thinnet (10base2) characteristics (cont.): size and scalability size and scalability allows a...
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Thinnet (10Base2)Thinnet (10Base2)
Characteristics Characteristics (cont.):(cont.): Size and scalabilitySize and scalability
Allows a maximum Allows a maximum of 185 m per of 185 m per network segment network segment (see Figure 4-20)(see Figure 4-20)
Noise immunityNoise immunityMore resistant than More resistant than twisted-pair wiringtwisted-pair wiring
Less resistant Less resistant ThicknetThicknet Figure 4-19: Thinnet BNC connectors
Thinnet (10Base2)Thinnet (10Base2)
Signal bounceSignal bounce Caused by Caused by
improper improper termination on termination on a bus networka bus network
Travels Travels endlessly endlessly between two between two ends of ends of networknetwork
Prevents new Prevents new signals from signals from getting throughgetting through
Figure 4-20: A 10Base2 Ethernet network
Twisted-Pair (TP) CableTwisted-Pair (TP) CableColor-coded pairs of Color-coded pairs of insulated copper wires insulated copper wires twisted around each twisted around each other and encased in other and encased in plastic coatingplastic coating
Twists in wire help Twists in wire help reduce effects ofreduce effects of crosstalkcrosstalk
Number of twists per Number of twists per meter or foot known as meter or foot known as twist ratiotwist ratio
Alien CrosstalkAlien Crosstalk When signals from When signals from
adjacent cables interfere adjacent cables interfere with another cable’s with another cable’s transmissiontransmission
Figure 21: Twisted-pair cable
Shielded Twisted-Pair (STP)Shielded Twisted-Pair (STP)
STP cable consists of twisted wire pairs that are STP cable consists of twisted wire pairs that are individually insulated and surrounded by shielding individually insulated and surrounded by shielding made of metallic substancemade of metallic substance
Figure 4-22: STP cable
Unshielded Twisted-PairUnshielded Twisted-Pair
Consists of one or more insulated wire pairs Consists of one or more insulated wire pairs encased in a plastic sheathencased in a plastic sheathDoes not contain additional shieldingDoes not contain additional shielding
Figure 4-23: UTP cable
Unshielded Twisted-PairUnshielded Twisted-Pair
To manage To manage network cabling, it network cabling, it is necessary to be is necessary to be familiar with familiar with standards used on standards used on modern networks, modern networks, particularly particularly Category 3 (CAT3) Category 3 (CAT3) and Category 5 and Category 5 (CAT5)(CAT5)
Figure 4-24: A CAT5 UTP cable
Unshielded Twisted-PairUnshielded Twisted-Pair
CAT1 – 2 wire pairs; suitable for voice onlyCAT1 – 2 wire pairs; suitable for voice onlyCAT2 – 4 wire pairs; up to 4 Mbps throughputCAT2 – 4 wire pairs; up to 4 Mbps throughputCAT3 – 4 wire pairs; up to 10 Mbps and 16 Mhz CAT3 – 4 wire pairs; up to 10 Mbps and 16 Mhz signalsignalCAT4 – 4 wire pairs; up to 10 MbpsCAT4 – 4 wire pairs; up to 10 MbpsCAT5 – 4 wire pairs; up to 100 Mbps and 100 Mhz CAT5 – 4 wire pairs; up to 100 Mbps and 100 Mhz signalsignalCAT5e – up to 200 Mhz signalCAT5e – up to 200 Mhz signalCAT6 – additional foil insulation; 6x throughput than CAT6 – additional foil insulation; 6x throughput than CAT5CAT5CAT7 – unfinished standard – up to 1GhzCAT7 – unfinished standard – up to 1Ghz
10BaseT10BaseTPopular Ethernet networking standard that replaced 10Base2 and 10Base5 Popular Ethernet networking standard that replaced 10Base2 and 10Base5 technologiestechnologies““T” for twisted pairT” for twisted pair
Figure 4-25: A 10BaseT Ethernet network
10BaseT10BaseT
Enterprise-wide Enterprise-wide networknetwork
Spans entire Spans entire organizationorganization
Often services Often services needs of many needs of many diverse usersdiverse users
Figure 4-26: Interconnected 10BaseT segments
100BaseT100BaseT
Enables LANs to run at 100-Mbps data Enables LANs to run at 100-Mbps data transfer ratetransfer rate
Also known as Also known as Fast EthernetFast Ethernet
Two 100BaseT specifications have competed Two 100BaseT specifications have competed for popularity as organizations move to 100-for popularity as organizations move to 100-Mbps technology:Mbps technology: 100BaseTX100BaseTX 100BaseT4 (can use CAT3 cabling)100BaseT4 (can use CAT3 cabling)
100BaseVG100BaseVG
Cousin of Ethernet 100 Mbps technologiesCousin of Ethernet 100 Mbps technologies
VG stands for voice gradeVG stands for voice grade
Also called 100VG-AnyLANAlso called 100VG-AnyLAN
Originally developed by Hewlett-Packard Originally developed by Hewlett-Packard and AT&Tand AT&T
Now governed by IEEE standard 802.12Now governed by IEEE standard 802.12
Requires more sophisticated NICs and Requires more sophisticated NICs and can reduce network performancecan reduce network performance
Comparing STP and UTPComparing STP and UTP
ThroughputThroughput Both can transmit up to 100 MbpsBoth can transmit up to 100 Mbps
CostCost Typically, STP is more expensiveTypically, STP is more expensive
ConnectorConnector Both use Both use RJ-45RJ-45 connectors and data jacks connectors and data jacks
Noise immunityNoise immunity STP is more noise-resistantSTP is more noise-resistant
Size and scalabilitySize and scalability Maximum segment length for both is 100 metersMaximum segment length for both is 100 meters
Fiber-Optic CableFiber-Optic Cable
Contains one or Contains one or several glass several glass fibers at its fibers at its corecore Surrounding Surrounding
the fibers is a the fibers is a layer of glass layer of glass called called claddingcladding
Figure 4-28: A fiber-optic cable
Fiber-Optic CableFiber-Optic Cable
Single-mode Single-mode fiberfiber Carries light Carries light
pulses along pulses along single pathsingle path
Multimode fiberMultimode fiber Many pulses of Many pulses of
light generated light generated by LED travel at by LED travel at different anglesdifferent angles Figure 4-29: Single-mode and
multimode fiber-optic cables
Fiber-Optic CableFiber-Optic Cable
ThroughputThroughput Reliable in transmitting up to 1 gigabit per Reliable in transmitting up to 1 gigabit per
secondsecond
CostCost Most expensive type of cableMost expensive type of cable
ConnectorConnector You can use any of 10 different types of You can use any of 10 different types of
connectorsconnectors
Fiber-Optic CableFiber-Optic Cable
Two popular connectors used with fiber-optic cable:Two popular connectors used with fiber-optic cable: ST connectorsST connectors SC connectorsSC connectors
Figure 4-30: ST and SC fiber connectors
Fiber-Optic CableFiber-Optic Cable
Noise immunityNoise immunity Unaffected by either EMI or RFIUnaffected by either EMI or RFI
Size and scalabilitySize and scalability Network segments made from fiber can span Network segments made from fiber can span
100 meters100 meters Signals transmitted over fiber can experience Signals transmitted over fiber can experience
optical lossoptical loss
10BaseF and 100BaseFX10BaseF and 100BaseFX
10BaseF10BaseF Physical layer standard for networks Physical layer standard for networks
specifying baseband transmission, specifying baseband transmission, multimode multimode fiber cablingfiber cabling, and 10-Mbps throughput, and 10-Mbps throughput
100BaseFX100BaseFX Physical layer standard for networks Physical layer standard for networks
specifying baseband transmission, specifying baseband transmission, multimode multimode fiber cablingfiber cabling, and 100-Mbps throughput, and 100-Mbps throughput
Physical Layer Networking Physical Layer Networking StandardsStandards
Table 4-3: Physical layer networking standards
Cable Design and ManagementCable Design and Management
1991 – TIA/EIA released its joint 568 1991 – TIA/EIA released its joint 568 Commercial Building Wiring StandardCommercial Building Wiring Standard TIA – Telecommunication Industry Assoc.TIA – Telecommunication Industry Assoc. www.tiaonline.orgwww.tiaonline.org EIA – Electronic Industries Assoc.EIA – Electronic Industries Assoc. www.eia.orgwww.eia.org
T568AT568A
T568BT568B
Cable Design and ManagementCable Design and Management
Cable plantCable plant Hardware Hardware
comprising comprising enterprise-wide enterprise-wide cabling systemcabling system
Structured cablingStructured cabling Method for Method for
uniform, uniform, enterprise-wide, enterprise-wide, multivendor multivendor cabling systemscabling systems
Figure 4-31: TIA/EIA structured cabling subsystems
Cable Design and ManagementCable Design and Management
Entrance facilitiesEntrance facilitiesBackbone wiringBackbone wiring Backbone cabling that provides vertical connections Backbone cabling that provides vertical connections
between floors of a building are called between floors of a building are called risersrisers
Table 4-4: TIA/EIA specifications for backbone cabling
Cable Design and ManagementCable Design and Management
Equipment roomEquipment room
Telecommunication Telecommunication closetcloset Punch-down Punch-down
blockblock is a panel of is a panel of data receptorsdata receptors
Patch panelPatch panel is a is a wall-mounted panel wall-mounted panel of data receptorsof data receptors
Figure 4-32: Patch panel (left) and punch-down block (right)
Cable Design and ManagementCable Design and Management
Horizontal wiringHorizontal wiringMax distance is 100mMax distance is 100m
Figure 4-33: Horizontal
wiring
Cable Design and ManagementCable Design and Management
Work areaWork area Patch cablePatch cable is a is a
relatively short relatively short section of twisted-section of twisted-pair cabling with pair cabling with connectors on both connectors on both ends that connect ends that connect network devices to network devices to data outletsdata outlets
Figure 4-34: Standard TIA/EIA wall jack
Cable Design and ManagementCable Design and Management
Figure 4-35: A structured cabling hierarchy
Installing CableInstalling Cable
Figure 4-36: A typical UTP
cabling installation
Installing CableInstalling Cable
Table 4-5: Pin numbers and color codes for an RJ-45 connector
* T568A Standard
Installing CableInstalling Cable
Straight-through cableStraight-through cable Terminations at both ends are identicalTerminations at both ends are identical
Crossover cableCrossover cable Terminations locations of transmit and receiver wires on one end Terminations locations of transmit and receiver wires on one end
of cable are reversedof cable are reversed
Figure 4-37: RJ-45
terminations on a
crossover
Installing CableInstalling Cable
Do not untwist twisted-pair cables more than Do not untwist twisted-pair cables more than one-half inch before inserting themone-half inch before inserting them
Do not strip off more than one inch of insulation Do not strip off more than one inch of insulation from copper wire in twisted-pair cablesfrom copper wire in twisted-pair cables
Watch Watch bend radiusbend radius limitations for cable being limitations for cable being installedinstalled
Test each segment of cabling with cable testerTest each segment of cabling with cable tester
Use only cable ties to cinch groups of cable Use only cable ties to cinch groups of cable togethertogether
Installing CableInstalling Cable
Avoid laying cable across floor where it Avoid laying cable across floor where it may sustain damagemay sustain damageInstall cable at least three feet away from Install cable at least three feet away from fluorescent lights or other sources of EMIfluorescent lights or other sources of EMIAlways leave slack in cable runsAlways leave slack in cable runs
If running cable in If running cable in plenumplenum, area above , area above ceiling tile or below subflooring, make sure ceiling tile or below subflooring, make sure cable sheath is plenum-ratedcable sheath is plenum-ratedPay attention to grounding requirementsPay attention to grounding requirements
Atmospheric Transmission MediaAtmospheric Transmission Media
Infrared transmissionInfrared transmission InfraredInfrared networks use infrared light networks use infrared light
signals to transmit data through spacesignals to transmit data through space Direct infrared transmissionDirect infrared transmission depends depends
on transmitter and receiver remaining on transmitter and receiver remaining within within line of sightline of sight
In In indirect infrared transmissionindirect infrared transmission, , signals can signals can bouncebounce off of walls, ceilings, off of walls, ceilings, and any other objects in their pathand any other objects in their path
Atmospheric Transmission MediaAtmospheric Transmission Media
RF transmissionRF transmission Radio frequency (RF)Radio frequency (RF) transmission relies transmission relies
on signals broadcast over specific frequencieson signals broadcast over specific frequencies Very susceptible to interferenceVery susceptible to interference Two most common RF technologies:Two most common RF technologies:
NarrowbandNarrowband Concentrates RF energy at a single frequencyConcentrates RF energy at a single frequency
Spread spectrumSpread spectrum Distributed over several frequencies simultaneouslyDistributed over several frequencies simultaneously
Choosing the Right Transmission Choosing the Right Transmission MediaMedia
Areas of high EMI or RFIAreas of high EMI or RFI
Corners and small spacesCorners and small spaces
DistanceDistance
SecuritySecurity
Existing infrastructureExisting infrastructure
GrowthGrowth