rooms
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Cable Installation Guidelines
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The ANSI/EIA/TIA-569-A standard provides
instructions and guidelines for ensuring successful
installations:
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Conduit capacity, the number of cables it can hold,
depends on the size of the cables and the conduit
Typically, the conduit size for outlets of data and voice
cables is 21 mm
In general, high- and low-signal cables should not be run
in the same conduit; in addition, the NEC forbids the
installation of telecommunications cables in the same
conduit as power cables
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Cable Installation Guidelines
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Instructions and guidelines (cont.):
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There are maximum recommended pulling tensions for
conductors since copper will begin to permanently
stretch under approximately 15,000 pounds per square
inch
During installation, the total pulling tension must be
equally distributed among all conductors
The following factors determine pull force: cable type,
number of pairs and quantity of cable; conduit type, size,
and length; number and configuration of conduit bends;
use of cable lubricants
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Cable Installation Guidelines
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Instructions and guidelines (cont.):
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Every ceiling distribution system must properly support
cables from the telecommunications room to the work
area it serves
Ceiling conduits, raceways, cable trays, and cabling
must be suspended from or attached to the structural
ceiling or walls, using hardware specifically designed to
support their weight
Where building codes permit cables to be placed in
suspended ceilings without conduit, ceiling zone
distribution pathways may consist of cable trays
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Cable Installation Guidelines
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Instructions and guidelines (cont.):
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Cable bend radius is the amount a cable can bend
before it is damaged or its performance is impaired;
maintaining correct bend radius is critical when
terminating wire pairs and creating service loops
The minimum bend radius for cable (six or fewer pairs) is
four times the cable’s outside diameter
Cable stress is avoided by: supporting suspended
cables every four to five feet; fastening cable ties; not
exceeding pulling tensions during installation; not
allowing cables to snag during installation
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Cable Installation Guidelines
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Instructions and guidelines (cont.):
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Proper cable termination leads to communications
systems that require little or no service
Terminate horizontal and backbone cables on appropriate
connecting hardware; since these cables are always
terminated on separate connectors, use patch cords or
jumpers
To prevent the effects of improper termination practices:
remove only as much cable jacket as needed for
termination and trimming; follow the manufacturer’s
instructions; minimize untwisting
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Cable Management Practices
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Cable system performance is degraded by:
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Connector terminations
Cable installation and management
Use of cross-connect jumpers and patch cords
Multiple connections in close proximity
It is important to follow proper guidelines to
manage horizontal and backbone cables, crossconnects, vertical and horizontal pathways, and
ceiling and zone distribution
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Cable Management Practices
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Horizontal and backbone cable management:
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Be especially compliant to cable bend radius and pullforce guidelines during cable installation
In both the cable pathways and telecommunications
room, use appropriate cable routing and dressing fixtures
to organize and manage the cable types
This type of management can eliminate cable stress
caused by: tension in suspended cable; tightly clinched
cable bundles, which damage jackets; twisting cable
jackets during installation
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Cable Management Practices
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Cross-connect management:
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The two most common cross-connect systems are the
BIX and the 110 systems
Keep voice and data fields separate
Use color-coding to identify termination areas
Avoid patch cord or jumper slack
Manage cross-connects by following these precautions:
After each cross-connection is completed, eliminate patch
cord and jumper slack; be especially aware of patch cord
bend radius for twisted-pair and fiber
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Cable Management Practices
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Vertical and horizontal pathway management:
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Vertical cable management channels made of copper
provide cable and patch cord protection and routing
space; those made of fiber contain uniquely designed wire
guides to maintain bend radius
Vertical cable management channels can be easily
fastened on either side of the racks
Horizontal cable management channels also provide
patch cord protection and routing space; they are usually
equipped with a front-cover panel fastened with plastic
rivets
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Cable Management Practices
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Ceiling zone distribution management:
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Perform these steps: place cables into the zone pathway;
leave sufficient slack to reach work area outlets; run all
cables to the center point of their zone and from there,
distribute cables to work areas; support all cables with
Velcro cable ties; coil cable not in service; label cables
and pathways
Cable management and ANSI/EIA/TIA-606
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ANSI/EIA/TIA-606 defines administration as a necessary
foundation for effective cable management and reliable
infrastructure
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Documenting Your Network
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Good network documentation accounts for:
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A diagram of the physical network
The topologies and network architecture in use
Protocols and logical addressing schemes
Operating systems and directory services
Cabling standards and network conventions
The documenting of manufacturers and vendors
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Chapter Summary


Cabling pathways provide the means for placing cables
between the equipment room, the telecommunications
rooms, and the work areas. These pathways can be
horizontal or vertical
A common method of horizontal cabling is zone cabling, in
which cable bundles are run to a particular area from the
telecommunications room along J-hooks suspended
above a plenum ceiling. Upon reaching the zone, cables
are fanned out and dropped through interior walls, support
columns, or raceways, and terminated at the work area
outlet
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Chapter Summary

The equipment room and telecommunications
rooms in a building act as junctions between the
backbone and horizontal pathways. Both rooms
may house such items as the main distribution
frame, PBXs, secondary voltage protection,
active voice and data telecommunications
equipment, termination fields, and cross-connect
wiring
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Chapter Summary
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Cabling installations begin with the placement of
all the large backbone and intrabuilding cables,
followed by the smaller horizontal cabling, and
then the interconnect cables. The ANSI/EIA/TIA569-A standard provides important instructions
for ensuring successful installations, including
information on conduit capacity, cable pulling
tensions, pathway and cable support, bend
radius, cable stress, termination practices, and
jackets
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Chapter Summary
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Connector and cable components that meet
transmission performance requirements are
crucial to your installed cabling system, but they
do not ensure success. Performance may be
degraded by poor or improper cabling practices
related to connector terminations, cable
installation and management, use of crossconnect jumpers and patch cords, and multiple
connections in close proximity
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Chapter Summary
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Make your network documentation more effective
by including a compete network diagram, along
with specific information about hardware,
software, topologies, conventions, cabling
standards, and configuration. The more you
document the network, the better equipped
everyone will be to work on it. Remember to keep
this documentation up to date; incorrect
information can be worse than none at all
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