Campus Networking Best Practices

Session 3: Layer 0Campus Network Structured CablingDale SmithUniversity of Oregon & NSRCdsmith@uoregon.edu

We all have some ugly wiring

Structured Cabling SystemsOnly two types of cabling:Unshielded twisted pair copper provides service to individual computers and between network closetsFiber optic cabling provides service to buildings and between network closetsEverything is run in a star configuration

Data closetCore Locationcat5eFiber optic

Unshielded Twisted Pair CableRun in star configuration from Network Closet location to individual outlets in offices or labs.Run at least two cables to every outlet I recommend four if you can afford it.Run at least six cables between network closets if the distance is less than 90 metersQuestion: what type of cable to run? Cat5, cat5e, Cat6, ???

What type of UTPWhat speed does each type support?

Strongly recommend category 5e cabling.

Cable TypeMax SpeedMax DistanceCost FactorCategory 5100Mbs100m1xCategory 5e1000Mbs100m1xCategory 61000Mbs100m1.3xCategory 610,000Mbs57m1.3xCategory 6a10,000Mbs100m2x

Unshielded Twisted Pair CableLabeling is a key to reduce work later

Fiber Optic CablingTwo basic types of fiberMulti Mode limited to 2km @ 100MbsSingle Mode 70km @ virtually unlimitedMultiple types of multi mode62.5 micron core50 micron coreMultiple types of single modeOptimized for 1310 and 1550 nm operationOptimized for WDM operation

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Physics of Fiber

What type of Fiber?Multi mode Fiber62.5 micron100baseFX for 2km, optical interface cost $250 USD1000baseSX for 275m, optical interface cost $250 USD1000baseLX for 500m, optical interface cost $750 USD10GbaseSR for 33m, optical interface cost $2000 USD10GbaseLRM for 220m, optical interface cost $1500 USD (not widely avail)50 micron laser optimized100baseFX for 2km, optical interface cost $250 USD1000baseSX for 550m, optical interface cost $250 USD1000baseLX for 500m, optical interface cost $750 USD10GbaseSR for 300m, optical interface cost $2000 USD10GbaseLRM for 220m, optical interface cost $1500 USD (not widely avail)Single mode Fiber100baseFX not supported1000baseSX not supported1000baseLX for 5km (most vendors support 10km), cost $750 USD1000baseLH (not a standard) 70km with 1550nm lasers, cost $3000 USD10GbaseLR for 10km, optical interface cost $3000 USD10GbaseER for 30-40km, optical interface cost $8500 USD

Going Fast on FiberMulti mode Fiber62.5 micron1Gbs to 500m10Gbs to 220m50 micron laser optimized1Gbs to 500m10Gbs to 300mSingle mode Fiber1Gbs to 70km10Gbs to 70km

Fiber Optic TopologyNeed to install both Multi and Single ModeMulti mode: either 62.5 or 50 micro is acceptableSingle mode: use fiber optimized for 1310/1550nmRun in star configuration from core network location to individual buildingsAlso run in star configuration inside of buildings from main phone closet to other closetsTo reduce costs, can run large fiber cable from core to some remote location, then smaller cables from there to surrounding buildings

Star ConfigurationPlan for future -- Install enough fiberMinimum: 6 multimode plus 6 single mode from core to each buildingMinimum: 6 multimode plus 6 single mode from building entrance network closet to every other network closet in the building.

Core network locationBuilding to be servedNearby buildings

Fiber Optic TopologyNetwork Core LocationNetwork Closet 1Building 3Network Closet 2

Building 1Network Closet 3Building 5Building 4Building 2fiberfiberfiberfiberfiberfiberfiber

Construction HintsUse outdoor cable between buildingsArmored (to protect against rodents)Loose tubeUse indoor cabling inside buildingstight bufferStandardize on ConnectorsMulti mode: ST or SC (epoxy or hot melt)Single mode: SC or LC (fusion Splice factory UPC pigtail)

Fiber Optic Cable ConstructionFiber has bend radius issues

More Construction HintsFor cable installed in underground conduit:No more than 200m between pull pointsReduce distance by 50m for every 90 degrees of bend

Fiber Optic Cable ConstructionLeave slack loops

Putting it all TogetherNetwork Core LocationNetwork Closet 1Building 3Network Closet 2

Building 1Network Closet 3Building 5Building 4Building 2cat5efibercat5eCat5e + fiberCat5e + fiberfiberfiberfiberfiber

How About Going Even Faster?100 Gigabits?Dispersion becomes your enemyEven single mode fiber has dispersionChromatic Dispersion (CD) Even slightly different colors of light travel different speedsPolarization Mode Dispersion (PMD) Slight variations from true roundness causes differently polarized light to travel different distances.

The Solution Today is WDMWave Division Multiplexing (WDM)Provisioning multiple Gigabit or 10 Gigabit using different colors of lightCoarse (CWDM)Fewer waves, low cost1310nm frequency spectrumNot suitable for amplification short haul (70km)Dense (DWDM) more wavesMore waves, higher cost1550nm frequency spectrumSuitable for EDFA amplification long haul (1000s of km)

WDM Simple Single Span

TransmitterTransmitterTransmitterTransmitterReceiverReceiverReceiverReceiverSingle Fiber

ReceiverReceiverReceiverReceiverTransmitterTransmitterTransmitterTransmitterSingle Fiber

Optical Add Drop Multiplexor

TransmitterTransmitterTransmitterTransmitterReceiverReceiverReceiverReceiver

Can Build Complex Networks

Layer 0 SummaryInstall cabling in star configuration dont daisy chainInstall cat5e or cat6a cat6 is a waste of money if the runs are over 57mInstall both single and multi mode fiber for runs over 300m

Thank You

Questions

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