Structured Cabling Supplement

Structured cabling systematically connects all parts of the LAN starting at the demarcation point, working through the various equipment and telecommunications rooms, and continuing to t

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Structured Cabling Supplement

Cisco Networking Academy Program CCNA 1: Networking Basics v3.0

INSTALLATION PROCESS FINISH PHASE

THE CABLING BUSINESS Completing this material and the associated labs will provide a broad introduction to all facets of structured cabling installation

Structured cabling systems provide insight into the rules and subsystems of structured cabling for a localarea network (LAN) A LAN is defined as a single building or group of buildings in a campus environment in close proximity to one another, typically less than two square kilometers or one square mile Structured cabling

systematically connects all parts of the LAN starting at the demarcation point, working through the various equipment and telecommunications rooms, and continuing to the work area The issue of scalability is also addressed The learning objectives for Structured Cabling Systems follow:

1.1 Rules of structured cabling for LANs 1.2 Subsystems of structured cabling 1.3 Scalability

1.4 Demarcation Point 1.5 Telecommunications and Equipment Rooms 1.6 Work areas

1.7 MC, IC, and HC

Structured Cabling Standards And Codes introduces the standards

setting bodies that put forth the guidelines that cabling specialists work by Important information about these international standards organizations is introduced

The learning objectives for Structured Cabling Systems follow:

2.2 European Committee for Electrotechnical Standardization (CENELEC)

2.3 International Organization for Standardization (ISO) 2.4 U.S Codes

2.5 Evolution of Standards

Safety is an important chapter containing information often

overlooked in coverage of low voltage telecommunications wiring Students not accustomed to working in the physical workplace will benefit from the labs and training in this section

The learning objectives for Safety follow:

3.1 Safety Codes and Standards for the United States 3.2 Safety Around Electricity

3.3 Lab and Workplace Safety Practices 3.4 Personal Safety Equipment

Tools Of The Trade, as with any craft, are often what makes the

difference between a hard job with mediocre results and a simple job with outstanding results This module gives the students hands-on experience with several of the tools used by telecommunicationscabling installers to have professional results

The learning objectives for Tools of the Trade follow:

4.1 Stripping and Cutting Tools 4.2 Termination Tools

4.3 Diagnostic Tools 4.4 Installation Support Tools

Installation Process contains the elements of an installation, starting

from the rough- in phase where the cables are pulled into place Riser (backbone) cables are discussed, as are the fire stops used where a cable passes through a fire rated wall Copper terminations are covered, as are wall adapters and other fixtures

The learning objectives for Installation Process follow:

5.1 Rough-In Phase 5.2 Vertical Backbone and Horizontal Cable Installation 5.3 Fire-stops

5.4 Terminating Copper Media

5.5 The Trim Out Phase

Finish Phase is the point at which installers test and in some cases

certify their work Testing assures that all cables are properly routed

to their appointed destination Certification is a statement of the quality of the wiring connection certifying that it meets the requirements defined by the Industry Standards

The learning objectives for Finish Phase follow:

6.1 Cable Testing 6.2 Time domain reflectometer (TDR) 6.3 Cable Certification and Documentation 6.4 Cutting over

The Cabling Business requires its share of attention, as does the

business side of any other enterprise Before cables can be installed, there must be a bid Before there can be a bid there must be a request for a proposal, and walk-throughs to determine the precise scope of the work Documentation both to describe the project and to show how it was actually built may be required Licenses may be required

to perform the work, and perhaps union membership All projects must be performed in a timely manner, with minimal waste of time or materials This is usually a job for project planning and using

program management applications

The learning objectives for Cabling Business follow:

7.1 Site Survey 7.2 Labor Situations 7.3 Contract Revision and Signing 7.4 Project Planning

7.5 Final Documentation

Lab exercises give the student the opportunity to practice the manual skills portion of structured cabling installation The Case Study is designed to give the student a hands-on opportunity to participate in the design of a structured cabling system for a fictitious software development company that is occupying a new three-story building and requires it to be built out

1 Structured Cabling Systems

1.1 Rules of structured cabling

Structured cabling is a systematic approach to cabling It is a method for creating an organized cabling system that can be easily

understood by installers, network administrators, and any other technicians that deal with cables

The following three rules will help ensure that the structured cabling design projects are both effective and efficient:

Look for a complete connectivity solution - An optimal solution for network connectivity includes all the systems that are designed to connect, route, manage, and identify structured cabling systems A standards-based implementation will help to make sure that both current and future technologies can be supported Following standards will make sure that the project will deliver performance and reliability over the long term

Plan for future growth – The number of cables installed should meet these future requirements as well Category 5e, Category 6, and fiber-optic solutions should be considered where feasible to ensure that future needs will be met It should be possible to plan a physical layer installation that works for ten or more years

Maintain freedom of choice in vendors - A non-standard compliant system from a single vendor may make it more difficult to make any moves, adds, and changes to the cabling infrastructure at a later time Even though a closed and proprietary system may be less expensive initially, this could end up being much more costly over the long term

Web Link:

http://www.panduitncg.com/NCG_SYSSOL/ncg_syssol_pm/ncg_syssol_pm_markets/Finance/rules.asp

1.2 Subsystems of structured cabling

Figure 1 Subsystems of Structured Cabling

There are seven subsystems associated with the structured cabling system (See Figure 1) Each subsystem performs certain functions to provide voice and data services throughout the cable plant

■ Demarcation point (demarc) within the entrance facility (EF) in the equipment room

■ Equipment Room (ER)

■ Telecommunications room (TR)

■ Backbone cabling - also known as vertical cabling

■ Distribution cabling - also known as horizontal cabling

■ Work area (WA)

■ Administration The demarc is where outside service provider cables interface with the customer’s cables in the facility Backbone cabling is the the feeder cables that are routed from the demarc to the Equipment Rooms and then on to the Telecommunications Rooms throughout the facility Horizontal cabling distributes cables from the

Telecommunication Rooms to the work areas The telecommunications rooms are where connections take place to provide a transition between the backbone cabling and horizontal cabling

These subsystems make structured cabling, by nature, a distributed

cabling infrastructure that properly routes, protects, identifies and terminates the copper or fiber media is absolutely critical for network performance and future upgrades

1.3 Scalability

A LAN that can accommodate future growth in size is referred to as being scalable It is very important to plan ahead when estimating the number of cable runs and cable drops in a work area It is always easier to ignore extra installed cables than to not have them when they are required

In addition to pulling extra cables in the backbone area for future growth, it is also common practice to pull an extra cable to each workstation or desktop for future use This gives protection against pairs that may fail on voice cables during installation, and it also provides for expansion It is also a good idea to provide a pull string when installing the cables to make it easier for adding cables in the future Whenever new cables are added, a new pull string should also

be added

1.3.1 Backbone Scalability

To determine how much extra copper cabling to pull, first determine the number of runs that are needed now, and add some extra, say about 20%

Another way to obtain this reserve capability is to use fiber-optic cabling and equipment in the building backbone Updating the termination equipment (by inserting faster lasers and drivers, for example) can accommodate fiber growth

1.3.2 Work Area Scalability

Figure 1 Allow for Growth

machines, laptops, or another user in the work area can all require their own network cable drops

Once the cables are in place, use multi-port wall plates over the jacks There are many types of configurations that are possible for either modular furniture or partition walls In addition, use jacks that are color-coded to make it easier to identify types of circuits

Administration standards require that every circuit is clearly labeled

to assist in connections and troubleshooting

A new technology that is becoming very popular is Voice over Internet Protocol (VoIP) This technology allows special telephones

to use data networks when placing telephone calls A great advantage

to this technology is the ability to avoid costly long distance charges

by using this service over existing data network connections Other devices like a printer or computer can be plugged into the IP phone Even if these types of connections are planned, enough cables should

be installed to allow for growth Especially considering that the growth will include integrated IP video traffic as well in the not too distant future

To accommodate the changing needs of users in offices, it is recommended to provide at least one additional spare cable to the work area outlet Offices may change from single user to multi-user spaces In these cases, a work area can become inefficient if only one set of communication cables were pulled Assume that every work area could accommodate multiple users in the future (See Figure 1) Traditionally, business networks were built to support delivering services such as telephone, data, video, surveillance, etc Each service required a different infrastructure consisting of hardware, software and media to deliver and manage the service A trend in today’s network infrastructure centers on the convergence of voice, data and video traffic over one network infrastructure This profound change creates a network cabling infrastructure that is even more important

to your business

1.4 Demarcation Point

Figure 1 Demarcation Point

The demarcation point (demarc), provides the point at which outdoor Service Provider cabling interfaces with the intra-building backbone cabling (See Figure 1) It represents the boundary between the service provider's responsibility and that of the customer In many buildings, this location is the same point of presence (POP) for other utilities such as electricity and water

The service provider is responsible for everything from the demarc out to the service provider's facility Everything from the demarc into the building is the customer's responsibility

The local telephone carrier is typically required to terminate cabling within 15 m (49.2 ft) of building penetration and to provide primary voltage protection This is usually installed and provided by the service provider

The Telecommunications Industry Association (TIA) and Electronic Industries Association (EIA) develop and publish standards for many industries including the cabling industry To ensure that the cabling installation is safe, installed correctly, and retains performance ratings, these standards should always be followed when performing any voice or data cabling installation or maintenance

The TIA/EIA-569-A standard specifies the requirements for the

than 2000 usable square meters, a locked, dedicated, and enclosed room is recommended

The following are general guidelines when setting up a demarcation point space:

■ Allow one square meter (10.7 ft²) of plywood wall mount for each 20 square meter (215.3 ft²) area of floor space

■ The surfaces where the distribution hardware is mounted must be covered with fire-rated plywood or plywood that is painted with two coats of fire retardant paint

■ Either the plywood or the covers for the termination equipment should be colored orange to indicate the Point of Demarcation

1.5 Telecommunications and Equipment Rooms

Figure 1 Telecommunications Room

Figure 2 Panduit Distribution Rack

After the cable enters the building through the demarc, it travels to the Entrance Facility (EF), which is usually in the Equipment Room (ER) The equipment room is the center of the voice and data network An equipment room is essentially a large

telecommunications room that may house the main distribution frame, network servers, routers, switches, the telephone PBX, secondary voltage protection, satellite receivers, modulators, high speed Internet equipment, and so on The design aspects of the equipment room are specified in the TIA/EIA-569-A standard

In larger facilities the equipment room it may feed one or more Telecommunications Rooms (TR) which are distributed throughout the building A Telecommunications Room, is an area within a building that houses the telecommunications cabling system equipment (See Figure 1) for a particular area of the LAN such as a floor or part of a floor This includes the mechanical terminations and/or cross-connect devices for the horizontal and backbone cabling system It would also be common for departmental or workgroup switches, hubs, and possibly routers to be located in the TR

A wiring hub and patch panel in a TR may be mounted to a wall with

a hinged wall bracket, a distribution rack (See Figure 2), or a full equipment cabinet

If the choice is a hinged wall bracket, the bracket must be attached to the plywood panel that covers the underlying wall surface The purpose of the hinge is to allow the assembly to swing out so that technicians can easily access the backside of the wall Care must be taken, however, to allow 48 cm (18.9 in) for the panel to swing out from the wall

55.9 cm (22 in) floor plate, used to mount the distribution rack, will provide stability, and will determine the minimum distance for its final position

If the patch panel, hub and other equipment are mounted in a full equipment cabinet, they require at least 76.2 cm (28.6 in) of clearance

in front, in order for the door to swing open Typically, such equipment cabinets are 1.8 m high x 74 m wide x 66 m deep (5.9 ft

x 2.4 ft x 216.5 ft)

Equipment must be placed into equipment racks with care

Considerations include whether or not the equipment uses electricity, cable routing, cable management, and ease of use For example, a patch panel would not be placed high on a rack if a significant number of changes were to take place after the systems were installed Convenience of use is a large consideration when planning the equipment layout Heavier equipment such as switches and servers should be placed near the bottom of the rack for stability Scalability is also a consideration in an equipment layout, as future growth should be accommodated Space should be left on a rack for future patch panels, or floor space left for future rack installations in

an initial layout

Proper installation of equipment racks and patch panels in the TR will allow easy changes and modifications to the cabling installation in the future This is important when considering the design and layout of the work areas

1.6 Work areas

Figure 1 Work Areas

The area serviced by an individual telecommunications room is usually one floor or part of a floor in a building (See Figure 1) The size of the TR is dependent upon the size of the area being served One TR can accommodate up to 1000 square meters (10,000 sq ft) If the area to be served exceeds that, then another TR needs to be provided for that floor or area The floor space served by the TR is divided into individual work areas This is where the occupants of the building will normally work and interact with their

telecommunications equipment such as telephones, computers, printers, fax machines, etc A work area is typically 10 square meters (100 sq ft.)

The maximum distance for a cable from the termination point in the

TR to the termination at the Work Area outlet must not exceed 90 meters (295 ft.) This 90 meter maximum horizontal cabling distance

is referred to as the Permanent Link Each work area must have at least two cables, one for data and the other for voice As previously discussed, accommodations for other services and future expansion must also be considered

Cables cannot usually be strung across the floor, but rather usually ride in wiring management devices such as trays, baskets, ladders, and raceways These devices route the paths of the cables above workspaces, often in the plenum areas above suspended ceilings This means that the height of the ceiling times two (once up to the wiring management device, once back down) must be subtracted from the proposed work area radius

In addition, ANSI/TIA/EIA-568-B specifies that there can be 5 meters (16.4 ft) of patch cord to interconnect equipment patch panels, and 5 meters of cable from the cable termination point on the wall to the telephone or computer This additional maximum of 10 meters of patch cordage added to the Permanent Link is referred to as the Horizontal Channel The maximum distance for a Channel is 100 meters, the 90 meter maximum Permanent Link plus 10 meters maximum of patch cords

1.6.1 Servicing the Work Area

Figure 1 Servicing the Work Areas

Patching is done when connectivity changes are needed often or are foreseen It is much easier to simply patch the cable from the work area outlet circuit to a different location in the TR than it would be to remove terminated wires from connected hardware and re-terminate them to another circuit Patch cords are also used to connect

networking equipment to the cross-connects in a TR Patch cords are limited by the TIA/EIA-568-B.1 standard to five meters

A uniform wiring scheme must be used throughout a patch panel system All jacks and patch panels should be wired using the same wiring plan If the T568A wiring plan is used for the information outlets or jacks, T568A patch panels should be used The same is true for the T568B wiring plan

Patch panels can be for UTP (Unshielded Twisted Pair), STP (Shielded Twisted Pair), or used in enclosures for fiber-optic connections The most common patch panels are for UTP These patch panels use RJ-45 jacks Patch cords with RJ-45 plugs connect

to these ports

There is still a fault with this plan, however There is no provision to keep authorized maintenance personnel from installing unauthorized patches or installing an unauthorized hub into a circuit

There is an emerging family of automated patch panels, however, which can provide extensive network monitoring in addition to simplifying the provisioning of moves, adds, and changes These patch panels normally provide an indicator lamp over any patch cord that need to be removed, and then once the cord is released, provide a second light over the jack to which they should be re-affixed In this way the system can automatically guide a relatively unskilled employee through moves adds and changes In Figure [1], the Panduit

PanView management system automatically flags operators to the location of jacks that need to be repatched

The same mechanism that detects when the operator has moved a given jack works also to detect when a jack has been pulled Thus, an unauthorized resetting of a patch can trigger an event in the system log, and if need be trigger an alarm For instance, if a half-dozen wires to the work area suddenly show up as being open, and it is 2:30

in the morning, likely this is an event worth looking into, as theft may

be occurring

This is actually a Physical Layer implementation of enterprise monitoring software For years, systems using SNMP and RMON packets have offered the ability to detect the conditions of network computers from a central monitoring site For instance, if the number

of hard disk clusters marked as bad is creeping upward at an increasing rate, then it is likely that a hard disk failure may be imminent Network monitoring software can detect this condition and summon a service person to attend the failing machine before the failure occurs This makes it much easier to back up and restore the system, minimizing down time and preventing data loss

1.6.2 Types of patch cables

Figure 1 UTP Patch Cable

Patch cables (See Figure 1) come in a variety of wiring schemes The most common, the straight through, has the same wiring scheme on both ends of the cable In other words, pin 1 on one end is connected

to pin 1 on the other end Pin 2 on one end corresponds to pin 2 on the other, and so on These types of cables are used to connect PCs to

a network hub or switch

When connecting a communications device, such as a router, switch,

or server, to a network hub or another switch, a crossover cable is usually used Crossover cables use the T568A wiring plan on one end

Lab 1: Examination of Termination Types

1.6.3 Cable management

Figure 1 Panduit Rack-Mounted Vertical and Horizontal Cable Management System

Cable management devices are used for routing cables and providing

a neat and orderly path for the cables and to assure minimum bend radius is maintained Cable management also eases cable additions and modification to the wiring system There are many options for cable management in the TR Cable baskets can be used when an easy, lightweight installation is needed Ladder racks are often used when heavy loads of bundled cable need to be supported Different types of conduits can be used to run cable inside walls, ceilings, floors, or when they need to be shielded from external conditions Cable management systems are used vertically and horizontally on telecommunications racks to distribute cable in a neat and orderly fashion (See Figure 1)

1.7 MC, IC, and HC

Figure 1 MC, HC, and IC Planning

Most networks have more than one TR for various reasons First of all, a medium or large network is usually spread over many floors or buildings in campus environmemts A minimum of one TR is needed for each floor of each building (See Figure 1)

Secondly, media can only carry a signal so far before the signal starts

to degrade or attenuate Therefore, TRs are located at defined distances throughout the LAN to provide interconnects and cross-connects to hubs and switches to assure desired network performance

At these points, equipment such as repeaters, hubs, bridges, or switches are needed to regenerate the signal and then send it on This equipment is stored in some type of TR whether it is a small room or even just a cabinet

Not all TRs are equal The primary TR, called the main cross-connect (MC), is the center of the network This is where all the wiring originates and where most of the equipment is housed The intermediate cross-connect (IC) is connected to the MC and may house the equipment for a building on a campus The horizontal cross-connect (HC) provides the cross-connect between the backbone and horizontal cables on a single floor of a building

1.7.1 Main cross-connect (MC)

The MC is the main concentration point of an entire building or campus The MC is in effect the primary TR It is the room that controls the rest of the TRs (the ICs and HCs) in a building or campus In some networks, it is the place where the inside cable plant

All ICs or HCs are connected to the MC in a star topology Backbone,

or vertical cabling is used to connect those ICs and HCs located on other floors Where the entire network is confined to a single multi-story building, the MC is usually located on one of the middle floors

of the building, even though the demarc might be located in an entrance facility on the first floor or in the basement

For campus networks that comprise multiple buildings, one building typically houses the MC and each individual building typically has its own version of the MC called the intermediate cross connect (IC) that connects all the HCs within the building The IC allows the extension

of backbone cabling from the MC to each HC

There may only be one MC for the entire structured cabling installation The MC feeds the ICs, and each IC feeds multiple HCs There can be only one IC between the MC and any HC

The backbone cabling (red lines in the figure) runs from the MC to each of the ICs The ICs are located in each of the campus buildings, and the HCs serve work areas Horizontal cabling, running from the HCs to the work areas, is represented by the black lines

1.7.3 Backbone cabling

Any cabling installed between the MC and another TR is known as backbone cabling The difference between horizontal and backbone cabling is clearly defined in the standards Backbone, or vertical, cabling consists of the backbone cables, intermediate and main cross-connects, mechanical terminations, and patch cords or jumpers used for backbone-to-backbone cross-connection Backbone cabling includes:

■ TRs on the same floor (MC to IC, IC to HC)

■ Vertical connection (risers) between TRs on different floors (MC

to IC)

■ Cables between TR and demarcation point

■ Cables between buildings (inter-building) in a multi-building campus

The maximum distances for cabling runs vary from one type of cable

to another For backbone cabling, the maximum distance for cabling runs can also be affected by how the backbone cabling is to be used

To understand what this means, assume that a decision has been made

to use single-mode fiber-optic cable for the backbone cabling If the networking media were to be used to connect the HC to the MC, then the maximum distance for the backbone cabling run would be 3000 m (9,842.5 ft)

At times the maximum distance of 3000 m (9,842.5 ft) for the backbone-cabling run must be split between two sections, as when the backbone cabling is to be used to connect the HC to an IC and the IC

to the MC When this occurs, the maximum distance for the backbone

cabling run between the HC and the IC is 300 m (984 ft) The maximum distance for the backbone cabling run between the IC and the MC is 2,700 m (8855 ft)

1.7.4 Fiber-Optic Backbone

Fiber optics are an extremely effective means of moving backbone traffic Fiber optic cable is capable of carrying more data at higher speeds over greater distances than copper Optical fibers are also impervious to electrical noise and radio frequency interference Fiber also does not conduct electrical currents that can cause ground loops,

it transmits pulses of light Fiber optic systems also have high bandwidth and can work at high speeds This means that a fiber optic backbone with certain characteristics that is installed today may be upgraded in the future to even greater performance, when the terminal equipment is developed and becomes available This can make fiber optic very cost effective

Fiber has an additional advantage when used as a backbone media It can go much farther than copper Multimode optical fiber used as a backbone can support lengths of up to 2000 meters Single mode fiber optic cables can go up to 3000 meters Although optical fiber,

especially single mode fiber, can carry signals much farther than this (60 – 70 miles is feasible, depending on terminal equipment), these longer distances are considered to be out of the scope of the LAN standards.d

1.7.2 Horizontal cross-connect (HC)

The horizontal cross-connect (HC) is located in the TR closest to the work areas The HC, like all copper cross-connects, is typically a patch panel or punch down block and possibly networking devices such as hubs or switches It can be a rack mounted in a room or in a cabinet Since a typical horizontal cable system includes multiple cable runs to each workstation, it usually represents the largest concentration of cable in the building infrastructure A building with

a 1000 workstation LAN can typically contain a horizontal cable system consisting of 2000 to 3000 individual cable runs

Horizontal cabling includes the networking media, copper or optical fiber, that is used in the area that extends from the wiring closet to a workstation (See Figure 1) Horizontal cabling includes the

networking medium that runs along a horizontal pathway to the telecommunications outlet or connector in the work area and the patch cords or jumpers in the HC

Any cabling installed between the MC and another TR is known as backbone cabling The difference between horizontal and backbone cabling is clearly defined in the standards

Lab 2: Terminating A Cat5e Cable at a Cat5e Patch Panel

1.7.5 MUTOAs and Consolidation Points

Figure 1 Typical MUTOA Installation

Figure 2 Typical Consolidation Point Installation

Consolidation Points (CPs) and Multi-user Telecommunications Outlet Assemblies (MUTOAs) are provided in the TIA 568 B.1 standard to accommodate open office areas An open office area is a modular furniture (cubicles) arrangement These are often subject to frequently being rearranged Rather than replacing the entire horizontal cabling system feeding these areas, a CP or MUTOA can

be located close to the open office area and eliminate the need to replace the cabling all the way back to the TR whenever the furniture

is rearranged The cabling only needs to be replaced between the new work area outlets and the CP or MUTOA The longer distance of cabling back to the TR remains permanent

A MUTOA is a device that allows users to move, add devices, and make changes in modular furniture settings without re-running the cable Patch cords can be routed directly from a MUTOA to work area equipment (See Figure 1) A MUTOA location must be accessible and permanent, and may not be mounted in ceiling spaces

or under access flooring Similarly, it cannot be mounted in furniture unless that furniture is permanently secured to the building structure When using MUTOAs, the TIA/EIA-568-B.1 standard specifies the following:

■ At least one MUTOA is needed for each furniture cluster

■ Maximum 12 work areas can be used for each MUTOA

■ Patch cords at work areas shall be labeled on both ends with unique identifiers

■ Maximum patch cord length is 22 m (72.2 ft)

Consolidation points (CP) provide limited area connection access Typically a permanent flush wall-mounted, ceiling-mounted, or

fixtures, equipment, or heavy furniture Consolidation points differ from MUTOAs in that workstations and other work area equipment

do not plug into the CP like they do with the MUTOA (See Figure 2) Workstations plug into an outlet which is then hard wired to the CP The TIA/EIA-569 standard specifies the following:

■ At least one CP for each furniture cluster

■ Maximum 12 work areas for each CP

■ Maximum patch cord length is 5 m (16.4 ft) For both consolidation points and MUTOAs, TIA/EIA 568-B.1 recommends a seperation of at least 15 m (49 ft.)equipment between the TR and the CP or MUTOa This is to avoid problems dealing with crosstalk and return loss

2 Structured Cabling Standards and Codes

Standards are sets of rules or procedures that are either widely used,

or officially specified, and that serve as the gauge or model of excellence Standards can take many forms They can be specified by

a single vendor or be industry standards that support multi-vendor interoperability:

■ Standardized media and layout descriptions for both backbone and horizontal cabling

■ Standard connection interfaces for the physical connection of equipment

■ Consistent and uniform design that follows a system plan and basic design principles

Numerous companies, organizations, and even government bodies regulate and specify the cables in use In addition to these

organizations, local, state, county, and national government agencies issue codes, specifications, and requirements

The power of standards is this The network that is built to standards should work well, or interoperate, with other standard network devices The long term performance and investment value of many network cabling systems has been severely diminished by installers not knowing or following mandatory and voluntary standards

It is important to understand that these standards are constantly being reviewed and periodically updated to reflect new technologies and the ever-increasing requirements of voice and data networks Just as new technologies are added to the standards, others are dropped or phased out In many cases a network may include technologies that are no longer a part of the current standard or being eliminated Typically, this does not require an immediate changeover, but these older, slower technologies are eventually replaced in favor of faster ones Standards are often developed by or at the direction of international organizations that try to reach some form of universal standard Organizations such as TIA, IEEE, ISO, and IEC are all examples of international standards bodies These international standards organizations are composed of members from many nations, each of which has their own standards making process

In many countries, the national codes become the model for state/provincial agencies as well as municipalities and other governmental units to incorporate into their laws and ordinances The enforcement then moves to the most local authority Always check

codes for the most part take precedence over national codes, which take precedence over international codes

2.1 Telecommunications Industry Association (TIA) and Electronic Industries Association (EIA)

Figure 1 TIA/EIA Standards for buildings

Figure 2 TIA/EIA Structured Cabling Standards

The Telecommunications Industry Association (TIA) and Electronic Industries Alliance (EIA) are trade associations that jointly develop and publish a series of standards covering areas of structured voice and data wiring for LANs (See Figure 1)

Both TIA and EIA are accredited by the American National Standards Institute (ANSI, section 6.2.7) to develop voluntary industry standards for a wide variety of telecommunications products This means that many standards are often labeled ANSI/TIA/EIA The various committees and subcommittees of TIA/EIA develop standards for fiber-optics, user premises equipment, network equipment, wireless communications, and satellite communications

recommended topology and distance limits, media and connecting hardware performance specifications, and connector and pin assignments

TIA/EIA-568-B is the currently recognized Cabling Standard This standard is an updated version of the 568-A standard that specifies the component and transmission requirements for telecommunications media The TIA/EIA 568-B standard is divided into three separate sections: 568-B.1, 568-B.2, and 568-B.3

TIA/EIA-568-B.1 specifies the general requirements for a generic telecommunications cabling system for commercial buildings that will support a multi-product, multi-vendor environment TIA/EIA-568-B.1.1 is an addendum that applies to 4-pair unshielded twisted-pair (UTP) and 4-pair screened twisted-pair (ScTP) patch cables bend radius

TIA/EIA-568-B.2 specifies cabling components, transmission, system models, and the measurement procedures needed for verification of twisted pair cabling TIA/EIA 568-B.2.1 is an addendum that requirements for Category 6 cabling

TIA/EIA-568-B.3 specifies the component and transmission requirements for an optical fiber cabling system

TIA/EIA 569-A is the Commercial Building Standard for Telecommunications Pathways and Spaces The standard specifies design and construction practices within and between buildings that are in support of telecommunications media and equipment

TIA/EIA-606A is the Administration Standard for the Telecommunications Infrastructure of Commercial Buildings including cable labeling standards The standard specifies that each hardware termination unit have some kind of unique identifier This standard also outlines the requirements for record keeping and

TIA/EIA-607A is the standard for Commercial Building Grounding and Bonding Requirements for Telecommunications supports a multi-vendor, multi-product environment, as well as the grounding

practices for various systems that may be installed on customer premises The standard specifies the exact interface points between the building grounding systems and the telecommunications equipment grounding configuration and specifies building grounding configurations needed to support this equipment

electrotechnical standards for most of Europe CENELEC works with 35,000 technical experts from 19 European countries to publish standards for the European market It has been officially recognized

as the European standards organization by the European Commission

in Directive 83/189/EEC Many CENELEC cabling standards mirror ISO cabling standards with minor changes

Although CENELEC and the International Electrotechnical Commission (IEC) operate at two different levels, their actions have a strong mutual impact since they are the most important

standardization bodies in the electrotechnical field in Europe

Cooperation between CENELEC and the IEC is described in what is known as "the Dresden Agreement" since it was approved and signed

by both partners in that German city in 1996 This agreement was intended to expedite the publication and common adoption of International standards, and accelerate the standards preparation process in response to market demands This agreement was also intended to ensure rational use of available resources, and, therefore, full technical consideration of the content of the standard should preferably take place at international level

Web Link:

www.cenelec.org

2.3 International Organization for Standardization (ISO)

International Organization for Standardization (ISO) is an international organization composed of national standards bodies from over 140 countries American National Standards Institute (ANSI), for example, is a member of ISO ISO is a non-governmental organization established to promote the development of

standardization and related activities ISO's work results in international agreements, which are published as International Standards

ISO has defined a number of important computer standards, the most significant of which is perhaps the Open Systems Interconnection (OSI) model, a standardized architecture for designing networks

Web Link:

http://www.iso.org/iso/en/ISOOnline.frontpage

2.4 U.S Codes

For some networking projects, a permit is required to ensure that the work is being done properly Contact local zoning departments for information on permit requirements

To obtain copies of local or state building codes, contact the building official for the local jurisdiction All of the basic building codes, CABO, ICBO, BOCA, SBCCI, ICC, and so on, that are adopted throughout the United States can be purchased from the International Conference of Building Officials (ICBO)

Note: The Americans with Disabilities Act (ADA) has lead to several important changes in new construction, alterations, and renovations regarding networking and telecommunications Depending on the use of the facility, these changes may not be optional, and fines can be assessed for failure to comply

It is common for codes requiring local inspection and enforcement to

be incorporated into state or provincial governments and then possibly down to city and county enforcement units Building codes, fire codes, and electrical codes are examples Like occupational safety, these were originally local issues, but disparity of standards and often lack of enforcement has led to national standards These standards, when adopted by state or local authorities and enforced to appropriate levels are then turned over to the lower level authorities for implementation

Note that violating these codes can often be very expensive both in penalties and delayed project costs

Some codes may be enforced variously by city, county, or state agencies This means that a project within the city would be handled

by the appropriate city agencies, while those outside the city would

be covered by county agencies For instance, fire codes can be enforced by county building permit departments in some communities but by local fire department in others

While local entities inspect and enforce the codes, they do not often write them Standards making organizations frequently do that for them The National Electrical Code, for instance is written to sound like a legal ordinance This makes it possible for local governments to adopt the code by vote This may not happen regularly, and the government may fall behind Always know which version of the NEC

is in force for your area

Note that most countries have similar systems of codes Knowledge

of these local codes is important if you are planning to do a project that crosses national boundaries

2.5 Evolution of Standards

Figure 1 Changes to Horizontal Cabling Standards

As network bandwidth has increased from 10 Mbps to 1000 Mbps and beyond, it has created new demands on cabling Older types of cable are often inadequate for use in the faster modern networks For this reason, the types of cabling used changes over time, and the standards reflect this The following are the standards for TIA/EIA 568-B.2:

For twisted-pair cables, only 100-ohm Category 3, 5e, and 6 cables are recognized Category 5 cable is no longer recommended for new installations, and has been moved from the body of the standard into

an appendix Category 5e or greater is now the recommended cable for 100-ohm twisted pair

The Category 6 standard specifies performance parameters that will assure that product meeting the standard will be component

compliant, backwards compatible, and interoperable between vendors

When terminating Category 5e and higher cables, the pairs shall not

be untwisted more than 13 mm (0.5 in) from the point of termination The minimum bend radius for UTP horizontal cabling remains four times the cable diameter The minimum bend radius for UTP patch cable is now equal to the cable diameter since it contains stranded wires and so is more flexible than solid core copper cables used in horizontal cabling

The acceptable length of patch cords in the telecommunications room has changed from 6 m to 5 m (19.7 to 16.4 ft) maximum The

area jumper can be increased in length if the horizontal length is decreased a corresponding amount to keep total link segment length not longer than 100 m (328.1 ft) (See Figure 1) The use of a MUTOA or Consolidation Point also mandates a separation of at least

15 meters (49 ft) between the TR and the MUTOA or Consolidation Point, in order to limit problems with crosstalk and return loss All patch cords and cross-connect jumpers formerly were required to use stranded cable to provide the flexibility needed to survive repeated connection and reconnection The wording around this topic has now been changed from "shall" to "should" regarding stranded conductors This allows solid conductor cord designs

Patch cords are critical elements in the network system Language regarding the on-site manufacture of patch cords and jumpers still allows these cables to be created, but it is now strongly encouraged that network designers purchase cables that are pre-made and tested Category 6 and the emerging Category 7 are the newest copper cables available As category 6 cable is used more frequently, it is important for cable installers to understand its benefits

The significant difference between Category 5e and Category 6 is the means used to maintain the spacing between the pairs inside the cables Some Category 6 cables use a physical divider down the center of the cable Others have a unique sheath that locks the pairs into position Still other Category 6 cables use a foil screen that overwraps the pairs in the cable The latter type of cable is often called Screened Twisted Pair, or ScTP

To achieve even greater performance than Category 6, proposed Category 7 cables that are available use a fully-shielded construction which limits crosstalk between all pairs Each pair is enveloped within a foil wrap and an overall braided sheath surrounds the four foil-wrapped pairs A drain wire may be provided in future cables to facilitate grounding

Standards for the structured cabling will continue to evolve The focus will be on supporting the new technologies that are converging

on the data network Examples include:

■ IP telephony and Wireless utilizing a power signal in the transmission to provide power to the IP Phones or Access Points

■ Storage Area Networking utilizing 10GB Ethernet transmission

■ Metro Ethernet “last mile” solutions that require optimizing bandwidth and distance requirements

The standard for Power over Ethernet (PoE) (TIA/EIA #?) is developing and will be available in the near future PoE embeds a power signal over on the two extra pairs of 10/100 Fast Ethernet transmissions The power signal is used to allow IP phones to act like traditional analog phones by not requiring a power outlet near the

phone or wireless access point This helps enable deployment of these emerging technologies through significantly reducing the associated deployment costs

employment has nearly doubled from 56 million workers at 3.5 million worksites to 105 million workers at nearly 6.9 million sites

It is OSHA's responsibility to protect workers by enforcing U.S labor laws Technically speaking, OSHA is not a building code or building permit related agency However, OSHA inspectors have the power to impose heavy fines and to shut down a jobsite should they find serious safety violations Anyone who works on, or is responsible for,

a construction site or business facility needs to be familiar with OSHA regulations The organization offers safety information, statistics, and publications on its website

Web Link:

http://www.osha.gov

3.1.2 Underwriters Laboratories Inc (UL)

Underwriters Laboratories Inc (UL) is an independent, nonprofit product safety testing and certification organization UL has tested products for public safety for more than a century The UL focuses on safety standards, but has expanded its certification program to

evaluate twisted-pair LAN cables for performance according to IBM and TIA/EIA (Telecommunications Industry Association/Electronic Industries Alliance) performance specifications, as well as National Electrical Code (NEC) safety specifications The UL also established

a program to mark shielded and unshielded twisted-pair LAN cables, which should simplify the complex task of making sure that the materials used in the installation are up to specification Listing by

UL denotes initial testing and periodic retesting to assure continuing conformance to standards

UL tests and evaluates samples of cable, and then, after granting a UL listing, the organization conducts follow-up tests and inspections This independent testing and follow-through make the UL markings valuable symbols to buyers

The UL LAN Certification Program addresses not only safety, but also performance Companies whose cables earn these UL markings display them on the outer jacket (Level I, LVL I, or LEV I, for example)

Web Link:

http://www.ul.com

3.1.3 National Electrical Code (NEC)

The purpose of the National Electrical Code (NEC) is the practical safeguarding of persons and property from hazards arising from the use of electricity This code is sponsored by the National Fire Protection Association (NFPA) under the auspices of the American National Standards Institute (ANSI) The code is revised every three years

Several organizations, including UL, have established standards for flame and smoke that apply to network cables laid inside buildings However, the NEC contains the standards most widely supported by local licensing and inspection officials

3.1.4 NEC Type Codes

Figure 1 NEC Cable Type Codes

NEC type codes are listed in catalogs of cables and supplies These codes classify specific categories of products for specific uses, as shown in Figure 1

Generally, interior network cables are listed in the category of type

CM for communications or type MP for multipurpose Some companies choose to run their cables through the testing process as remote-control or power-limited circuit cables CL2 or CL3 (class 2 or class 3) general tests instead of through the CM or CP tests, but the flame and smoke criteria are generally the same for all tests The differences between these markings concern the amount of electrical power that could run through the cable in the worst case MP cable is subjected to tests that assume the most power-handling capability, with CM, CL3, and CL2 going through tests with decreasing levels of power handling

Web Link:

http://www.nfpa.org/Home/index.asp http://www.osha.gov/

3.2 Safety Around Electricity

In addition to learning about the industry's safety organizations, the cable installer should learn about basic safety principles that will be used every day on the job and that are also necessary for the

curriculum labs Since there are many hazards when installing cable, the installer should be prepared for all situations, so that accidents or injuries can be prevented

3.2.1 High-voltage

Cable installers work with wiring designed for low-voltage systems The voltage applied to a data cable would be hardly noticeable to most people However, the voltage of network devices that data cables plug into can range from 100 to 240 volts (in North America)

If a circuit failure allowed the voltage to become accessible, it could give the installer a dangerous shock and it could be fatal In addition,

it is not unknown for a low voltage installer to inadvertently skin the insulation off of existing high voltage wiring and contact voltage that way

Do not become complacent to the hazards of high-voltage wiring nearby just because most of the work is dealing with low-voltage If someone suddenly comes in contact with high-voltage, they may find

it difficult to control their muscles or have the ability to pull away

3.2.2 Lightning and high-voltage danger

High-voltage is not limited to power lines Lightning is another source of high-voltage Since lightning can be fatal as well as damage network equipment, care must be taken to prevent it from entering the network cabling

The following precautions should be taken to avoid personal injury and damage to network equipment from lightning and electrical shorts:

All outside wiring must be equipped with properly grounded and registered signal circuit protectors at the point where they enter the building, known as the entrance point These protectors must be installed in compliance with local telephone company requirements and applicable codes Telephone wire pairs should not be used without authorization If authorization is obtained, do not remove or modify telephone circuit protectors or grounding wires

Never run wiring between structures without proper protection In fact, protection from lighting effects is probably one of the biggest advantages to using fiber-optics between buildings

Avoid wiring in or near damp locations

Never install or connect copper wiring during electrical storms Improperly protected copper wiring can carry a fatal lightning surge for many miles

3.2.3 High-voltage safety test

Voltage is invisible Its effects are seen in tools that run, equipment that operates, or the unpleasant experience of getting shocked

When working with anything that plugs into the wall for power, it is a safety best practice to check for voltages on surfaces and devices before coming in contact with them Using a known reliable voltage measurement device such as a multimeter or voltage detector, take measurements immediately before starting work Measure again whenever work is resumed the following day or after a break on any job, because someone may have made changes Recheck the

measurements again when finished

Some forms of electricity cannot be predicted Lightning and static electricity fall into this category Never install or connect copper wiring during electrical storms Copper wiring can carry a fatal lightning surge for many miles This is particularly an issue with external wiring that is strung between buildings or underground wiring Equip all outside wiring with properly grounded and approved signal circuit protectors These protectors must be installed

in compliance with the local codes, which in most cases will align to national codes

3.2.4 Grounding

Grounding works by providing a direct path to the earth for any voltages that come in contact with it Equipment designers purposely

isolate the circuits in equipment from the chassis, that is, the box the

circuits are mounted in Any voltage that leaks from the equipment to its chassis should not stay in the chassis Grounding equipment conducts any stray voltage to the earth without hurting that equipment Without a proper path to ground, stray voltages may use another path to the ground, such as a person's body

The grounding electrode is the metal rod that is buried in the ground near the entrance point of the building, that is, the place where electricity enters a building How the ground system connects to the earth is often another matter For years, cold water pipes, which enter the building from the underground water mains, were considered good grounds Large structural members, such as I-beams and girders, were also acceptable Although these may provide an adequate path to ground, most local codes now require a dedicated grounding system, such as installed grounding conductors connecting equipment to grounding electrodes

Be aware of the grounding system in the lab and on each job site It should be verified that the grounding system actually works It is not uncommon to find that grounding was improperly done or was never

installed in the first place A more common situation occurs when an installer takes a few shortcuts and accomplishes a technically

adequate ground, but in a non-standard way Later, changes to other parts of the network or to the building itself may destroy or eliminate the non-standard ground system, leaving equipment and people at risk

3.2.5 Bonding

Figure 1 Bonding

Bonding involves providing a means for various wiring fixtures to interconnect with the grounding system (See Figure 1) It may be thought of as an extension of ground wiring A device like a switch or router may have a bonding strap between its case and a ground circuit

to ensure a good connection

Properly installed bonding and grounding will:

■ Minimize electrical surge (spike) effects

■ Maintain the integrity of the electrical grounding plant

■ Provide a safer and more effective path to ground Telecommunications bonds are typically used in the following:

■ Entrance facilities

■ Equipment rooms

■ Telecommunications rooms

3.2.6 Grounding and bonding standards

TIA/EIA on Grounding and Bonding

Industry Association/ Electronics Industry Alliance-607A 607A) standard It supports a multi-vendor, multi-product

(TIA/EIA-environment, as well as the grounding practices for various systems that may be installed on customer premises TIA/EIA-607A specifies the exact interface points between a building's grounding system and the telecommunication equipment grounding configuration It also specifies that the building's grounding configurations needed to support this equipment

Web Link:

http://www.nfpa.org/

http://www.tiaonline.org/

3.3 Lab and Workplace Safety Practices

Although cable installation is generally a safe profession, there are plenty of opportunities for being injured Many injuries are caused when installers come in contact with stray sources of voltage, called foreign voltages, such as lightning, static electricity, or other types of voltages caused by installation faults or induction currents that somehow find themselves onto network cables

Whenever working in walls, ceilings, or attics, the first thing that should be done is to turn off power to all circuits that might pass through those work areas If it is not clear which wires pass through the section of the building being worked in, a good rule to follow is to shut off all power Never touch power cables Even if all power to the area has been shut off, there is no way to know if circuits are still

"live"

Most countries have one or more agencies that develop and administer safety standards Some of these are designed to ensure public safety while others are designed to protect the worker Those that protect the worker usually cover laboratory safety, general workplace safety, compliance with environmental regulations, and hazardous waste disposal

3.3.1 Workplace safety

The following are guidelines for keeping a workplace safe:

Before beginning work, learn the locations of all fire extinguishers in the area A small extinguishable fire can get out of control if no one is able to locate an extinguisher quickly

Always find out in advance what the local codes are Some building codes may prohibit drilling or cutting holes in certain areas such as firewalls or ceilings The site administrator or facility engineer will be able to help determine which areas are off limits

When installing cable between floors, use a riser rated cable Riser cable is covered with a flame retardant fluorinated ethylene propylene (FEP) jacket, and therefore will not allow flames from one floor to use the cable to reach another floor

Outdoor cables typically have a polyethylene jacket (PVC)

Polyethylene burns readily and gives off dangerous gases NEC codes state that polyethylene building entrance cables cannot be exposed more than 15 m into a building If greater distances are required, the cable must be in metallic conduits

Consult the building's maintenance engineer to find out if there is asbestos, lead, or PCB in the working areas If so, follow all government regulations in dealing with that material These materials are called hazardous for a reason No one’s health should be risked

by working unprotected in these areas

Finally, if cable must be routed through spaces where air is circulated,

be sure to use a fire-rated cable (plenum rated) The most common plenum cables are jacketed with Teflon or Halar Plenum grade cable does not give off poisonous gases when it burns like regular cables which have a polyvinyl chloride (PVC) jacket

3.3.2 Ladder Safety

Ladders come in many sizes and shapes to be used for many specific purposes They can be made of wood, aluminum, or fiberglass and designed for either light or industrial use The two types that are most common are straight ladders and stepladders Regardless of the type

or construction, be sure the ladder has a label certifying that it complies with specifications of the American National Standards Institute (ANSI) and that Underwriters Laboratories (UL) lists it as passing its standards

Select the right ladder for the job Be sure that the ladder is long enough to work from comfortably and sturdy enough to withstand repeated use Fiberglass ladders are most commonly used in cable installation Although aluminum ladders are lighter, they are less stable and should never be used around electricity When working near electricity, only fiberglass ladders should be used

Inspect the ladder first Any ladder can develop a problem, which can render it unsafe Inspect ladders for loose or damaged rungs, steps, rails or braces Make certain the spreaders on stepladders can be locked in place and that the ladder has safety feet which will provide more stability and reduce the chances of the ladder slipping while working Never use a ladder that is defective

Stepladders should be fully opened with the hinges locked Straight ladders should be placed at a four-to-one ratio This means the base of the ladder should be 0.25 m (10 in.) away from the wall or other