CCNA1_CaseStudy_Structured_Cabling (1130680)
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CCNA – Semester1Case StudyStructured Cabling SupplementObjectives•••••••Structured Cabling SystemsStructured Cabling Standards and CodesSafetyTools of the TradeInstallation ProcessFinish PhaseThe Cabling BusinessStructured Cabling SystemsRules of Structured Cabling for LANs• The first rule is to look for a completeconnectivity solution.• The second rule is to plan for future growth.• The final rule is to maintain freedom of choice invendors.Subsystems of Structured CablingHorizontal cablingScalability• Backbone scalability• Work area scalabilityDemarcation Point• The demarcation point(demarc) is the point atwhich outdoor cablingfrom the serviceprovider connects tothe intrabuildingbackbone cabling.Demarcation Point• It represents the boundary between theresponsibility of the service provider and theresponsibility of the customer.• In many buildings, the demarc is near thepoint of presence (POP) for other utilitiessuch as electricity and water.Telecommunications and Equipment Rooms• After the cable enters the building through the demarc,it travels to the entrance facility (EF), which is usually inthe equipment room (ER).Work Areas• A work area is the area serviced by an individual TR.
Awork area usually occupies one floor or part of one floorof a building.Servicing the work areaTypes of patch cables• Straight-Through, Cross-Over, Roll-Over UTP cable.• T568-A or T568-B StandardCable management• Cable managementdevices are used toroute cables along aneat and orderly pathand to assure minimumbend radius ismaintained.• Cable management alsosimplifies cableadditions andmodification to the wiringsystem.MC, IC, and HC•••The main cross-connect (MC) is the center of the network.The intermediate cross-connect (IC) is connected to the MC andmay hold the equipment for a building on a campus.The horizontal crossconnect (HC) provides the cross-connectbetween the backbone and horizontal cables on a single floor of abuilding.MC, IC, and HCBackbone cabling• Any cabling installed between the MC andanother TR is known as backbone cabling,also called vertical cabling.Backbone cabling• Backbone cabling includes the following:– TRs on the same floor, MC to IC, and IC to HC– Vertical connections, or risers, between TRs on different floors, suchas MC to IC cabling– Cables between TRs and demarcation points– Cables between buildings, or inter-building cables, in a multibuildingcampusFiber-optic backbone• The use of fiber optics is an effective way tomove backbone traffic for these reasons:– Optical fibers are impervious to electrical noise and radiofrequency interference.– Fiber does not conduct currents that can cause groundloops.– Fiber-optic systems have high bandwidth and can work athigh speeds.– Fiber can travel much farther than copper when used as abackbone media.MUTOAs and Consolidation Points• Horizontal cablingmethodologies usingmultiusertelecommunicationsoutlet assemblies(MUTOAs) andconsolidation points(CPs) are specifiedfor open officeenvironments.Structured CablingStandards and CodesTelecommunications Industry Association(TIA) andElectronic Industries Alliance (EIA)• Standards are sets of rules or procedures that are eitherwidely used, or officially specified to provide a model ofexcellence.European Committee for ElectrotechnicalStandardization (CENELEC)• CENELEC develops electrotechnical standardsfor most of Europe.• CENELEC works with 35,000 technical expertsfrom 22 European countries to publishstandards for the European market.International Organization for Standardization (ISO)• International Organization for Standardization (ISO)consists of national standards organizations fromover 140 countries, including ANSI.• ISO is a non-governmental organization thatpromotes the development of standardization andrelated activities.• The work of the ISO results in internationalagreements, which are published as internationalstandards.Evolution of Standards• Many types of older cable are inadequate for use infaster, modern networks.
Therefore, cabling willusually change over time. The TIA/EIA-568-B.2standards reflect this.• For twisted-pair cables, only 100-ohm Category 3,5e, and 6 cables are recognized. Category 5 cable isno longer recommended for new installations.• When terminating Category 5e and higher cables,the pairs should not be untwisted more than 13 mm(0.5 inch) from the point of termination.SafetyMSDS• A material safety data sheet (MSDS) is adocument that contains information about theuse, storage, and handling of a hazardousmaterial.• An MSDS provides detailed information aboutthe potential health effects of exposure and howto work safely with the material.MSDS• MSDS includes the following information:––––––What the hazards of the material areHow to use the material safelyWhat to expect if the recommendations are not followedWhat to do if accidents occurHow to recognize symptoms of overexposureWhat to do if such incidents occurUnderwriters Laboratories (UL)• Underwriters Laboratories (UL) is an independent,nonprofit product safety testing and certificationorganization.• UL has tested products for public safety for over acentury.• The UL focuses on safety standards, but hasexpanded its certification program to evaluatetwisted-pair LAN cables for performance.National Electrical Code (NEC)•The purpose of the National Electrical Code (NEC) is tosafeguard people and property from hazards that arise fromthe use of electricity.Electricity Safety••••••High-voltageLightning and high-voltage dangerHigh-voltage safety testGroundingBondingGrounding and bonding standardsLab and Workplace Safety Practices• Although cable installation is generally a safeprofession, there are plenty of opportunities forinjury.• Many injuries are caused when installers come incontact with stray sources of voltage, or foreignvoltages.• When working in walls, ceilings, or attics, first turnoff power to all circuits that pass through those workareas.• Most countries have agencies that develop andadminister safetystandards.Workplace safety• Before beginning work, learn the locationsof all fire extinguishers in the area.• Always determine the local codes inadvance.• When installing cable between floors, usea riser-rated cable.• Outdoor cables typically have apolyethylene jacket.Workplace safety• The building maintenance engineershould be consulted to determine if thereis asbestos, lead, or PCB in the work area.• If cable must be routed through spaceswhere air is circulated, be sure to use afire-rated, or plenum-rated, cable.Ladder safety• Select the right ladder for the job.
The ladder shouldbe long enough to work from comfortably and sturdyenough to withstand repeated use.• Inspect the ladder first. Never climb higher than thesecond step from the top on a stepladder,• Post signs so that people are aware of the ladder.Fiber-optic safety• Always wear safety glasses with side shields.• Place a mat or piece of adhesive on the tableso that all glass shards that fall are easilyidentified.• Do not touch eyes or contact lenses whileworking with fiberoptic systems until handshave been thoroughly cleaned.Fiber-optic safety• Put all cut fiber pieces in a safe place and disposeof them properly.• Use a piece of adhesive or masking tape to removeany material that gets on clothing.
Use tape toremove shards from fingers and hands.• Do not bring food or beverages in the work area.• Do not look directly into the end of fiber cables.Some laser driven devices could cause irreversibledamage to the eye.Fire extinguisher use• Never attempt to fight a fire without knowing how touse a fire extinguisher.
Read the instructions andcheck the valve.• Class A fires are ordinary materials like burningpaper, lumber, cardboard, and plastics.• Class B fires involve flammable or combustibleliquids such as gasoline, kerosene, and commonorganic solvents used in the laboratory.Fire extinguisher use• Class C fires involve energized electrical equipmentsuch as appliances, switches, panel boxes, powertools, hot plates, and most other electronic devices.Water is a dangerous extinguishing medium forclass C fires because of the risk of electrical shock.• Class D fires involve combustible metals such asmagnesium, titanium, potassium, and sodium.These materials burn at high temperatures and willreact violently with water, air, and other chemicals.Personal Safety Equipment• Work clothes• Eye protection• Hard hat useTools of the TradeStripping and Cutting ToolsTermination ToolsDiagnostic ToolsInstallation Support ToolsInstallation Support ToolsInstallation Support ToolsInstallation ProcessInstallation Process• Rough-In Phase – all of the cables are installed in theceilings, walls, floor ducts, and risers.• Trim Out Phase –cable management and the termination ofwires.• Finish Phase – cable testing, troubleshooting, andcertification.• Customer Support Phase –the customer conducts a walkthrough of the network and is presented with formal testresults and other documentation, like asbuilt drawings.
Ifsatisfied, the customer will sign off on the project. The cableinstallation company will provide ongoing support to thecustomer if there are problems with the cabling.Rough-In Phase• During the rough-in phase the cable is pulled from awork area, or staging area, to individual rooms orwork areas.• Each cable is labeled on both ends for identification.• In the work area, extra cable should be pulled sothat there is plenty to work with when terminating.Rough-In Phase: Horizontal cable installation• Cables should always run parallel to walls.• Cables should never be placed diagonally across aceiling.• The cabling path should be the most direct pathwith the fewest number of turns.• Cables should not be placed directly on top ofceiling tiles.Rough-In Phase: Horizontal cable installation• After the backbone cablinghas been installed, thehorizontal networkdistribution cable must beinstalled.• Horizontal cable installationin conduits• Raceways• Pulling cable to the jacks• Mouting jack in drywall,plaster or woodVertical Cable Installation• Vertical cable installation can include networkdistribution cables and backbone cables.• Most vertical installations are installed in conduits,in conduit sleeves through the floors, or in slots cutthrough the floor.• Vertical cable installation takes place either from anupper floor to a lower floor or from a lower floor toan upper floor.Fire-Stops• The choice of cablingmaterials and how they areinstalled can greatly affecthow a fire moves through abuilding, the type of smokeand gasses emitted, andthe speed at which thesmoke and flames spread.Terminating Copper Media• Communications cables are color-coded to identifyindividual pairs.• The use of color codes ensures uniformity inidentifying individual cable pairs.
Each coloredcable pair is associated with a specific number.Four-pair color codeRJ-45 plugs and jacks110-block•••110-blocks are high-densitytermination blocks that are usedfor either voice or dataapplications.These blocks are designed to bestacked in different combinationsto accommodate different sizerequirements.The 110 system includes wiremanagement devices that alsoact as spacers between theblocks.Terminate or punch down• The termination ofcommunications cables at aTR is referred to aspunching down.• Cables are also puncheddown on termination panelsmounted on wall fields andat the rear of cross-connectpanels.Wire managementCareful labeling• Labeling is another important part of a structuredcabling system.• Cables should be clearly labeled on both ends toavoid confusion.• TIA/EIA-606-A specifies that each hardwaretermination unit should have a unique identifiermarked on the unit or on its label.• Documenting label scheme.Finish PhaseCable Testing••••OpensShortsSplit pairsWire-mappingerrorsTime Domain Reflectometer (TDR)• A time domain reflectometer (TDR) sends a pulsedown the wire and then monitors the electronicechoes that occur due to cable problems.• TDRs will determine if there is a cable fault, andwhether it is an open or a short.• TDRs can also measure the distance from themeter to the fault.Cable Certification• Testing is not the same as certification.
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