EthernetEthernet PetrPetr GrygGrygáárekrek © 2005 Petr Grygarek, Advanced Computer Networks Technologies 1 EthernetEthernet HistorHistoryy •ResearchResearch background:background: AlohaNetAlohaNet •UniversityUniversity ofof Hawai,Hawai, 19701970:: commoncommon (radio)(radio) channelchannel sharingsharing methodsmethods –– basisbasis forfor CSMA/CDCSMA/CD •1980:1980: DIXDIX publishedpublished EthernetEthernet standardstandard (Metcalfe)(Metcalfe) •1985:1985: IEEEIEEE 802802.3.3 (MAC(MAC andand LLCLLC layers)layers) •10Base5,10Base5, 10Base2,10Base2, 10BaseT10BaseT •19951995 IEEEIEEE 802.3u802.3u (Fast(Fast Ethernet)Ethernet) •19981998 IEEEIEEE 802.3z802.3z (Gigabit(Gigabit Ethernet)Ethernet) •20022002 IEEEIEEE 802.3ae802.3ae (10Gb(10Gb Ethernet)Ethernet) •...... © 2005 Petr Grygarek, Advanced Computer Networks Technologies 2 EthernetEthernet NamingNaming RulesRules (IEEE(IEEE Standard)Standard) MbpsMbps [Base|Broad][Base|Broad] [segment[segment_length_length_m_m || -medium-medium]] --TT -- TwistedTwisted Pair,Pair, --FF -- FiberFiber optic,optic, ...... e.g.e.g. 10Base5,10Base5, 10BaseT,10BaseT, 100BaseF100BaseF NameName ofof eacheach particularparticular EthernetEthernet technologytechnology defineddefined inin individualindividual supplementsupplementss ofof 802.3802.3 standardstandard •e.ge.g 802.3u,802.3u, 802.3ab,802.3ab, 802.3z802.3z © 2005 Petr Grygarek, Advanced Computer Networks Technologies 3 Half-duplexHalf-duplex andand Full-duplexFull-duplex EthernetEthernet •HalfHalf duplexduplex –– colissioncolission envirnmentenvirnment (CSMA/CD)(CSMA/CD) •FullFull duplexduplex -- colission-freecolission-free (switched)(switched) environmentenvironment InIn half-duplexhalf-duplex modemode wewe havehave toto adhereadhere CSMA/CSMA/ CDCD timingtiming thatthat impliesimplies thethe maximummaximum cablecable lengthslengths ForFor compatibilitycompatibility withwith half-duplexhalf-duplex NICs,NICs, P2PP2P linkslinks maymay alsoalso operateoperate inin half-duplexhalf-duplex modemode © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 4 HistoricalHistorical EthernetEthernet ImplementationsImplementations © 2005 Petr Grygarek, Advanced Computer Networks Technologies 5 10Base510Base5 == ThickThick EthernetEthernet == DIXDIX EthernetEthernet == ETHERNETETHERNET IIII © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 6 10Base510Base5 CapabilitiesCapabilities •BusBus (coax)(coax) „Yellow„Yellow Cable“Cable“ •50ohm,50ohm, diameterdiameter ofof 1010 mmmm •MaxMax segmentsegment lengthlength 500m,500m, terminatedterminated •MaxMax 55 segmentssegments interconnectedinterconnected byby 44 repeaters,repeaters, stationsstations maymay bebe placedplaced onlyonly onon 33 segmentssegments (5-4-3(5-4-3 rule)rule) •MaxMax 100100 stationsstations perper segment,segment, minimumminimum distancedistance ofof 2.52.5 mm •ManchesterManchester encodingencoding •UtilizesUtilizes externalexternal transceiverstransceivers (AUI(AUI interface)interface) •AttachedAttached toto busbus byby T-connectorT-connector oror wampirewampire taptap © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 7 10Base210Base2 == ThinThin EthernetEthernet == CheaperNetCheaperNet •bus,bus, coaxcoax RG58RG58 •50ohm,50ohm, diameterdiameter ofof 55 mm)mm) •MaxMax segmentsegment lengthlength 185m,185m, terminatedterminated •5-4-35-4-3 rulerule •MaxMax 3030 stationsstations perper segment,segment, minimumminimum distancedistance 0.5m0.5m •Interconnection:Interconnection: BNCBNC andand TT connectorsconnectors •TransceiverTransceiver isis integratedintegrated onon thethe NICNIC © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 8 10BaseT10BaseT •StarStar (tree)(tree) topologytopology •22 twistedtwisted pairspairs (UTP3)(UTP3) ++ RJ-45RJ-45 connectorsconnectors •MayMay operateoperate inin full-duplexfull-duplex modemode whenwhen switchesswitches areare appliedapplied •StationsStations interconnectedinterconnected withwith hubshubs •5-4-(3)5-4-(3) rulerule •mmax.ax. 512512 stationsstations inin thethe wholewhole treetree •MaxMax 100m100m betweenbetween hubhub andand NICNIC •minmin 0.6m0.6m •CrossingCrossing ofof transmittertransmitter andand receiverreceiver cable pairs cable© 2009 Petr Grygárek,pairs FEI VŠB-TU Ostrava, Computer Networks (Bc.) 9 FastFast EthernetEthernet (100Mbps)(100Mbps) •IEEEIEEE 802.3u802.3u •BasedBased onon 10BaseT10BaseT •thethe samesame MACMAC addressaddress protocolprotocol andand frameframe formatformat •NICsNICs areare obviouslyobviously backwardbackward compatiblecompatible withwith 10BaseT10BaseT •SpeedSpeed autonegotiationautonegotiation capabilitycapability •differentdifferent lineline encodingencoding •UsesUses UTP5,UTP5, 100m100m betweenbetween networknetwork devicesdevices © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 10 PhysicalPhysical LayerLayer ofof FastFast EthernetEthernet •100BaseTX:100BaseTX: UTP5,UTP5, STPSTP –– UTP5,UTP5, maxmax 100m,100m, 4B5B4B5B ++ MLT3,MLT3, 125125 MHzMHz •100BaseFX:100BaseFX: FO,FO, max.max. distancedistance NIC-NIC- hubhub isis 200m200m (because(because ofof CSMA/CD)CSMA/CD) •OtherOther sparselysparsely usedused optionsoptions •DevelopedDeveloped forfor compatibilitycompatibility withwith olderolder cablingscablings -- 100BaseT2,100BaseT2, 100BaseT4100BaseT4 © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 11 FastFast EthernetEthernet TopologiesTopologies (half-duplex)(half-duplex) •22 directlydirectly connectedconnected NICsNICs •StarStar withwith ClassClass II hubhub •TwoTwo ClassClass IIII hubshubs interconnectedinterconnected byby lineline ofof maximummaximum 1010 mm inin lengthlength HubHub classclass II andand IIII differdiffer inin •MaximumMaximum allowedallowed signalsignal delaydelay •CapabilityCapability ofof encodingencoding transformation,transformation, i.e.i.e. thethe abilityability ofof usingusing differentdifferent mediamedia inin aa singlesingle collisioncollision domaindomain •e.g. transformaiton of 100BaseTX to 100BaseT4 © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 12 EthernetEthernet TodayToday •EthernetEthernet todaytoday isis aa wholewhole familyfamily ofof networkingnetworking technologiestechnologies (100Mbps+)(100Mbps+) •LAN,LAN, MAN,MAN, WANWAN •CompatibilityCompatibility stillstill maintainedmaintained © 2005 Petr Grygarek, Advanced Computer Networks Technologies 13 GigabitGigabit EthernetEthernet (802.3z)(802.3z) •DevelopedDeveloped sincesince 1995,1995, originallyoriginally supposedsupposed toto requirerequire fiberfiber opticoptic oror coaxcoax cable,cable, standardstandard laterlater extendedextended forfor twistedtwisted pairpair •802.3ab802.3ab –– compatiblecompatible withwith existingexisting wiringswirings (Cat5e)(Cat5e) •MakesMakes thethe standardstandard EthernetEthernet fasterfaster againagain • CSMACSMA oror switching,switching, IEEEIEEE 802.3802.3 frame,frame, simplesimple starstar topologytopology •ProblemsProblems withwith minimumminimum frameframe lengthlength inin collision-modecollision-mode whenwhen tryingtrying toto keepkeep thethe samesame maximummaximum cablecable lengthslengths asas withwith 10BaseT10BaseT •AppendsAppends aa paddingpadding toto 512B512B intointo aa frameframe ifif necessarynecessary oror appliesapplies packetpacket bursting.bursting. • MostMost commonlycommonly usedused forfor backbonebackbone linkslinks © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 14 PhysicalPhysical LayerLayer ofof thethe GigabitGigabit EthernetEthernet • 1000Base-T:1000Base-T: UTP5eUTP5e • All 4 pairs used simultaneously in both directions (PAM5, echo cancellation), max. 100m • Problems with reflections connectors (the cabling system may start to resonate) • 1000Base-SX1000Base-SX (short(short wavelength-850wavelength-850 nm)nm) –– usedused moremore oftenoften • 8B10B encoding • 62.5 um MMF 440m, 50 um MMF 550m • 1000Base-LX1000Base-LX (long(long wavelength-1300wavelength-1300 nm)nm) • 8B10B encoding • SMF 3 km, 62.5 um MMF 440m, 50 um MMF 550m. • Usage of „offsets“ to limit transversal modes on MMF (decreases dispersion) • ANSIANSI FibreFibre ChannelChannel • Supports bandwidths of 133Mpbs to 1Gbps on various cable types (MMF, STP, coax) © 2009 Petr Grygárek, FEI VŠB-TU Ostrava, Computer Networks (Bc.) 15 1000BaseX1000BaseX ((802.3z802.3z)):: FiberFiber OpticsOptics •extendsextends thethe originaloriginal LANLAN technologytechnology toto distancesdistances thatthat makemake EthernetEthernet aa WAN/MANWAN/MAN standardstandard •1000BASE-1000BASE-SXSX •850nm850nm laser/LEDlaser/LED,, MMMM fiber,fiber, SCSC –– lowlow costcost •distancesdistances 220-550m220-550m ((betterbetter forfor 50/12550/125 thanthan 62.5/5062.5/50 fiberfiber)) •1000BASE-1000BASE- LXLX •1310nm1310nm laserlaser SMSM fiberfiber (5km)(5km) oror MMMM fiberfiber (500m)(500m),, SCSC •8B10B+NRZ8B10B+NRZ ("level-driven")("level-driven") encodingencoding •SomeSome bitbit combinationcombination havehave alternativealternative 8B10B8B10B codewordscodewords •chosen dynamically to reach balanced bit pattern •BecauseBecause ofof highhigh rate,rate,11ss andand 00ss encodedencoded withwith lowlow andand highhigh powerpower insteadinstead ofof presence/absencepresence/absence ofof lightlight © 2005 Petr Grygarek, Advanced Computer Networks Technologies 16 1000BaseT1000BaseT (802.3ab)(802.3ab) • usesuses TPTP CategoryCategory 5e5e oror higherhigher • cat5e allows 125Mbps • allall fourfour pairs,pairs, 125125 MbdMbd eacheach • 4D-PAM54D-PAM5 lineline encodingencoding • pulse amplitude modulation, 5