STRUCTURED CABLING SYSTEM

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NETWORK CABLING STANDARDS OVERVIEW

NETWORK CABLE SOLUTIONSMODULE 1-A

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NETWORK CABLING STANDARDS

Why?

• Provide personal safety• Protect equipment from failure• Recognize regulatory considerations• Meet performance requirements

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• Presentation Topics– Historical perspective of LAN cabling– Current standards for structured systems cabling– The TIA Standards– The ISO Standards– The CENELEC Standards– Standards Comparison

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• Historical Overview– Throughout 1980’s, various network cabling and

connector techniques were used. For example:• IEEE 802.3 Trunk and AUI transceiver cables (bus

topology)• IEEE 802.5 Token Ring (ring topology)• Proprietary broadband and baseband over twisted

pair and coax

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NETWORK CABLING STANDARDS• 1990’s marked the introduction of structured

cabling system standards for data communications.– 1990 release of EIA/TIA-568 (North American)– 1991 - 2007 various addenda (TSBs)– 1994 ISO/IEC 11801 (International)– 1995 revision of 568 to TIA/EIA-568-A– 1995 EN 50173 (CENELEC)– 2002 ISO/IEC 11801 (International) Edition 2.– 2005 revision of 568 to TIA/EIA-568-B inclusions of

various addenda (TSBs)

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• To date, several addenda had been released due to the bandwidth requirement. Cat7a is even in the process.

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These are some of the standards organizations that dominate the world market for design and implementation of structured cabling systems.

• Standard Organizations– TIA (Telecommunications Industry Association)– ISO (International Standard Organizations)– CENELEC (European Community for Electrotechnical

Standardization)– NEMA (National Electrical Manufacturers

Association)– ICEA (Insulated Cable Engineering Association)

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NETWORK CABLING STANDARDS• Reasons why Structured Cabling Standards were

developed– To create generic cable and connector designs– Establish standard cabling architecture – Establish minimum performance guidelines for cables,

connectors and system links– Develop cabling performance specifications that can be

used by systems designers and active component manufacturers

– Create a transparent physical media that will support all current and future network protocols and applications

– Reduce physical layer costs for LAN cabling components

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• North American Standards– TIA/EIA-568-A (Cabling components and Architecture)– EIA/TIA-569 (Cabling pathways and spaces)– TIA/EIA-606 (Cabling system administration)– TIA/EIA-607 (Grounding and bonding of cabling system)– Technical Systems Bulletin (TSB)

• TSB-67 (Horizontal link performance for UTP cabling)• TSB-72 (Optical fiber cabling guidelines for commercial building)• TSB-75 (Open office cabling guidelines, e.g., zone distribution)

• Referenced Standards (ICEA, ASTM, NEC, UL)

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ADDENDA TO 568-A AND FUTURE WORK

• TIA/EIA-568-A-1TIA/EIA-568-A-1 - Propagation Delay and Delay Skew• TIA/EIA-568-A-2TIA/EIA-568-A-2 - Corrections and Additions to TIA/EIA-568-A

(centralized optical fiber cabling, transposition, polarization, etc..)

• TIA/EIA-568-A-3TIA/EIA-568-A-3 - Bundled cables, must be 3dB better than the specified p-p NEXT loss for each cable type

• TIA/EIA-568-A-4TIA/EIA-568-A-4 - Production of Modular Cord NEXT Loss Test Method and Requirements for UTP Cabling

• TIA/EIA-568-A-5TIA/EIA-568-A-5 - Add’l Transmission Performance Spec for 4-Pair 100 Enhanced Cat 5e Cabling

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ADDENDA TO 568-A AND FUTURE WORK

• TIA/EIA TSB 95TIA/EIA TSB 95 - Additional Transmission Performance Guidelines for 4-Pair 100 Category 5e Cabling-ELFEXT

• PN-3139PN-3139 - Technical Specification for 100 STP Cabling • PROPOSED ‘568-B.1PROPOSED ‘568-B.1 - Commercial Building

Telecommunications Cabling Std: Part 1, Gen. Reqmt• PROPOSED ‘568-B.2PROPOSED ‘568-B.2 - Commercial Building

Telecommunications Cabling Std: Part 2, Twisted-Pair Media• PROPOSED ‘568-B.3PROPOSED ‘568-B.3 - Commercial Building

Telecommunications Cabling Std: Part 1, Optical Fiber Media

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FUTURE SPECIFICATIONS

• Category 7Category 7– describe a new performance range for fully STP cabling– will be specified in the frequency range of 1-600 MHz– backward compatibility

• Category 7aCategory 7a– describe a new performance range for fully STP cabling– will be specified in the frequency range of 1000-1200 MHz– backward compatibility

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ANSI/TIA/EIA-568-A“Commercial Building Telecommunications

Cabling Standards”

• This document was created and is regularly updated to provide the communications industry with a “standards-based” structured network cabling platform that will support a wide range of communications applications.

• Originally adopted in 1991 as EIA/TIA-568• 568-A approved in October 1995, replaces

568, TSB-36, TSB-40A

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ANSI/TIA/EIA-568-A

• Contents– Structured Cabling Topologies– Cable Distances, Installation & Grounding Guidelines– Cable Media– Work Area defined– Telecommunication Equipment Room and Entrance

Facility location, function and design.– 100 ohm UTP Cabling System– Optical Fiber Cabling System– Hybrid and Undercarpet Cables

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ANSI/TIA/EIA-568-A

• Scope– Supports wide range of different sites

• Geographical separation 3000 meters (9840’)• 1,000,000 square meters (10,000,000 sq.ft.)• Up 50,000 users

– Useful life span in excess 10 years – Applies to the communications wiring of buildings

that are office oriented.

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ANSI/TIA/EIA-568-A

• Recognized Cables-Horizontal & Backbone– 4 pair 100-ohm UTP– higher than 4 pair for backbone, e.g., 25-pair– 62.5/125 duplex optical fiber cable– Single-mode optical fiber in backbones– UTP cables with > 4 pairs for use in backbones– Hybrids acceptable. (TIA/EIA-568-A-3, Addendum)

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ANSI/TIA/EIA-568-A

• Topology-Horizontal– Star topology

• Work area outlets connected to telecommunications closets– Maximum cabling length 100 meters (328 ft.)

• Horizontal distance 90 metes• Work station jumper 3 meters• Cross connect jumpers & patch cords 7 meters

– Outlets must be Category compliant with horizontal cabling

– Patch cords must be Category compliant with horizontal cabling

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ANSI/TIA/EIA-568-A

• Recommended Horizontal Cabling– Minimum of two telecomm outlets shall be

provided for each work stations– Work stations shall be supported by at least one 4

pair 100-ohm UTP– The other/second outlet at work station shall be

supported by one or more of the following:• 4-pair 100-ohm UTP• 62.5/125 duplex optical fiber cable

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ANSI/TIA/EIA-568-A

• Physical star topology for structured cabling per TIA/EIA-568-A can support the logical connection methodologies of most networking architectures.

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ANSI/TIA/EIA-568-A

• Topology– Conventional hierarchical star topology.– Non-star configurations can be accommodated

with interconnections, electronics, or adapters. – If bus and ring configurations are anticipated,

direct connections between telco closets are allowed.

• Direct connections are in addition to star topology

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ANSI/TIA/EIA-568-AStructured cabling physical star topology

• No more than 3 X-connects between each horizontal cross-connects.

• Maximum of two hierarchical levels of X-connects

• Cabling can be UTP, FTP, STP & Fiber

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ANSI/TIA/EIA-568-A

• Installation– Splices are not allowed as part of the horizontal

cabling.– Each four pair cables shall be terminated on a

eight position jack. – Pin assignments shall be as per T568A or T568B.– Category 5e, pair untwisting not more than 0.5”.

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PIN ASSIGNMENTS

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ANSI/TIA/EIA-568-A

• Grounding– Ensure that grounding conforms to TIA/EIA 607,

NEC and local requirements.– Ensure that each telco closet, equipment room,

and entrance facility has grounding access.– Ensure grounding is available for cross-connects,

patch panel racks, telco and data equipment.

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TIA/EIA-TSB-67“Transmission Performance Specifications for Field

Testing of Unshielded Twisted Pair Cabling Systems”

• This document was developed to give the engineer and installer a means to evaluate UTP horizontal cabling performance for Category 3, 4 and 5e links (later applied to higher Category).

• This document is used as an addendum to TIA/EIA-568-A

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TIA/EIA TSB-67

• Contents – Channel and basic links defined for horizontal cabling– Test Parameters: NEXT, Attenuation, Wire Mapping,

Physical vs. Electrical Length– Defines data reporting and accuracy– Field measurement procedures– Annex A defines field test instruments

• Accuracy• Test Set-up• Reference Test Methods• Electrical Length Measurement Methods

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TIA/EIA TSB 67Schematic Presentation of a Basic Link Test Configuration

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TIA/EIA TSB 67Schematic Presentation of a Channel Link Test Configuration

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TIA/EIA TSB-72“Centralized Optical Fiber Cabling”

• Use of optical fiber for centralized cabling within a building.• This cabling option is in addition to the TIA/EIA-568-A

topology and distance guidelines for structured cabling using optical fiber.

• Allows for workstation cable runs originating in the equipment room.

• Allows for non-distributed, centralized network electronics.

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TIA/EIA TSB-72

• Allows for future cabling modifications including addition of telecommunication closets without need for re-cabling.

• Follows TIA/EIA-568-A fiber cabling specifications• Maximum cabling distance - Backbone & horizontal is 300

meters (90 meters maximum for horizontal portion)

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TSB-75 Additional Horizontal Cabling Practices for Open Offices

32Application of Multi-user Telecommunications Outlet

Assembly

ANSI/EIA/TIA-569“Commercial Building Standard for

Telecommunications Pathways and Spaces”

• Created as a guideline for architects, engineers and construction industry to provide a building and campus cabling infrastructure that will remain useful and exhibit no or few problems for many years.

• Developed by participants from - America Institute of Architects and Construction Specification Institute

• Follows good building design guidelines set forth by– BICSI (Building Industry Consulting Services

International)– BOMA (Building Owners and Managers Association)– IBI (Intelligent Building Institute)– IFMA (International Facility Management Association)

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ANSI/EIA/TIA-569

• Contents – Horizontal Pathways (Under-floor, Access Floor,

Conduit, Trays, Ceiling, Perimeter, etc.)– Backbone Pathways (Inter and Intra-building)– Workstation Pathways and Telecom Outlets– Telecommunications Closet Design– Equipment Room Design– Entrance Facilities– Fire Stopping and Grounding– Pathway Separation from EM Energy Sources

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ANSI/EIA/TIA-569

• Conduit Types Recognized:– Electrical metallic tubing– Rigid metal conduit– Rigid PVC

• Conduit Type Not Recommended:– Metal flex conduit

• Cable suffers from abrasion 35

ANSI/EIA/TIA-569• Installation Guidelines

– Maximum run lengths without pull point = 30 meters (100 feet).

– Maximum of two 90 degrees bends between pull boxes or pull points.

– Fish tape or pull cord shall be placed in installed conduit.

– Inside Radius of a bend:• Less than 50mm (2 in.) - 6 times the internal diameter• Greater than 50mm (2 in.) - 10 times the internal diameter• Conduit to be used for fiber optic cable - 10 times the

internal diameter.

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ANSI/EIA/TIA-569

• Installation Guidelines– Single conduit run extending from a

telecommunications closet shall not serve more than three outlets

– Conduit shall be reamed to prevent cable jacket abrasion.

– Conduit shall be terminated with an insulated bushing.

– Minimum conduit size based on percent fill

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ANSI/EIA/TIA-569 : Conduit Size Recommendation

ANSI/EIA/TIA-569

• Recommended maximum percent Conduit Fill for Backbone Cable– One cable 53% fill– Two cables 31% fill– Three cables 40% fill

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ANSI/EIA/TIA-569

• Pathway Separation– Closed metal pathways provide adequate

protection from capacitively coupled (rapid changes in high voltage) in commercial buildings.

– Closed metal pathways of ferrous induction suppression material shall be used in areas of high inductively coupled noise (rapid changes in high current)

– Open or non-pathways shall be placed with sufficient separation.

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ANSI/EIA/TIA-569-1990

Separation of Telco Path From </= 480V PowerCondition Minimum Separation Distance

< 2 kva 2-5 kva > 5kva

Unshielded powerlines near open ornon metal pathways 5 in. 12 in. 24 in.

Unshielded powerlines near groundedmetal path. 2.5 in. 6 in. 12 in.

Power lines ingrounded metalconduit neargrounded metalconduit path. -- 3 in. 6 in.

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ANSI/EIA/TIA-606“Administration Standard for the

Telecommunications Infrastructure of CommercialBuildings”

• Developed as to establish standardized cabling administration procedures for labeling and documentation

• Designed for use with TIA/EIA-568-A and EIA/TIA-569

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ANSI/EIA/TIA-606

• Contents:– Administration Concepts

• Identifies, Records, Linkages– Pathways and Space Administration

• Identifiers, Labeling, Records, Reports– Wiring System, Administration

• Identifiers, Label, Records, Reports, Drawings– Grounding and Bonding Administration– Labeling and Color Coding:

• Labels and Termination Fields

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ANSI/EIA/TIA-606

• Scope– To provide a uniform administration scheme that

is dependent of applications which may change several times throughout the life of the building.

– Ties into TIA/EIA 568-A and EIA/TIA-569

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ANSI/EIA/TIA-606

• Areas of infrastructure to be administered– Termination for the cable located in work areas,

telecommunication closets, equipment rooms and entrance facilities

– Cable between the terminations– Pathways between terminations that contain the

media– Spaces where terminations are located– Bonding/grounding as it applies to

telecommunications

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ANSI/EIA/TIA-606• Cable Record

– Cable identification number• Fiber optic backbone…FB01• Copper backbone…CB01• Copper 4 pair, plenum…C5P0001

– Description of cable• 4 pr., Cat. 5e• 6 fiber, 62.5, OFNR

– Unterminated/ Damaged / Available• References to specific conductors and their availability

Note: Identifier formats are listed in detail within the TIA/EIA-606 standard.

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ANSI/EIA/TIA-606

• Cable Record– Required linkages

• Alpha numeric identification specific to each termination

– End 1…TC3A-B17-A1– Telco closet 3A, termination hardware B17, termination on

position A1

– Pathway records• Cable tray…CT01• Conduit…CD02• Backbone conduit…BCD08

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ANSI/TIA/EIA-606

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Cable Record

Required Information Data Comments

Cable ID FB01 6 fiber, 62.5, OFNR 422006Unterm 0Damaged 0Available 2 #5 Slate, #5 White

ANSI/TIA/EIA-606

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Cable Record

Required Linkages End 1 End 2 Comments

Term Pos. Record#1 Blue TC3A-B17-A1 ER101-01-A1#2 Orange TC3A-B17-A2 ER101-01A2#3 Green TC3A-B17-A3 ER101-01A3#4 Brown TC3A-B17-A4 ER101-01A4#5 Slate TC3A-B17-A5 ER101-01A5 Available#6 White TC3A-B17-A6 ER101-01A6 Available

Splice Records M1H01-S010 1500 ft from TC3APathway Records CD015-CD016 Path 2 conduits at MH-101Grounding Records N/A

ANSI/TIA/EIA-607“Commercial Building Grounding and Bonding

Requirements for Telecommunications”

• Created to provide standard methodologies for grounding of building and communication infrastructures for the safe and reliable operation of electrical and electronics systems.

• This document is to be used in conjunction with– ANSI/TIA/EIA-568-A-1995– ANSI/TIA/EIA-569-1990– ANSI/TIA/EIA-606-1993– TIA/EIA TSB-60 (Backbone for Residential and Light

Commercial Buildings)– ANSI/TIA/EIA-570-1991 (residential communications

wiring)

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ANSI/TIA/EIA-626“Multi-mode Fiber-Optic Link Transmission Design”

• This standard has been created to provide a common procedure for design a multi-mode digital fiber optic link

• Cable types and other passive and active equipment are defined in detail.

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ANSI/TIA/EIA-626

• Contents– Related TIA documents– Cable Optical Fiber– Passive Optical Devices: Connectors, Splices, etc.– Fiber Optic Transmitter/Source Choices– Fiber Optic Receiver/Detector Choices– Link Definition– Bandwidth Budget– Loss Budget

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NEMAStandards Publications No. WC 63-1994

“Performance Standard for Premise Telecommunications Cables”

• Specifically for cables (no structured cabling architecture or topology guidelines)

• Original specification for high performance UTP cabling

• Significant role in defining cable performance specifications for electronic and electric applications

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INTERNATIONAL STANDARDS FORSTRUCTURED CABLING

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ISO/IEC 11801“Information Technology - Generics Cabling

for Customer Premises”

• This document was created and is regularly updated to provide the communications industry with a “standards-based” structured network cabling platform that will support a wide range of communications applications.

• Closely parallels the TIA/EIA-568-A Document• Minor performance differences for cables and

links.

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ISO/IEC 11801

• Variation of recommendations Vs. TIA/EIA-568-A– Return Loss is reported as real impedance– Link performance is defined as “Class”.

• ISO Class D link is equivalent to TIA/EIA Cat 5e link• Minimum performance for class D links are slightly less

than Category 5e links.– Multimode fiber (62.5/125):

11801 TIA/EIA-568-A 200 MHz-Km @ 850nm 160 MHz-Km @ 850nm

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EC Standards for StructuredCabling - CENELEC

• European Standard EN 50173– “Information Technology - Generic Cabling

Systems”

• European Standard EN 50167 – “Sectional Specification for Horizontal Floor wiring

cables with common overall screen for use in digital communication”

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EC Standards for StructuredCabling - CENELEC

• European Standard EN 50168 – “Sectional Specification for Work Area Wiring Cables with

common overall screen for use in digital communications”• European Standard EN 50167

– “Sectional Specification for Backbone Cables, riser and campus, with common overall screen for use in digital communication”

• These documents have been drafted directly from the ISO/IEC 11801 standard

• They are intended to address various nuances within the European Community.

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STANDARDS CROSS REFERENCE

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STANDARDS CROSS REFERENCE

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FUTURE• TIA-568-B.3

– 62.5/125µm Multimode• OFL: 160 MHz•km @ 850nm• OFL: 500 MHz•km @ 1300nm

– 50/125 µm MMF• OFL: 500 MHz•km @ 850nm• OFL: 500 MHz•km @ 1300nm

• TIA-568-B.3-1– 50/125 µm Laser Optimized MMF

• OFL: 1500 MHz•km @ 850nm• OFL: 500 MHz•km @ 1300nm• RML: 2000 MHz•km @ 850nm

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ISO/IEC 11801:2002 OM1 (62.5/125 µm)

OFL: 200 MHz•km @ 850nm OFL: 500 MHz•km @ 1300nm

OM2 (50/125 µm) OFL: 500 MHz•km @ 850nm OFL: 500 MHz•km @ 1300nm

OM3 (50/125 µm) OFL: 1500 MHz•km @ 850nm OFL: 500 MHz•km @ 1300nm RML: 2000 MHz•km @ 850nm

OFL – Overfilled Launch (LED Bandwidth)RML – Restricted Mode Launch (LASER Bandwidth)

FUTURE

• 40 GbE and 100 GbE fiber applications under development

• IEEE HSSG – 802.3ba• Current draft is 1.1

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Beyond 10 GbpsBeyond 10 Gbps

FUTURE

• 40 GbE – Server and computing needs

– Servers, high performance computing clusters, blade servers, SANs and network attached storage

• 100 GbE – Core networking applications

– Switching, routing, and aggregation in data centers, internet exchanges and service provider peering points, and high bandwidth applications, video on demand, and other high performance computing environments

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Why 2 application speeds?Why 2 application speeds?

FUTURE

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Server Market EvolutionServer Market Evolution

GENERAL CABLE INSTALLATION PRACTICES

NETWORK CABLE SOLUTIONSMODULE 2-A

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GENERAL CABLE INSTALLATION

• Scope:– To provide guidelines for the installation of high

performance cables under a variety of conditions.

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CABLE INSTALLATION

• Safety– Wear proper clothing

• Safety glasses• Hard hats• Proper footwear• Gloves

– Locate electrical wiring– Secure the area– Plan for safety

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• Considerations– Do not exceed the minimum bend radius.– Do not exceed the tensile loading.– Lock in all components of a cable in relation to

one another.– Use cable lube where necessary.– Inspect cable route for surfaces that may abrade

the cable.

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SMALL SINGLE CABLE

1. Twist the cable end around the cable for a length of 8-10 inches (20-25 cm)

2. Tape the twisted portion with electrical tape.3. Attach the pull string to loop

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MULTIPLE SMALL CABLE

1. Align ends of cables to be pulled.2. Using electrical tape, tape 8 to 10 inches (20

to 25 cm) of cable ends together.3. Divide the bundle of cables into 2 roughly

equal groups.4. Pass the pull string between these two

bundles. Knot the string forward of the tip.5. Tape the pull string at the end.

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MULTIPLE CABLES

1. Strip off outer jacket from cables exposing the conductors 8 to 10 inches (20 to 25 cm).

2. Separate the conductors within each cable into two equal bundles.3. Twist bundles from each cable together to form

two legs.4. Twist the two legs together forming a loop.5. Tape the end of the cable and the loop using electricians tape

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MULTI PAIR CABLE

1. Strip 10 to 12 inches (25 to 30 cm) of the outer jacket.

2. Split conductors and spacers or strength members into roughly two equal bundles.

3. Twist the two bundles to form a loop.4. Using electrical tape, tape part of the cable as

well as the loop.

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FIBER OPTIC CABLE

1. Strip off 14 to 16 inches (35 to 40 cm) of the outer jacket of the cable.

2. Bend the fibers back onto the cable and tape in place using electrical tape.

3. Twist the Kevlar to facilitate handling then bring back over the cable forming a loop.

4. Continue taping the fibers and the Kevlar past the end of the cable jacket.

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CONDUIT INSTALLATION• Three pulling situations

– Dip to dip– Straight pulling between manholes– Pulling around corners

• Two pulling methods– By hand.– By machines.

• Decision is based on several factors– How clear is the conduit– Bends to the conduit– Size and weight of the cable.

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CONDUIT INSTALLATION

• Minimizing Tensile Loads– Changes in cable direction have a greater effect

on cable loads than the length of the cable pull.• Use center pulling or back feeding methods with pulls

longer than 400 meters.• Minimize pulls through 90 degrees bends (maximum of

two bends).• Monitor cable tension during cable pulls when using

winches.

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PULL BOXES

• Minimizing Tensile Loads– Backfeeding reduces tension on the cable and

allows easy cable pulling through the use of pull boxes

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CABLE TRAYS

• Protect cable from sharp edges and abrasive surfaces.

• Mount Cable on the sides or the underside of tray.

• Observe the minimum bend radius at all turns.• Avoid excess weight on cable at cable tray

runs.• Fiber to be placed on top of copper.

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RISER INSTALLATION

• Secure cable at the top of the run. The use of a split mesh grip is recommended to ensure that the minimum bend radius is maintained and the cable is secured firmly.

• Cable ties are used to prevent unnecessary movement, not to support cable.

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RISER INSTALLATION

• Vertical Risers– Alternative method

• Mount steel messenger in riser anchoring at top and at bottom.• Attach cable to the messenger using traditional means.

• Drop down or pull up. – Usually you have a choice in whether to drop the cable

down the riser or to pull it up.– Best alternative is to lower the cable through the riser.

• Why? Because its easier!

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RISER INSTALLATION

• Riser Pull1. Set up the cable reel on a jack stand 30 feet (20 meters)

from the riser opening.2. Have as many people as can be spared on the reel, and

sufficient personnel on the lower floors to guide the cable.3. Slowly feed the cable off the top of the reel into the

opening. Even if the cable is heavy its own weight on the floor should act as a brake.

4. Continue to feed the cable slowly until the person on the floor below can guide the cable in the next opening.

5. Proceed until the cable has been lowered to the destination floor.

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RISER INSTALLATION

• If the cable is to be placed in an open riser.1. Set up a pulley over the middle of the riser.2. Loop the cable over the pulley.3. Proceed as described earlier.

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HORIZONTAL INSTALLATION• Floor or ceiling duct

– Follow the same procedures as for conduits.• Ceilings

– New construction with open ceilings typically does not present significant problems.

– Existing building with a ceiling in place requires the careful placement of a pull string.

– The typical installation an installer will face is a suspended ceiling.

– The following procedure is for an existing ceiling. It is very similar to procedures in new construction.

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HORIZONTAL INSTALLATION

• Ceilings1. Open the ceiling tiles as needed. Every other one is

usually more than sufficient. Careful, ceiling tiles are damaged easily.

2. Tie a 1/4” inch handline to a weight. Toss this weight above the ceiling from one opening to another. Start at the drop end and continue until you reach the closet.

3. Set boxes or reel of cables near the drop points in clusters.4. Mark the ends of the cable with the drop locations. Use a

Sharpie or Magic Marker pen.5. Attach bundle of cable to pull string and pull to next

cluster.

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HORIZONTAL INSTALLATION

• Ceilings 6. At second cluster repeat marking the cable and

attaching to pull string.7. Continue until all clusters are picked up then

continue the pull to the closet.8. Once cable has been brought to the closet return

to the work area, pull sufficient cable from the boxes or reels to reach the work box and fish through the walls using a snake.

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HORIZONTAL INSTALLATION• Ceilings Distribution to Large Open Areas

– Overall idea is to pull as many individual stations as is possible at the same time.

– The best way usually is to divide the area into thirds of quarters.

• Large Open Space Example– An area with 60 workstations can be divided into

three 20 stations clusters each having two cables.– One cluster may be the furthest away the second mid

distance and the third the closest.– We would make three pulls of 40 cables each from

the closet to a central area for each cluster.

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QUESTIONS?

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UTP PERFORMANCE PARAMETERS

NETWORK CABLE SOLUTIONSMODULE 2-B

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UTP PERFORMANCE ATTRIBUTES

• Factors Affecting UTP Cable Performance– Category– Attenuation– Capacitance– Noise– SRL– Impedance– Crosstalk / NEXT– SNR

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DeciBel (dB)

• Measurement of signal loss• Relation of voltage-in to voltage-out• dB scale is a nonlinear measurement• Attn=20*Log (voltage-in/voltage-out)

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CATEGORY• Category 1

– 1 Mbps; Alarm Systems, voice only (telephone wire), POTS• Category 2

– 4 Mbps; Digital voice, EIA-232, low-speed data• Category 3

– 10 Mbps; 10BaseT Ethernet, 4Mbps Token Ring, basic rate ISDN, Data up to 10 Mbps

• Category 4 – 16 Mbps; Token Ring, data up to 20 Mbps

• Category 5e– 100 Mbps; TP-PMD, SONet, OC-3 ATM, 100BaseTX, Data

up to 100 Mbps

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ATTENUATION

• Attenuation (dB/m)– As with fiber, attenuation is the degradation of

signal level along the cable length– Attenuation is caused by resistance occurring at

high frequencies.– Data Cable’s UTP Cat 5e cables typically

demonstrate worst case attenuation at distances up to 90m values 5% below the maximum specified values.

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ATTENUATION

• Attenuation– Reduction in amplitude (height) of a transmitted

signal.– Increases as LAN speeds increase– Low attenuation is essential for error free signals

over long cable runs

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ATTENUATION

• Causes of Attenuation– Increase in cable distance– Cable termination equipment

• blocks, jacks, etc.

– Cable termination techniques• pair separations, untwisting, unsheathing

– Increase in signaling frequency– Shielding a cable

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CAPACITANCE

• Capacitance– Refers to a cable’s ability to store an electrical

charge (pf per foot)– Mutual capacitance is measure between two

wires of a pair– Rounds the square wave of a digital signal– Related to dielectric content and thickness of

insulation

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CAPACITANCE AND ATTENUATION

• Capacitance and Attenuation Combined– Combined effect is least desirable– If capacitance is high signal never reaches 1 state

before decline– Signal becomes unreadable to the receiver– For error free transmission attenuation and

capacitance need to be as low as possible

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SRL/IMPEDANCE

• Structural Return Loss (SRL) / Impedance– SRL & Impedance are a measure of uniformity

(flawlessness) of the cable media over the length.– Low SRL values ensure improved component

matching and fewer system mismatch reflections.– Non-uniformities cause signal energy to be back

to the sending device, resulting in signal loss and crosstalk.

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IMPEDANCE

• Impedance– Measure of resistance at a given frequency.– Electrical requirements of the hardware dictate

the impedance value of LAN cables– Impedance mismatches cause signal reflections

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CABLE IMPEDANCE

• UTP cable - 100 Ohms +/-15%• STP cable - 150 Ohms +/-10%• Coaxial cables

– RG58 - 50 Ohms– RG59 - 75 Ohms– RG62 - 93 Ohms

98

CROSSTALK / NEXT• Crosstalk / Near-End Crosstalk

– Crosstalk refers to the coupling of a signal from one pair to another, resulting in “noise” and, thus, an unreadable signal.

– Capacitivity & Inductive Coupling are reduced by controlling the conductor spacing and by using different twist lengths for each pair, respectively.

– Measurement of a signal coupled by transmitting pair to adjacent pairs

– Critical in high speed LANs– NEXT is significant parameter in LAN cable– NEXT is primary source of noise in cable– NEXT is expressed in dB for cable and connecting hardware– The higher the dB value for NEXT the better

• More resistance to coupled signals.

99

SIGNAL TO NOISE RATIO

• SNR– For a LAN to be error free it must operate within

the attenuation and NEXT specifications– Combination of attenuation and NEXT is known as

signal to noise ratio– SNR is the difference between the attenuated

signal and the coupled signal represented by NEXT

100

LAN SNR

• LAN should be designed to the attenuation and NEXT parameters

• Minimum allowed SNR– Token Ring - 12 dB– 10baseT - 10dB

• Ideal if the SNR is 15 dB or greater

101

UTP PERFORMANCE ATTRIBUTES

• Performance Benefits Conclusion– AttenuationAttenuation: Average margin 5% better than

required– SRLSRL: Average margin 5 dB better than standard– NEXTNEXT: Average margin 8 dB better than standard– Signal to Noise MarginSignal to Noise Margin: 35% greater than required

at 31.25 MHz for 100 Mbps transmission

102

UTP PERFORMANCE PARAMETERS

QUESTIONS?

103

UTP CABLE INSTALLATION

NETWORK CABLE SOLUTIONSMODULE 2-C

104

UTP INSTALLATION

• Scope– To provide the installer with the guidelines to

properly handle high grade UTP cable during installation.

– Proper handling assures optimum cable performance for intended present and future applications.

105

UTP INSTALLATION

• Cat 5e Performance– All Data Cable cables have “headroom” built into

its performance characteristics.• Crosstalk loss typically 8 dB/kft. more than the required

minimum per standards.• Signal attenuation typically 5% below the required

maximum by standards.• Signal to crosstalk margin typically 35% greater at 31.25

Mhz than the required minimum per standard.

106

UTP INSTALLATION

• Cat 5e Performance– The headroom assures that the installer is not

working at the edge of the performance envelope of the cable. This assures that some error in the installation may be absorbed.

– This does not mean we can be sloppy in our installation techniques.

107

UTP INSTALLATION

• Construction– Pairs are twisted more tightly and built to specific

design constraints in a Cat. 5e cable.– A precise twist is induced into the bundle 4-Pairs

prior to jacketing.– Geometry becomes critical to maintain

performance.– Damaging or changing the position of the pairs

adversely affects the ability of the cable to carry high data rates.

108

UTP INSTALLATION

• Minimum Bend Radius– Never exceed the minimum bend radius. For a high

performance cable the radius will not be less than eight times the diameter. In a Cat. 5e cable the cable may not be bent less than 1.25 inches.

– Cables exceeding the minimum bend radius will exhibit degraded performance.

– Returning flawed section to a larger diameter will not correct the fault.

• the cable will still exhibit the degraded transmission performance

109

UTP INSTALLATION• Pull cable carefully from box

or reel to avoid kinks and knots

• Pull cable carefully, so as to not induce twist into the cable lengths

110

UTP INSTALLATION

• Minimum Bend Radius– Review conduit bends– Exercise care in installing cable in trays– Do not bend cable over corners– Do not coil cable tightly and stuff into work box

• Store excess coiled in ceiling

– Exercise care when dressing cables

111

UTP INSTALLATION• Avoid exceeding the

minimum bend radius when dressing cables

112

UTP INSTALLATION• When dressing cables,

sweep cables

113

UTP INSTALLATION

• Minimum Bend Radius– Sweep cables to avoid bends and kinks

• Kinking the cable changes the shape of the core, moves the pairs and changes the geometry

• Damage is permanent

• Service Loops– 1-3 foot loops at termination points– Leave service loops along the route of the cable

114

UTP INSTALLATION

• Maximum Tensile Loading– Exceeding the maximum tensile loading will

adversely affect the performance of the cable.• Quality of the cable is affected long before damage is

visible

– Physical stress must be guarded against during installation and in suspended cable runs.

115

UTP INSTALLATION

• Maximum Tensile Loading– Cables should be well supported.– Correcting cable tension will not reverse the effect

of over-loading.– Maximum cable loading for 4-pair Cat. 5e cable is

25 lbs.– Maximum cable loading for 25-pair Cat 5e cable is

160 lbs.

116

UTP INSTALLATION

• Over-Cinching– Over-cinching causes compression and distortion

of the cable, degrading cable performance.• Cable ties must never distort the jacket• Avoid using staples

– Never crush the cable with staples.

117

UTP INSTALLATION• Avoid using staples because

they crush the cables

118

UTP INSTALLATION• Tie wraps should not distort

the jacket of the cable.• A properly installed tie wrap

can easily be moved up and down and twisted around the bundle.

119

UTP INSTALLATION

• Over-Cinching– Select non-compressing cable management

accessories• Velcro tie wraps• “D” rings• Nail on cable clamps

120

UTP INSTALLATION

• Cable Bundles– Assure that weight of bundle is not compressing

cable jacket.– Exert care when running a large cable bundle

around a bend.– In trays fiber cable should be placed on the top

and UTP on the bottom.

121

UTP INSTALLATION

• Cable Lengths– Horizontal runs are limited to 90 meters (295 feet)

or less.– Work area equipment cables are limited to 3

meters or less.– Patch cords, jumpers, and cross connects are

limited to 7 meters or less in the telecommunications closet.

122

UTP INSTALLATION

• EMI/RFI– Avoid all sources of EMI and RFI in the cable

route.– Maintain 5 inches (12 cm) separation from all

fluorescent lighting ballasts.– Never run data cable and power cable together in

a pathway without a barrier.

123

UTP INSTALLATION

• Other Installation Suggestions– Do not run cables in parallel with power wiring

without adequate separation.– Do not share bore holes with power wires.– When installing outlet boxes on studs maintain

proper separation between power and communications cable.

– Never install components of unknown or questionable manufacturer or quality.

124

UTP INSTALLATION

• Other Installation Suggestions– Keep wire away from heat sources, heat ducts and

pipes.– Leave one to three foot service loops at outlets

and connection points.– When exiting a cable tray it is recommended that

a service in a dropped ceiling.– Use proper support methods when installing a

cable in a dropped ceiling

125

UTP INSTALLATION

• Cable Installation– Each horizontal run should be a continuous link to

a single work area.– Bridging of horizontal runs is not acceptable.– Do not split pairs between multiple outlets.

• All four pairs must be connected to a single jack or connector

126

UTP INSTALLATION GUIDE

QUESTIONS?

127

UTP CABLE TERMINATION

NETWORK CABLE SOLUTIONSMODULE 2-D

128

UTP TERMINATION

• Termination– Only two wiring configurations are approved by

the standards.• T568A• T568B

– Choose one configuration and use it throughout the installation.

129

UTP TERMINATION

130

Wiring Configurations

UTP TERMINATION

• Connecting Hardware– All connecting hardware must be the same

category (or better) as the cable.– A link is rated according to the lowest category

component.

131

UTP TERMINATION

• Pair Twists– Pair twists are absolutely critical to cable

performance.• Do not untwists more than 0.5 inches (1.2 cm) from the

point of termination in a Cat. 5e cable (Per TIA 568A).– Untwisting the pairs causes immediate performance

deterioration.– Re-twisting will not restore performance.– Over twisting the cable at the termination does not

help the performance.• distorts the geometry

132

UTP TERMINATION

133

UTP TERMINATION

• Cable Jacket– The cable jacket should be left intact on the cable

to the furthest point possible.• Helps maintain relationship between pairs• Isolates the pairs from different cables• Physically protects the cable from damage

– Guideline.• Strip back only 1 inch (2.5 cm) of the outer jacket

(hardware permitting).

134

UTP TERMINATION

• Station Outlet– Leave minimum of 1-3 feet of slack in the work

box.– Service loops should be stored in the ceiling or in a

double gang box.

135

UTP TERMINATION

• Punch Down1. Strip cable jacket back approximately 2 inches. Be careful not to damage the conductors.2. Hold pairs firmly where they exit the jacket. Position pairs left to right, blue, orange, green, brown.3. Fit pairs over the steeples without untwisting.4. Give pair end a gentle tug, to seat the twist.5. Using a single position punch down tool, punch each pair.

136

UTP TERMINATION

• Cable Management– Cables should be routed and terminated starting

in the center of a patch panel.– Cable should be routed to both ends of a cable

rack rather than one side only to facilitate cable management.

– Watch for cable stress in routing of cables.

137

UTP TERMINATION

QUESTIONS?

138

UTP CABLE TESTING

NETWORK CABLE SOLUTIONSMODULE 2-E

139

UTP TESTING

• Standards– TSB-67 Field Testing Standards for Cat 5e UTP

• Intended to standardize methods for field certification of installed cabling against TIA-568-A category limits (i.e. Category 5e)

– Defines• Test Configurations• Required test functions• Minimum accuracy requirements• Pass/fail criteria

140

UTP TESTINGTIA/EIA TSB 67 - BASIC LINK TESTING

141

UTP TESTINGTIA/EIA TSB 67 - CHANNEL LINK TESTING

142

UTP TESTING

• TSB-67 Test Configurations– Basic Link

• Covers only the permanent portion of cable run• Intended primarily for cable plants that must be tested

before patch cords and network equipment are installed.

– Channel Link• Measures end-to-end cable run performance• More complete test coverage.

– Pass/fail limits are different for each type of link

143

UTP TESTING

• TSB-67 Required Tests– Wire Map

• Tests for correct end to end pin-out

– Length• Tests for 90 meter maximum for permanent portion of

installed link and for 100 meters for overall channel.

144

UTP TESTING

• TSB-67 Required Tests– Attenuation

• Tests from 1 to 100 MHz per the limits of the tested configuration

– Near End Crosstalk• Tests from 1 to 100 MHz per the limits of the tested

configuration• NEXT must be tested from both ends

– To assure that worst case is a pass.

145

UTP TESTING

• TSB-67 Required Tests– In order for the cable run to be rated category 5, it

must pass all four tests• Many manufacturers build additional testing

capabilities into their test equipment. These are excellent diagnostic tools.

– “Pass*” Warnings• Any test that passes but produces a result that is within

the accuracy limit of the tester must carry a warning (*) in indicate that it is marginal.

146

UTP TESTING

• TSB-67 Accuracy Requirements– Defines 2 levels of accuracy

• Level I– Next Accuracy +/-3.4 dB or better– Attenuation Accuracy +/-1.3dB or better

• Level II– Next Accuracy +/-1.6 dB or better– Attenuation Accuracy +/-1.0 dB or better

• Levels I & II– Length Accuracy +/- 1 meter

147

UTP TESTING

• Nominal Velocity of Propagation (NVP)– Speed at which a signal travels through the cable.

• Dependent on materials used and construction• Different from manufacturers to manufacturer.• Listed in product documentation.

– Must be set on test equipment.• Incorrect setting will give incorrect results on length

and attenuation tests.

148

UTP TESTING

• Nominal Velocity or Propagation (NVP)– If the NVP for a cable in unknown:

• Take a known length of cable that is at least 100 feet long.

• Measure the cable with the tester.• Adjust the NVP on the tester until the tester shows the

correct length.• Use this NVP for remainder of tests on that particular

cable.

149

TROUBLESHOOTING• Line Map Failure

– Error: One or more pins open• Causes:

– Broken wire– Bad punch down– Defective jack or plug

– Error: Shorted Pins• Causes:

– Conductors touching at the connector– Pin or circuit defect in the jack or plug.– Cable has been damaged, conductors shorted

– Error: Miswired Pins• Causes:

– Conductors miswired at the connector or jack.

150

TROUBLESHOOTING

• Length failures– Causes:

• Too much cable installed• Incorrect NVP• Installed matched termination not functioning correctly• Cable insulation damage• Near open or near short conditions

– Note that electrical length on a twisted pair cable is longer than jacket length.

151

TROUBLESHOOTING

• Mutual Capacitance and Average Impedance Failure– Causes:

• Compression, stretching, or bending damage to the cable

• Defective connectors• Insulation damage at a connector• Ground loops created between cable shield (if any) and

equipment ground• improperly specified cables or patch cords

152

TROUBLESHOOTING• Attenuation Failure

– Causes:• Cable or patch panels not appropriate for the Category• Poor punch down• Cable length• Worn jack or connector• NVP not set correctly (too low)• Split pairs

• Near-End Crosstalk (NEXT) Failure– Causes:

• Cable or patch cords not rated for the Category• Defective cable• Poor quality installation of connectors, jacks or punch downs• Split pairs

153

UTP TESTING

QUESTIONS?

154

FIBER OPTIC PERFORMANCEPARAMETERS

NETWORK CABLE SOLUTIONSMODULE 2-F

155

FIBER PERFORMANCE ATTRIBUTES

• Attenuation• Bandwidth• Fiber Geometry• Numerical Aperture (NA)

156


• Attenuation– The loss of signal magnitude with respect to distance– Conventional Wavelengths:

• 850mm & 1300nm, Multimode• 1300nm & 1550nm, single-Mode

– For any data rate, loss remains constant at a given wavelength

– Low attenuation values are desired for any wavelength, I.e., the lower the attenuation value, the more signal is received.

157

FIBER PERFORMANCE ATTRIBUTES• Bandwidth

– The carrying capacity of fiber, bandwidth is related to data rate but is defined an items of the bandwidth length product. It is the frequency at which the received magnitude drops to 1/2 of its transmitted level.

– Conventional Wavelengths: • 850mm & 1300mm, multimode• 1310mm & 1550mm, singlemode

– Dispersion the critical cause of limited capacity, increases with frequency the higher the frequency, the smaller the wavelength

– A higher bandwidth value is cleared for any wavelength I.e., higher bandwidth measure increased carrying capacity and higher possible data rate

158


• Fiber Geometry– Analogous parameters to Impedance and

Structural Return Loss (SRL) in twisted pair cables– Tight tolerances assure uniformity and the ability

to make different components in a system– Most optical loss in a typical system link is due to

connector losses from mismatched fiber sectors.

159


• Performance Benefits– Attenuation:Attenuation: Lower attenuation is always desirable. Less

signal loss means that greater distances are possible within link loss budgets.

– Bandwidth:Bandwidth: Higher bandwidth is equivalent to higher data rates. Cables installed today will be capable for network upgrades with increasing system capacity demands.

– Geometry:Geometry: Tighter tolerances in fiber geometry enable better splices and connections with less loss. Greater network reliability and performance for current and future applications

160

LIGHT SOURCES

• Types– Light Emitting Diodes– Laser Diode

• Wavelength of light sources– Multimode fiber

• 850 nm and 1300 nm

– Singlemode fiber• 1310 nm and 1550 nm

161

FIBER COUNTS

• Fiber count varies based on– Number of buildings on a campus (backbone) – number of users in an area (horizontal)– Technology– Topology– Number of connections to backbone– Redundancy planned

• Future growth must be considered

162

ADDITIONAL PLANNING CONSIDERATIONS

• Campus Backbone should be planned with a significant growth factor because of expense in installing additional cable.

• Redundancy• Recommended that hybrid cables that include

singlemode and multimode fiber be included in the inter-building cable plant.

163

FIBER OPTIC MISMATCH

• Mismatch between fiber sizes will create large losses if larger fiber is launching into smaller fiber

• Situation arises in extensions of cable plants to existing facilities

• Not recommended.

164

FIBER OPTIC MISMATCH LOSSES

Transmit Fibers 50um 62.5um100um

Receive 50 um 0.0 2.2 5.7Fibers 62.5 um 0.0 0.0 2.3

100 um 0.0 0.0 0.0

165

FIBER OPTIC PERFORMANCE ATTRIBUTES

QUESTIONS?

166

FIBER OPTIC CABLE INSTALLATION

NETWORK CABLE SOLUTIONSMODULE 2-G

167

FIBER OPTIC INSTALLATION

• Scope– To provide installation guidelines for fiber optic

cable to assure proper optical and mechanical performance.

168


• Fiber Cable Performance– Fiber optic cable has built in “headroom”.

• At 1300 nm the attenuation does not exceed 1.0 dB/km (0.5 dB/km less than the maximum the standard calls for)

• The nominal bandwidth at 1300 nm, is 800 MHz-km (The standard calls for 500 MHz-km)

169


• Pre-Pull Meeting– It is recommended that prior to installation a

meeting be held with all personnel involved in handling the cable.

• Identify the load bearing members of the cable• Review the UL marking and the print legend• Perform a continuity test• Review the bend radius• Review the tensile load

170


• Minimum Bend Radius– Maintain minimum bend radius

• Under tension• Long term

– Minimum bend radius for a cable depends on the series and the fiber count.

– Minimum bend radius should be followed for all cable listed in product catalog.

171


• Minimum Bend Radius– Bending the cable below the minimum bend

radius can:1. Damage the cable jacket.2. Induce higher than desired stress on the fiber.3. Shorten the life of the fiber.

172


• Pulling Cable– Load in pulling must be applied to the all parts of

the cable.• OP and HD type cables are rugged• IC and low count PD type cable require special

installation procedure.

– Failure to lock the cable components together can lead to elongation of the jacket material.

173


• Maximum Tensile Load– Maximum tensile load of a cable should not be

exceeded during the cables installation.– Maximum long term tensile load should not be

exceeded.– Maximum tensile load depends on cable series

and fiber count.– Cable catalog lists maximum tensile loads for all

cables manufactured.

174


• Minimizing Tensile Loads– Changes in cable direction have a greater effect

on cable loads than the length of the cable pull.• Use center pulling or back feeding methods with pulls

longer than 400 meters.• Minimize pulls through 90 degree bends (maximum of

two bends).• Monitor cable tension during cable pulls when using

winches.

175


• Other Installation Suggestions– Leave service loops along the route of the cable.– Loose tube gel filled cables require break out kits

if they are not terminated in a splice tray.– Cables should not hang freely for long distances.

176


• Innerduct– Innerduct facilitates the installation of cable at a

future date.– Eliminates the chance for damage when new

cables are installed in the future.– Serves in a cable management function.– Inner duct and duct are considered full when they

are:• 40% full for multiple cables.• 50% full for single cables.

177

FIBER OPTIC CABLE INSTALLATION

QUESTIONS?

178

OPTICAL FIBER TERMINATION

NETWORK CABLE SOLUTIONSMODULE 2-H

179


• Scope– To review the procedures for proper termination

of optical fiber cable.

180


• Safety Procedures– Always wear safety glasses.– Keep track of and dispose of bear fiber ends

properly– If cable end is attached to electronic transmission

equipment, do not look directly into the fiber.

181


• Polish Inspection– Once the termination is complete the connector

should be inspected using a handheld microscope.

182

OPTICAL FIBER TERMINATION• ST Termination

– Place strain relief and crimp sleeve on cable or on subunit.– Strip off approximately 2-3 inches (4-6cm) of the outer

jacket.– Twist the Kevlar strength member, cut of excess leaving a

short piece per chart provided by the connector manufacturer.

– Fiber subunit prepared.– Using manufacturer supplied template mark the buffer at

the appropriate place for stripping.– Strip off appropriate length of buffer from fiber.– Load connector body with one part of epoxy.

183


• ST Termination– Paint fiber end with part 2 of the epoxy– Immediately fit the connector over the fiber and

seat it against the buffer.– Crimp the sleeve over the back body of the

connector capturing the Kevlar.

• Procedures for other types of connectors are similar to the ST.

184


• Breakout Kits– All loose tube gel filled cables require a breakout

kit to be installed if the fibers are going to be directly terminated.

• Cable and fibers need to be completely cleaned• Protective tubes must be placed over the fiber• Cable tube and breakout tubes must be anchored

– Protect fibers from abrasion

185


• Other methods of jointing fibers include:– Mechanical splices.

• Cleave both fibers.• Place into alignment sleeve or V block.• Crimp or epoxy in place.

– Fusion splices.• Cleave both fibers.• Align fibers on fusion splicer.• Fuse.• Place in protective tray.

186


QUESTIONS?

187

OPTICAL FIBER TESTING

NETWORK CABLE SOLUTIONSMODULE 2-I

188


• Standards– TIA/EIA-568-A, Annex H

• Provides guidelines for testing fiber optic cable plants.• The annex is informative only.• Provides guidelines for testing methods and acceptable

values.• Addresses 62.5/125 and single mode fiber.• Addresses Horizontal and Backbone cable plants

189


• Power Meter Test Method– One Reference Jumper Test Method

• Referenced in TIA/EIA-568-A• Described in ANSI/TIA/EIA-526-14A, Method A

190

FIBER OPTIC TESTING

• Horizontal Links– Links less than 90 meters should be tested at 850

nm OR 1300 nm.– Links greater than 90 meters should be tested at

850 nm AND 1300 nm.– Both can be tested in one direction.

191

FIBER OPTIC TESTING

• Test Results Horizontal Link– 90 meters or less.

• 2.0 dB for the link at 850 nm or 1300 nm.

– Greater than 90 meters.• 2.6 dB for the link at 850 nm• 2.0 dB for the link at 1300 nm

192

FIBER OPTIC TESTING

• Backbone Links– Tested at both wavelengths

• Multimode– 850 nm and 1300 nm

• Singlemode– 1310 nm and 1550 nm

– Tested in one direction

193

FIBER OPTIC TESTING

• Cable Attenuation– Attenuation coefficient 62.5/125 um

• 3.75 dB/km @ 850 nm• 1.5 dB/km @ 1300 nm

– Attenuation coefficient singlemode outside• 0.5 dB/km @ 1310 nm and 1550 nm

– Attenuation coefficient singlemode indoor• 1.0 dB/km @ 1310 nm and 1550 nm

cable attn (dB)=attn coefficient (dB/km)*length (km)

194

FIBER OPTIC TESTING

• Connector Attenuation– Attenuation per connector pair

• 0.75 dB– Attenuation per link

• Each link has two pairs• 1.5 dB is value always used for the connector

attenuation.

Connector attn (dB) = number pairs * connector loss (dB)

195

FIBER OPTIC TESTING

• Splice Attenuation– Loss per Splice

• 0.3 dB

splice attn (dB) = number splices * splice loss (dB)

• Link Attenuation EquationLink Attenuation = Cable Attn + Connector Attn + Splice

Attn

196

FIBER OPTIC TESTING

• System Links– If a system link is made up of two or more passive

links then the expected loss for the system link is the sum of the passive links attenuation.

197

FIBER OPTIC TESTING

• Cable Lengths– During installation it is advisable to accurately

document the length of all links installed.• Reporting Documentation

– Horizontal• Path Identification• Measured loss at required wavelength

– Backbone• Path Identification• Acceptance values at both wavelengths.• Measured loss at both wavelengths.

198

FIBER OPTIC TESTING

• Troubleshooting– Excessive link loss.

• Clean connectors on installed cable.• Clean connectors on jumpers.• Clean adapters on test equipment.• Inspect connectors polished ends for damage.• Recalibrate power meter.• Re-terminate

199

FIBER OPTIC TESTING

• Bandwidth– Field testing of fiber bandwidth not done

• Field usable test equipment not available– Discontinued equipment was not accurate

• Bandwidth (and dispersion in single mode fibers) is not adversely affected by installation techniques.

– Bandwidth and dispersion is measured by the manufacturer.

200

FIBER OPTIC TESTING

• OTDR (Optical Time Domain Reflectometer)– Additional testing can be carried out using an

OTDR.• Recommended on backbone cabling.

– Results include• Length• Attenuation• Splice Losses• Stress Points

– Excellent Diagnostic Tool

201

OTDR TESTING

• OTDR Testing is detailed in the EIA/TIA Standard FOTP-61.

202


QUESTIONS?

203

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