How To Determine The Integrity of an Ethernet Line Design Team 7 Mark Jones Sedat Gur Ahmed Alsinan...
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Transcript of How To Determine The Integrity of an Ethernet Line Design Team 7 Mark Jones Sedat Gur Ahmed Alsinan...
How To Determine The How To Determine The Integrity of an Ethernet LineIntegrity of an Ethernet Line
Design Team 7Design Team 7
Mark JonesMark JonesSedat GurSedat Gur
Ahmed AlsinanAhmed AlsinanBrian SchulteBrian Schulte
Andy ChristophersonAndy Christopherson
IntroductionIntroduction
Ethernet History and StructureEthernet History and Structure Time Domain ReflectometryTime Domain Reflectometry Active Link Cable DiagnosticsActive Link Cable Diagnostics Digital Spectrum AnalysisDigital Spectrum Analysis Power-over-Ethernet DetectPower-over-Ethernet Detect Output DataOutput Data
History of EthernetHistory of Ethernet Computer based networking Computer based networking
technology for Local Area Networks technology for Local Area Networks (LANs)(LANs)
Developed by Xerox in Early 70’sDeveloped by Xerox in Early 70’s Used for approximately 85% of world’s LAN-Used for approximately 85% of world’s LAN-
connected PCs and workstationsconnected PCs and workstations Implemented with multiple types of cableImplemented with multiple types of cable
Coaxial Coaxial Twisted PairTwisted Pair Fiber OpticFiber Optic
Twisted Pair WiresTwisted Pair Wires Used in many Ethernet and Used in many Ethernet and
telephone systems telephone systems Receiver takes the difference Receiver takes the difference
between the wire pairbetween the wire pair Any interference in signal will be Any interference in signal will be
canceled outcanceled out AdvantagesAdvantages
Cables are thin, easy to run Cables are thin, easy to run throughout buildingthroughout building
FlexibleFlexible Cheap to manufactureCheap to manufacture
DisadvantagesDisadvantages Resistance to electromagnetic Resistance to electromagnetic
interference depends on pair interference depends on pair twisting scheme usedtwisting scheme used
Twisted Pair StandardsTwisted Pair Standards Category 3Category 3
Up to 10 MbpsUp to 10 Mbps Bandwidth up to 16 MHzBandwidth up to 16 MHz Popular in early 90’sPopular in early 90’s
Category 5Category 5 Used for mainly 100Mbps Used for mainly 100Mbps
networksnetworks Bandwidth up to 100MhzBandwidth up to 100Mhz
Category 5eCategory 5e Enhanced version of Category 5Enhanced version of Category 5 More rigorous standardsMore rigorous standards Recommended for most networksRecommended for most networks
Category 6Category 6 Bandwidth up to 250MHzBandwidth up to 250MHz Recommended for gigabit speedsRecommended for gigabit speeds
So what kind of errors are we So what kind of errors are we looking for?looking for?
Opens and ShortsOpens and Shorts Cable impedance mismatchCable impedance mismatch Bad connectorsBad connectors Terminations mismatchesTerminations mismatches Water damageWater damage Any other discontinuities Any other discontinuities
Also can find cable lengthAlso can find cable length
Time Domain ReflectometryTime Domain Reflectometry
Will diagnose opens, shorts, cable Will diagnose opens, shorts, cable impedance mismatch, bad connectors, impedance mismatch, bad connectors, termination mismatches, etc.termination mismatches, etc.
Uses reflections to find these errors and Uses reflections to find these errors and their locationstheir locations
Time Domain ReflectometryTime Domain Reflectometry
Pulse is transmitted of Pulse is transmitted of known amplitude known amplitude down twisted pairsdown twisted pairs
Reflects off Reflects off imperfections and imperfections and faultsfaults
Measure return time Measure return time and amplitude of and amplitude of reflectionsreflections
Time Domain ReflectometryTime Domain Reflectometry
With the gathered data we can findWith the gathered data we can find Distance and Magnitude (Impedance)Distance and Magnitude (Impedance) Non-terminated Cables (Opens and Shorts)Non-terminated Cables (Opens and Shorts) Discontinuities (Bad Connectors)Discontinuities (Bad Connectors) Improperly Terminated CablesImproperly Terminated Cables
Time Domain ReflectometryTime Domain Reflectometry
Active Link Cable DiagnosticsActive Link Cable Diagnostics
Use of passive digital signal processingUse of passive digital signal processing Will find cable length with active cableWill find cable length with active cable
Uses predefined parameters based on the Uses predefined parameters based on the cable propertiescable properties High accuracy cable lengthHigh accuracy cable length
Spectrum AnalysisSpectrum Analysis
Analog Spectrum AnalysisAnalog Spectrum Analysis Uses a variable band-pass filterUses a variable band-pass filter
Digital Spectrum AnalysisDigital Spectrum Analysis Uses Discrete Fourier TransformUses Discrete Fourier Transform
Results in frequency spectrum of our signalResults in frequency spectrum of our signal
Digital Spectrum AnalysisDigital Spectrum Analysis
Gives magnitude of Gives magnitude of the frequency the frequency responseresponse This will show us how This will show us how
the signal is spread the signal is spread out along the out along the frequency spectrumfrequency spectrum
Allow us to see noise Allow us to see noise along the linealong the line Especially how it Especially how it
relates to the length of relates to the length of the cablethe cable
Power-over-Ethernet DetectPower-over-Ethernet Detect
Power can run over 2 pairs of wires while data is Power can run over 2 pairs of wires while data is on the remaining 2 pairson the remaining 2 pairs
Power is supplied by a PSE and received by the Power is supplied by a PSE and received by the PD. PD. 42~57 Volts 42~57 Volts
Power-over-Ethernet DetectPower-over-Ethernet Detect
Detection Level can be varied as well as Detection Level can be varied as well as Turn-on and Turn-off voltagesTurn-on and Turn-off voltages
PHY to MAC CommunicationPHY to MAC Communication
PHY LayerPHY Layer Transmission of raw Transmission of raw
bits, not logical databits, not logical data
MAC LayerMAC Layer Logical communicationLogical communication
PHY to MAC CommunicationPHY to MAC Communication
Microcontroller (MCU) Microcontroller (MCU) Able to communicate with PHY layerAble to communicate with PHY layer
Uses Media Independent Interface (MII)Uses Media Independent Interface (MII)
Readable InterfaceReadable Interface
Microcontroller can be programmed to Microcontroller can be programmed to send data tosend data to LCD DisplayLCD Display ComputerComputer LEDsLEDs
PHY to YOUPHY to YOU
ConclusionConclusion
Ethernet History and StructureEthernet History and Structure Time Domain ReflectometryTime Domain Reflectometry Active Link Cable DiagnosticsActive Link Cable Diagnostics Digital Spectrum AnalysisDigital Spectrum Analysis Power-over-Ethernet DetectPower-over-Ethernet Detect Output DataOutput Data
QUESTIONS?QUESTIONS?