Local Area Network: Ethernet and Advanced Bridging

Transcription

1 Local rea Network: Ethernet and dvanced Bridging id=56 for discussion and exercises Laurent Toutain ugust 27, 20 Table of Contents Introduction 2 Network Classification By scope By ccess method By topology 3 IEEE Model Introduction rchitecture ddresses Interconnection IEEE groups overview 4 loha 5 Ethernet Introduction IEEE at 0 Mbit/s 00 Mbit/s CSM/CD Switching uto-configuration Frame Format 6 IEEE 802. Physical Layer CSM/C rchitecture and Frames 7 LLC Layer Introduction Frame Format SNP 8 Spanning Tree Bridge loops lgorithm Rapid STP 9 VLN Introduction IEEE 802.p/Q 0 Metropolitan Networks QinQ Mac In Mac Slide 2 Laurent Toutain RES 30

2 Introduction Introduction ISO Reference Model pplication Presentation Session 6 Transport Network Data Link Physical Slide 4 Laurent Toutain RES 30

3 Introduction ISO Reference Model pplication 3 radio 5 optical copper Presentation Session copper copper radio 6 8 Transport copper radio radio Network Data Link optical optical 4 optical radio 7 Physical 2 Slide 4 Laurent Toutain RES 30 Introduction ISO Reference Model pplication Presentation Session Transport Network Data Link Physical copper optical radio copper optical radio optical 0000 copper optical copper radio radio radio Slide 4 Laurent Toutain RES 30

4 Introduction ISO Reference Model pplication Presentation Session Transport Network Data Link Physical copper optical radio copper optical radio optical 0000 copper optical 6 radio radio copper radio Slide 4 Laurent Toutain RES 30 Introduction ISO Reference Model pplication Presentation Session Transport Network Data Link Physical copper optical radio optical copper 0 4 radio optical copper optical 6 radio radio copper - Transform Binary signal into Physical signal - Clock Synchronization radio Slide 4 Laurent Toutain RES 30

5 Introduction ISO Reference Model pplication Presentation Session Transport Network Data Link Physical Slide 4 Laurent Toutain RES 30 Introduction ISO Reference Model pplication Presentation Session Transport Network Data Link Physical RQ RQ RQ FEC FEC 0 4 Hybrid FEC FEC 6 RQ Hybrid FEC RQ Slide 4 Laurent Toutain RES 30

6 Introduction ISO Reference Model pplication Presentation Session Transport Network Data Link Physical RQ RQ RQ FEC FEC 0 - Build PDU - Correct Error - No need for addresses since point-to-point links 6 4 Hybrid FEC FEC RQ Hybrid FEC RQ Slide 4 Laurent Toutain RES 30 Introduction ISO Reference Model pplication Presentation Session 6 Transport Network Data Link Physical Slide 4 Laurent Toutain RES 30

7 Introduction ISO Reference Model pplication Presentation Session copy PDU from link to link until destination - ddresses are needed to identify equipments 6 8 Transport Network Data Link 4 7 Physical 2 Slide 4 Laurent Toutain RES 30 Introduction ISO Reference Model pplication Presentation Session 3 Correct 5 errors introduced by Network: - Reordering - Packet losses recovery - Congestions 6 control 8 Transport Network Data Link 4 7 Physical 2 Slide 4 Laurent Toutain RES 30

8 Introduction ISO Reference Model pplication Presentation 3 pplications protocol (database, file 5 transfert, remote login, web...) Negociate common format representation between both ends 8 Session Transport 6 In connection oriented network, may be used to re-establish connections and restart transfer from synchronization points Network Data Link 4 7 Physical 2 Slide 4 Laurent Toutain RES 30 Introduction ISO Reference Model: Limits pplication 3 5 point to point Presentation 8 Session Transport Network Data Link Point to Point link. Bidirectional link: data can be sent anytime. No need for addresses Physical 2 Slide 5 Laurent Toutain RES 30

9 Introduction ISO Reference Model: Limits pplication Presentation old Ethernet, PLC Session Transport Wi-Fi, Sensor Network Network Data Link Physical Slide 5 Laurent Toutain RES 30 Introduction ISO Reference Model: Limits pplication Presentation Shared Media: - Need addresses Session to identify source and destination - Need rules to allow only one host to send at a specific time. Transport old Ethernet, PLC Wi-Fi, Sensor Network Network Data Link Physical Slide 5 Laurent Toutain RES 30

10 Introduction ISO Reference Model: Limits pplication Presentation old Ethernet, PLC Session Transport Wi-Fi, Sensor Network Network Data Link Physical Must be redefined (address, media access control Must be adapted to new media Slide 5 Laurent Toutain RES 30 Introduction Main characteristics Transmission support (media) shared by several equipments: Operating mode: broadcast + Media ccess Control When an equipment send data, all others may receive it equipment should not send data when another one is sending. Possible conflict void centralized transmission right management shared media imposes: way to identity unambiguously any equipments, Decentralized transmission right management No configuration from the user Scalability limitations due to broadcast media IEEE defines a model for those kind of networks (layer and 2 of OSI Reference Model) Slide 6 Laurent Toutain RES 30

11 Network Classification By scope By scope Network Classification By scope Scope # equipments LN ccess Metropolitan WN hist: m to 2 km hist: 00 Mbit/s No limit m to 00 m up to 0 km hist: 2 to km No limit Owner Cost Throughput 2 to 50 2 to 00 2 to 00 User provider : direct facturation provider (indirect facturation) No charge f(throughput) Subscription (SL: Service Level greement) hist: 4 to 0 Mbit/s Provider (indirect facturation) Distance, Duration, Subscription (SL) 50 bit/s to 2 Mbit/s Error rate Delay Technologies 00 Mbit/s to Gbit/s 2 to 20 Mbit/s 0Gbit/s Multiple of 2.5 Gbit/s < 0 9 < 0 6 < to 00µ 0 to 5 ms Mostly propagation delays Ethernet - Wi-Fi DSL (TM Ethernet) WiMX (Ethernet) 3G Ethernet SDH/WDM, Ethernet Slide 8 Laurent Toutain RES 30

12 By scope Network Classification By scope Scope # equipments LN ccess Metropolitan WN hist: m to 2 km hist: 00 Mbit/s No limit m to 00 m up to 0 km hist: 2 to km No limit Owner Cost Throughput 2 to 50 2 to 00 2 to 00 User provider : direct facturation provider (indirect facturation) No charge f(throughput) Subscription (SL: Service Level greement) hist: 4 to 0 Mbit/s Provider (indirect facturation) Distance, Duration, Subscription (SL) 50 bit/s to 2 Mbit/s Error rate Delay Technologies 00 Mbit/s to Gbit/s 2 to 20 Mbit/s 0Gbit/s Multiple of 2.5 Gbit/s < 0 9 < 0 6 < to 00µ 0 to 5 ms Mostly propagation delays Ethernet - Wi-Fi DSL (TM Ethernet) WiMX (Ethernet) 3G Ethernet SDH/WDM, Ethernet Slide 8 Laurent Toutain RES 30 By scope Network Classification By scope Scope # equipments LN ccess Metropolitan WN hist: m to 2 km hist: 00 Mbit/s No limit m to 00 m up to 0 km hist: 2 to km No limit Owner Cost Throughput 2 to 50 2 to 00 2 to 00 User provider : direct facturation provider (indirect facturation) No charge f(throughput) Subscription (SL: Service Level greement) hist: 4 to 0 Mbit/s Provider (indirect facturation) Distance, Duration, Subscription (SL) 50 bit/s to 2 Mbit/s Error rate Delay Technologies 00 Mbit/s to Gbit/s 2 to 20 Mbit/s 0Gbit/s Multiple of 2.5 Gbit/s < 0 9 < 0 6 < to 00µ 0 to 5 ms Mostly propagation delays Ethernet - Wi-Fi DSL (TM Ethernet) WiMX (Ethernet) 3G Ethernet SDH/WDM, Ethernet Slide 8 Laurent Toutain RES 30

13 By scope Network Classification By scope Scope # equipments LN ccess Metropolitan WN hist: m to 2 km hist: 00 Mbit/s No limit m to 00 m up to 0 km hist: 2 to km No limit Owner Cost Throughput 2 to 50 2 to 00 2 to 00 User provider : direct facturation provider (indirect facturation) No charge f(throughput) Subscription (SL: Service Level greement) hist: 4 to 0 Mbit/s Provider (indirect facturation) Distance, Duration, Subscription (SL) 50 bit/s to 2 Mbit/s Error rate Delay Technologies 00 Mbit/s to Gbit/s 2 to 20 Mbit/s 0Gbit/s Multiple of 2.5 Gbit/s < 0 9 < 0 6 < to 00µ 0 to 5 ms Mostly propagation delays Ethernet - Wi-Fi DSL (TM Ethernet) WiMX (Ethernet) 3G Ethernet SDH/WDM, Ethernet Slide 8 Laurent Toutain RES 30 Questions Network Classification By scope Where was historically located the bottleneck? and currently? LN ccess Metro WN Will Future WN technologies will reduce delays? Yes No Slide 9 Laurent Toutain RES 30

14 Questions Network Classification By scope Where was historically located the bottleneck? and currently? LN Curr. ccess Metro Hist. WN Will Future WN technologies will reduce delays? Yes No Slide 0 Laurent Toutain RES 30 Questions Network Classification By scope Where was historically located the bottleneck? and currently? LN Curr. ccess Metro Hist. WN Will Future WN technologies will reduce delays? Yes X No Slide 0 Laurent Toutain RES 30

15 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms Slide Laurent Toutain RES 30 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms Slide 2 Laurent Toutain RES 30

16 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms LN Slide 2 Laurent Toutain RES 30 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms LN WN Slide 2 Laurent Toutain RES 30

17 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms LN WN Slide 2 Laurent Toutain RES 30 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms LN WN WN Slide 2 Laurent Toutain RES 30

18 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms LN WN WN Europe Slide 2 Laurent Toutain RES 30 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms WN LN WN WN WN Europe U.S. Slide 2 Laurent Toutain RES 30

19 Categories of network Network Classification By scope This listing gives the name of interconnection equipments and the time (in ms) to reach a web site in Korea. From this information, associate a possible categories of network to each equipment: mgs-c5.ipv6.rennes.enst-bretagne.fr 0 ms 2 << unknown >> 3 te4--caen-rtr-02.noc.renater.fr 7 ms 4 te4--rouen-rtr-02.noc.renater.fr 7 ms 5 te paris-rtr-00.noc.renater.fr 7 ms 6 renater.rt.par.fr.geant2.net 7 ms 7 so rt.lon.uk.geant2.net 4 ms 8 so rt.ams.nl.geant2.net 22 ms 9 xe rtr.newy32aoa.net.internet2.edu 06 ms 0 ge rtr.chic.net.internet2.edu 33 ms kreonet2-abilene.kreonet.net 88 ms ms 3 supersiren.kreonet.net 302 ms 4 kaist-gw.kaist.ac.kr 295 ms ms ms ms 8 iccweb.kaist.ac.kr 296 ms WN LN WN WN WN WN LN Europe U.S. sia Slide 2 Laurent Toutain RES 30 Network Classification By ccess method

20 By ccess method Network Classification By ccess method Broadcast: Ethernet, Wi-Fi, PLC, Sensor Networks Non Broadcast Multiple ccess: ny equipment can be joined, but only once at a specific time Telephony Network, TM. Point-to-Point: Leased Line, Virtual Circuit once established Master/Slave: communication only possible between the master and a slave (no direct communication between slaves) ISDN, GSM (communication between the mobile phone and the relay) Slide 4 Laurent Toutain RES 30 Questions Network Classification By ccess method Which technologies require addresses (and how many)? Broadcast NBM point-to-point Master/Slave Which of these technologies are scalable? Broadcast NBM point-to-point Master/Slave Slide 5 Laurent Toutain RES 30

21 Questions Network Classification By ccess method Which technologies require addresses (and how many)? Unique 2 Broadcast Hierarchical 2 NBM 0 point-to-point Master/Slave Which of these technologies are scalable? Broadcast NBM point-to-point Master/Slave Slide 6 Laurent Toutain RES 30 Network Classification By topology

22 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular irregular Wireless wired simple ring Full Mesh Meshed d Hoc double ring Star d Hoc Routed Slide 8 Laurent Toutain RES 30 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular irregular Old Technologies Wireless wired simple ring double ring Full Mesh Meshed Current Tech. d Hoc Star d Hoc Routed Slide 8 Laurent Toutain RES 30

23 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular ctive Equipment: Hub, Switch irregular Old Technologies wired Wireless simple ring double ring Full Mesh Meshed Current Tech. d Hoc Star d Hoc Routed Slide 8 Laurent Toutain RES 30 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular irregular Wireless wired d Hoc simple ring Full Mesh Meshed d Hoc double ring Star Infrastructure. d Hoc Routed Slide 8 Laurent Toutain RES 30

24 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular irregular Wireless wired ccess Point (P) d Hoc simple ring Full Mesh Meshed d Hoc double ring Star Infrastructure. d Hoc Routed Slide 8 Laurent Toutain RES 30 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular irregular Power Lines Wireless wired simple ring Full Mesh Meshed d Hoc double ring Star d Hoc Routed Slide 8 Laurent Toutain RES 30

25 Network rchitecture Network Classification By topology Network rchitecture Point-to-Point Broadcast Regular irregular Wireless wired simple ring Full Mesh Meshed d Hoc double ring Star d Hoc Routed Slide 8 Laurent Toutain RES 30 IEEE Model Introduction

26 IEEE Model IEEE Model Introduction Effort started in February 980 (802) to specify LN protocols Currently covers also all others technologies (ccess, Metro and some part of WN) dapt ISO Reference Model to broadcast media. No centralized equipment (i.e. Master/Slave): ny host can leave or enter the network at any time. USB is not a LN technology, since a master is needed. Not a single solution: No universal solution (depending on the media) Wired and wireless media react differently Industrial may push different technologies Competition exists between IEEE 802 solutions Market will decide But a current architecture to ease interconnection. Universal Serial Bus Slide 20 Laurent Toutain RES 30 IEEE groups IEEE Model Introduction Standardization is a dynamic process: Some technologies disappear due to la lack of interest from the market Some technologies appear: New areas (wireless, Wireless Sensor Network, Personal rea Network,... ) ll technologies must evolve Increment speed Use new media New usages (energy aware,...) IEEE 802 is divided into subgroups. Each Working Group is designated by a number 2. For instance IEEE802.3 does standardization for Ethernet 2 See; Slide 2 Laurent Toutain RES 30

27 IEEE groups IEEE Model Introduction Each Working Group issues regularly a new version of the standard: IEEE , IEEE , IEEE Std , Subworking group are working on make evolve some specific part of the standard: They are designated by a letter. Capital letter: a new document Small letter: a modification to an existing document. These results are merged in the next issue of the full standard Sometime the letter continues to be used to refer to the technology: IEEE 802.Q: Virtual LNs IEEE 802.g: Wi-Fi at 54 Mbit/s... Standards and approved extensions to standards are available on IEEE Explorer: Slide 22 Laurent Toutain RES 30 IEEE Model rchitecture

28 IEEE rchitecture IEEE Model rchitecture ISO 2 IEEE 802 scope Slide 24 Laurent Toutain RES 30 IEEE rchitecture IEEE Model rchitecture ISO 2 IEEE 802.: ddressing, Interconnection, Virtualization IEEE 802 scope Slide 24 Laurent Toutain RES 30

29 IEEE rchitecture IEEE Model rchitecture ISO 2 IEEE 802.: ddressing, Interconnection, Virtualization IEEE 802 scope IEEE 802.2: LLC Logical Link Control Slide 24 Laurent Toutain RES 30 IEEE rchitecture IEEE Model rchitecture ISO 2 IEEE 802.: ddressing, Interconnection, Virtualization IEEE 802 scope IEEE 802.2: LLC Logical Link Control IEEE 802.x: MC Medium ccess Control IEEE IEEE IEEE IEEE IEEE IEEE 802. IEEE IEEE IEEE IEEE IEEE IEEE IEEE IEEE IEEE Slide 24 Laurent Toutain RES 30

30 IEEE rchitecture IEEE Model rchitecture ISO Inactive LLC may be skipped with some versions of Ethernet) 2 IEEE 802.: ddressing, Interconnection, Virtualization IEEE 802 scope IEEE 802.2: LLC Logical Link Control IEEE 802.x: MC Medium ccess Control IEEE IEEE////////// IEEE///////// IEEE///////// IEEE////////// IEEE 802. IEEE/////////// IEEE/////////// IEEE IEEE IEEE IEEE IEEE IEEE IEEE Slide 24 Laurent Toutain RES 30 IEEE Model ddresses

31 IEEE 802 ddresses IEEE Model ddresses ddresses need to be unique on the link, ddresses must be assigned without any centralized server, ddresses are assigned by the manufacturer: Network card or Equipment manufacturer, They are globaly (worldwide) unique ddresses can be changed by the network manager (do not base security on them). IEEE defines three length: MC-6: 6 bit long, used on network where frame size is important (e.g. Wireless Sensor Networks) MC-48: 48 bit long, mainly used in LN technologies (Ethernet, Wi-Fi) no exhaustion before 200. MC-64: 64 bit long, not actually used. IEEE makes the difference between MC and EUI (Extended Unique Identifier): used to identify a equipment (not used to send frames) EUI-48 or EUI-64. Slide 26 Laurent Toutain RES 30 How to make addresses globally unique? IEEE Model ddresses OUI Slide 27 Laurent Toutain RES 30

32 How to make addresses globally unique? IEEE Model ddresses Organizational Unit Identifier: llocated ($450) by IEEE OUI Slide 27 Laurent Toutain RES 30 How to make addresses globally unique? IEEE Model ddresses MC EUI 48 OUI Vendor ID Slide 27 Laurent Toutain RES 30

33 How to make addresses globally unique? IEEE Model ddresses MC EUI 48 OUI Vendor ID Guaranty unique by the vendor Slide 27 Laurent Toutain RES 30 How to make addresses globally unique? IEEE Model ddresses MC EUI 48 I / G OUI Vendor ID I=0: Individual G=: Group Slide 27 Laurent Toutain RES 30

34 How to make addresses globally unique? IEEE Model ddresses MC EUI 48 I / G U / L OUI U=0: Universal L=: Local I=0: Individual G=: Group Vendor ID Slide 27 Laurent Toutain RES 30 How to make addresses globally unique? IEEE Model ddresses MC EUI 48 I / G U / L OUI U=0: Universal L=: Local I=0: Individual G=: Group Vendor ID MC EUI 64 I / G U / L OUI Vendor ID Slide 27 Laurent Toutain RES 30

35 How to make addresses globally unique? IEEE Model ddresses MC EUI 48 I / G U / L OUI U=0: Universal L=: Local I=0: Individual G=: Group Vendor ID MC EUI 64 I / G U / L OUI Vendor ID MC 6 I / G Local Slide 27 Laurent Toutain RES 30 Different ddresses I IEEE Model ddresses Representation: Bytes separated by dashes (sometime by column) Ex: df-a9-f7-ac Unicast ddresses: I/G bit = 0 The frame is sent to only one host on the link OUI is allocated by IEEE; See to find some values. Who is the vendor of df-a9-f7-ac Broadcast ddress Sent to all the hosts connected to the link. ll bits equal to ff-ff-ff-ff-ff-ff Slide 28 Laurent Toutain RES 30

36 Different ddresses I IEEE Model ddresses Representation: Bytes separated by dashes (sometime by column) Ex: df-a9-f7-ac Unicast ddresses: I/G bit = 0 The frame is sent to only one host on the link OUI is allocated by IEEE; See to find some values. Who is the vendor of df-a9-f7-ac pple Inc. Broadcast ddress Sent to all the hosts connected to the link. ll bits equal to ff-ff-ff-ff-ff-ff Slide 28 Laurent Toutain RES 30 Different ddresses II IEEE Model ddresses Multicast ddress: bit I/G = and address is different from Broadcast address. Nodes must subscribe to this address to receive data. No need to subscribe to send. Warning: First bit send is the I/G bit Inform interconnection elements (bridges) to copy the frame on other media. In numerical representation, this bit is on the right. OUI Vendor ID Slide 29 Laurent Toutain RES 30

37 Different ddresses II IEEE Model ddresses Multicast ddress: bit I/G = and address is different from Broadcast address. Nodes must subscribe to this address to receive data. No need to subscribe to send. Warning: First bit send is the I/G bit Inform interconnection elements (bridges) to copy the frame on other media. In numerical representation, this bit is on the right. OUI Vendor ID 0 Slide 29 Laurent Toutain RES 30 Different ddresses II IEEE Model ddresses Multicast ddress: bit I/G = and address is different from Broadcast address. Nodes must subscribe to this address to receive data. No need to subscribe to send. Warning: First bit send is the I/G bit Inform interconnection elements (bridges) to copy the frame on other media. In numerical representation, this bit is on the right. OUI Vendor ID 0 Slide 29 Laurent Toutain RES 30

38 ddresses Management: Computer rchitecture IEEE Model ddresses Slide 30 Laurent Toutain RES 30 ddresses Management: Computer rchitecture IEEE Model ddresses Computer Bus Network Card Slide 30 Laurent Toutain RES 30

39 ddresses Management: Computer rchitecture IEEE Model ddresses drivers hardware 2 Slide 30 Laurent Toutain RES 30 ddresses Management: Computer rchitecture IEEE Model ddresses drivers hardware 2 Physical Layer: Information Coding/Decoding Slide 30 Laurent Toutain RES 30

40 ddresses Management: Computer rchitecture IEEE Model ddresses drivers hardware 2 DL Layer: MC, address check, CRC Physical Layer: Information Coding/Decoding Slide 30 Laurent Toutain RES 30 ddresses Management: Computer rchitecture IEEE Model @3 2 DL Layer: Framing (except CRC) DL Layer: MC, address check, CRC Physical Layer: Information Coding/Decoding Slide 30 Laurent Toutain RES 30

41 ddresses Management: Unicast IEEE Model @4 ) MC Layer receives data.request Slide 30 Laurent Toutain RES 30 ddresses Management: Unicast IEEE @3 ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) Slide 30 Laurent Toutain RES 30

42 ddresses Management: Unicast IEEE ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card Slide 30 Laurent Toutain RES 30 ddresses Management: Unicast IEEE ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire Slide 30 Laurent Toutain RES 30

43 ddresses Management: Unicast IEEE ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire 5) recognizes its address and sends it to upper layer. Others discard the card and the frame is not seen by equipments. Slide 30 Laurent Toutain RES 30 ddresses Management: Unicast IEEE ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire 5) recognizes its address and sends it to upper layer. Others discard the card and the frame is not seen by equipments. Slide 30 Laurent Toutain RES 30

44 ddresses Management: Broadcast IEEE Model @M ) MC Layer receives data.request for FF 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire Slide 30 Laurent Toutain RES 30 ddresses Management: Broadcast IEEE Model @M ) MC Layer receives data.request for FF 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire 5) ll equipments recognize the broadcast address and transmit the information to the upper layer. Slide 30 Laurent Toutain RES 30

45 ddresses Management: Multicast IEEE Model @4 0) Equipments register the multicast address ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire Slide 30 Laurent Toutain RES 30 ddresses Management: Multicast IEEE Model @4 0) Equipments register the multicast address ) MC Layer receives data.request 2) MC Layer reads source MC address (can be overloaded) 3) MC Layer creates the frame and sends it to the Network card 4) MC Layer computes the CRC and perform the MC protocol and sends the frame on the wire 5) Equipment which have registered the multicast address receive the information.. Slide 30 Laurent Toutain RES 30

46 ddresses Management: Promiscuous IEEE sets promiscuous mode (some privileges are needed) Slide 30 Laurent Toutain RES 30 ddresses Management: Promiscuous IEEE Model sets promiscuous mode (some privileges are needed) sends a frame Slide 30 Laurent Toutain RES 30

47 ddresses Management: Promiscuous IEEE Model sets promiscuous mode (some privileges are needed) sends a frame accepts the frame (its accepts the frame discards the frame Slide 30 Laurent Toutain RES 30 ddresses Management: Promiscuous IEEE Model sets promiscuous mode (some privileges are needed) sends a frame accepts the frame (its accepts the frame discards the frame Promiscuous is used either to analyze traffic (see wireshark, tcpdump) or by L2 interconnection elements such as bridges Slide 30 Laurent Toutain RES 30

48 Questions IEEE Model ddresses - Multicast is possible with MC-6? - Local addresses can be set with bit U/L=0 F T - FF is a broadcast address - It is possible to forge the MC address of another equipment - IPv6 uses MC addresses such as FF-3-67-, What is the nature of this address? Slide 3 Laurent Toutain RES 30 Questions IEEE Model ddresses - Multicast is possible with MC-6? - Local addresses can be set with bit U/L=0 F T - FF is a broadcast address - It is possible to forge the MC address of another equipment - IPv6 uses MC addresses such as FF-3-67-, What is the nature of this address? Slide 32 Laurent Toutain RES 30

49 Questions IEEE Model ddresses - Multicast is possible with MC-6? - Local addresses can be set with bit U/L=0 F T - FF is a broadcast address - It is possible to forge the MC address of another equipment - IPv6 uses MC addresses such as FF-3-67-, What is the nature of this address? Slide 32 Laurent Toutain RES 30 Questions IEEE Model ddresses - Multicast is possible with MC-6? - Local addresses can be set with bit U/L=0 F T - FF is a broadcast address - It is possible to forge the MC address of another equipment - IPv6 uses MC addresses such as FF-3-67-, What is the nature of this address? Slide 32 Laurent Toutain RES 30

50 Questions IEEE Model ddresses - Multicast is possible with MC-6? - Local addresses can be set with bit U/L=0 F T - FF is a broadcast address - It is possible to forge the MC address of another equipment - IPv6 uses MC addresses such as FF-3-67-, What is the nature of this address? Slide 32 Laurent Toutain RES 30 Questions IEEE Model ddresses - Multicast is possible with MC-6? - Local addresses can be set with bit U/L=0 F T - FF is a broadcast address - It is possible to forge the MC address of another equipment - IPv6 uses MC addresses such as FF-3-67-, What is the nature of this address? Multicast Slide 32 Laurent Toutain RES 30

51 IEEE Model Interconnection Interconnection IEEE Model Interconnection IEEE 802. group defines interconnection method. Interconnection can occur at different level in the OSI Reference Model Layer : Repeater Layer 2: Bridge Layer 3: Router Layer 7: Gateway, Proxy, LG (pplication Level Gateway) Some old documentation uses Gateway for Router IEEE works on Repeaters... at bit level... and Bridges In store and forward mode; store frames, analyze them and forward on appropriate interface, Bridges learns addresses location reading the frame source field No configuration is needed Slide 34 Laurent Toutain RES 30

52 Repeater IEEE Model Interconnection Different functions: Regenerate signals r Change media optical fiber r twisted pair Propagation delay inside the repeater can be longer than equivalent cable length: time to detect binary values and generate a new signal. lmost invisible to upper layers Slide 35 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D Bridge E F G H Slide 36 Laurent Toutain RES 30

53 Bridge IEEE Model Interconnection B C D Ignore equipment location Bridge E F G H Slide 36 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D C Bridge E F G H Slide 36 Laurent Toutain RES 30

54 Bridge IEEE Model Interconnection B C D C Promiscuous mode Bridge E F G H Slide 36 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D C Bridge nalyzes frame Locates Ignores C location send on all other interfaces E F G H Slide 36 Laurent Toutain RES 30

55 Bridge IEEE Model Interconnection B C D C Bridge E F G H Slide 36 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D C Bridge E F G H Slide 36 Laurent Toutain RES 30

56 Bridge IEEE Model Interconnection B C D Bridge C Locates C E F G H Slide 36 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D C C Bridge E F G H Slide 36 Laurent Toutain RES 30

57 Bridge IEEE Model Interconnection B C D C C Bridge Dest. is on the same link no copy on other interfaces E F G H Slide 36 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D C Bridge F E F G H Slide 36 Laurent Toutain RES 30

58 Bridge IEEE Model Interconnection B C D C Bridge Locates F F F E F G H Slide 36 Laurent Toutain RES 30 Bridge IEEE Model Interconnection B C D C Bridge Dest. is located on the F F other link copy on equipment s link E F G H Slide 36 Laurent Toutain RES 30

59 dvantage IEEE Model Interconnection Bridges learns equipments location Copy frame on other interface only when needed improve security: cannot listen traffic between two equipments located on another link decrease traffic on a link. Can work with different L2 technologies: ddressing rules must be the same: e.g. MC-48 ll fields must be easily filled: No configuration, No queries on the link. For instance: Wi-Fi and Ethernet Bridge is called an ccess Point No scalability ll equipments addresses must be memorized Broadcast/Multicast is sent everywhere Slide 37 Laurent Toutain RES 30 Questions IEEE Model Interconnection What does a bridge when it receives a Broadcast frame? Discard frame Copy frame on all other interfaces bridge may change the frame format bridge does not work if interfaces speed is different bridge is limited to two interfaces It is possible to put more than one bridge on a network F T Slide 38 Laurent Toutain RES 30

60 Questions IEEE Model Interconnection What does a bridge when it receives a Broadcast frame? Discard frame Copy frame on all other interfaces bridge may change the frame format bridge does not work if interfaces speed is different bridge is limited to two interfaces It is possible to put more than one bridge on a network F T Slide 39 Laurent Toutain RES 30 Questions IEEE Model Interconnection What does a bridge when it receives a Broadcast frame? Discard frame Copy frame on all other interfaces bridge may change the frame format bridge does not work if interfaces speed is different bridge is limited to two interfaces It is possible to put more than one bridge on a network F T Slide 39 Laurent Toutain RES 30

61 Questions IEEE Model Interconnection What does a bridge when it receives a Broadcast frame? Discard frame Copy frame on all other interfaces bridge may change the frame format bridge does not work if interfaces speed is different bridge is limited to two interfaces It is possible to put more than one bridge on a network F T Slide 39 Laurent Toutain RES 30 Questions IEEE Model Interconnection What does a bridge when it receives a Broadcast frame? Discard frame Copy frame on all other interfaces bridge may change the frame format bridge does not work if interfaces speed is different bridge is limited to two interfaces It is possible to put more than one bridge on a network F T Slide 39 Laurent Toutain RES 30

62 Questions IEEE Model Interconnection What does a bridge when it receives a Broadcast frame? Discard frame Copy frame on all other interfaces bridge may change the frame format bridge does not work if interfaces speed is different bridge is limited to two interfaces It is possible to put more than one bridge on a network F T Slide 39 Laurent Toutain RES 30 Routers IEEE Model Interconnection Work at L3 (packet) level: IP Layer ddresses follow a logic (generally hierarchical) common part of the address (prefix) is used to locate equipments Routers uses this property for scalability Routers have to be configured Manually and through routing protocols Bridges and routers have almost the same behavior, they can be implemented in the same equipment Bridge some protocols, router the others Bridge some parts of the network, route traffic between these parts Slide 40 Laurent Toutain RES 30

63 Gateways IEEE Model Interconnection Work at application level Depend of the application From a L7 application to another i.e. change Telephony Signalization (SIP to H.323) pplication can be the same on both side: Security: filtering (proxy) Only known and well formed application protocols are authorized. Performances (cache) Some information are stored locally to reduce traffic (P2P, HTTP,... ) Transition from IPv4 to IPv6 (LG: pplication Level Gateway) Same application, but different L3 protocols lso used from a private Internet to the public Internet Not all L7 protocols can use gateways Slide 4 Laurent Toutain RES 30 IEEE Model IEEE groups overview

64 IEEE groups overview IEEE Model IEEE groups overview IEEE 802.: rchitecture, ddresses, Interconnection, Virtualization IEEE 802.2: Equivalent of Link Layer (see later) IEEE 802.3: Ethernet Physical Layer (see later) from 0 Mbit/s to 00Gbit/s support: Coaxial (obsolete), twisted pair, optical fiber MC lgorithm: From shared media with CSM/CD (Carrier Sense Multiple ccess/collision Detect) to switched (brigded) full duplex links Compatible Frame Format since first proposals Slide 43 Laurent Toutain RES 30 IEEE 802.4; Token Bus IEEE Model IEEE groups overview Bus: Coaxial cable where all equipments are connected Broadband: only a range of frequencies where allocated to token bus Token: Right to talk, must circulate among equipments more deterministic than CSM/CD each equipment can keep the token for a maximum time can easily compute maximum waiting time better performances than CSM/CD when the network is loaded, worse performances when the network is not loaded. Slide 44 Laurent Toutain RES 30

65 Token Management IEEE Model IEEE groups overview B C D C x: messages How to manage token circulation on a bus? What his the next equipment? How new equipments can enter into the network? What append if the token disappear? Expensive technology, reserved to factories: broadband, token management, less production Slide 45 Laurent Toutain RES 30 Token Management IEEE Model IEEE groups overview B C D C :token How to manage token circulation on a bus? What his the next equipment? How new equipments can enter into the network? What append if the token disappear? Expensive technology, reserved to factories: broadband, token management, less production Slide 45 Laurent Toutain RES 30

66 Token Management IEEE Model IEEE groups overview B C D How to manage token circulation on a bus? What his the next equipment? How new equipments can enter into the network? What append if the token disappear? Expensive technology, reserved to factories: broadband, token management, less production Slide 45 Laurent Toutain RES 30 Token Management IEEE Model IEEE groups overview B C D How to manage token circulation on a bus? What his the next equipment? How new equipments can enter into the network? What append if the token disappear? Expensive technology, reserved to factories: broadband, token management, less production Slide 45 Laurent Toutain RES 30

67 Token Management IEEE Model IEEE groups overview B C D How to manage token circulation on a bus? What his the next equipment? How new equipments can enter into the network? What append if the token disappear? Expensive technology, reserved to factories: broadband, token management, less production Slide 45 Laurent Toutain RES 30 Token Management IEEE Model IEEE groups overview G B C D How to manage token circulation on a bus? What his the next equipment? How new equipments can enter into the network? What append if the token disappear? Expensive technology, reserved to factories: broadband, token management, less production Slide 45 Laurent Toutain RES 30

68 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Slide 46 Laurent Toutain RES 30 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Equipment sends all the traffic on the point to point link Slide 46 Laurent Toutain RES 30

69 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Equipment sends all the traffic on the point to point link Other equipment repeats all the traffic on the point to point link Slide 46 Laurent Toutain RES 30 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Source removes the frame Equipment sends all the traffic on the point to point link Other equipment repeats all the traffic on the point to point link Slide 46 Laurent Toutain RES 30

70 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Source removes the frame Equipment sends all the traffic on the point to point link Repeating frames from PtP link to PtP link creates a broadcast network. ddresses create a Point to Point network on that broadcast network Other equipment repeats all the traffic on the point to point link Slide 46 Laurent Toutain RES 30 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Slide 46 Laurent Toutain RES 30

71 IEEE 802.5; Token Ring IEEE Model IEEE groups overview MU Slide 46 Laurent Toutain RES 30 IEEE 802.5; Token Ring IEEE Model IEEE groups overview Medium ttachment Unit (MU) emulates ring topology. Real topology is a start topology MU detects if an equipment is down. In that case it is excluded from the ring MU lmost all the LN are based on that topology, cabling is the same, only the central equipment gives the nature of the network. Slide 46 Laurent Toutain RES 30

72 Token Ring management IEEE Model IEEE groups overview Token management is simpler than Token Bus; Token follow the physical link No need to address the token destination, just send it on the wire Token Ring was very popular: Supported by IBM, Offer some delays guaranties Two speeds 4 Mbit/s the 6 Mbits 00 MBit/s standardization arrived too late Some proprietaries solutions exists, but without standards it was risky to move Ethernet evolutions: 00Mbit/s, switching made Token Ring not so competitive Slide 47 Laurent Toutain RES 30 IEEE 802.6; Distribute Queue Dual Bus IEEE Model IEEE groups overview Protocol for Metropolitan rea Networks: Long propagation delay None of the original solutions (shared Ethernet, Token Bus or Token Ring have good performances if propagation delays are high) Based on two buses, each with a direction: slot generator gives the place where equipment can send information Equipments knows their and others positions. Send information on the right bus to reach the destination To maintain fairness between equipments, DQDB develops an algorithm: set a bit to one on slot going the opposite way. when receiving a slot with a bit set to one, don t use the slot Slide 48 Laurent Toutain RES 30

73 DQDB IEEE Model IEEE groups overview B C D Slot generator Slide 49 Laurent Toutain RES 30 DQDB IEEE Model IEEE groups overview B C D B D Slide 49 Laurent Toutain RES 30

74 DQDB IEEE Model IEEE groups overview B C D B D Slide 49 Laurent Toutain RES 30 DQDB IEEE Model IEEE groups overview B C D B D Must leave a slot free on the other channel Slide 49 Laurent Toutain RES 30

75 DQDB IEEE Model IEEE groups overview B C D B D TM Slide 49 Laurent Toutain RES 30 DQDB IEEE Model IEEE groups overview No real fairness: End equipments got more bandwidth than central ones. Last attempt to use a distributed shared media: TM was used instead Star topology around a switch; lso based on fixed slots (cells) then Ethernet switched mode has no distance limitation optical fiber allows long distance Metro Internet Forum focuses on those architectures: add scalability add flow separation between groups of users. Slide 50 Laurent Toutain RES 30

76 IEEE IEEE Model IEEE groups overview Technical dvisery Group (TG): don t produce standards, help other groups and make liaison with other organizations IEEE 802.7: Broadband IEEE 802.8: Optical Fiber IEEE 802.9: Integrated Services LN (isoethernet) Share physically telephony and data networks frequency Ethernet 0M ISDN Too expensive and too limited replace with Voice over IP (VoIP) voice is digitalized and put into frames possible with the throughput raise and frame switching Slide 5 Laurent Toutain RES 30 IEEE 802.0; Security IEEE Model IEEE groups overview Cypher frames on the LN client serv. attack router Internet Slide 52 Laurent Toutain RES 30

77 IEEE 802.0; Security IEEE Model IEEE groups overview Cypher frames on the LN client serv. password attack router Internet Slide 52 Laurent Toutain RES 30 IEEE 802.0; Security IEEE Model IEEE groups overview Cypher frames on the LN client serv. Promiscuous mode, read all the frames on the link password attack password router Internet Slide 52 Laurent Toutain RES 30

78 IEEE 802.0; Security IEEE Model IEEE groups overview Cypher frames on the LN client serv. Promiscuous mode, receives cyphered frames attack router Internet Password is not cyphered Slide 52 Laurent Toutain RES 30 IEEE 802.0; Security IEEE Model IEEE groups overview Cypher frames on the LN client serv. attack router Internet only efficient on LN t layer 3 (IPsec) or 7 (TLS) cyphering is end-to-end Ethernet with switching makes this attack impossible Wi-Fi uses WEP or WP (IEEE 802.i) Slide 52 Laurent Toutain RES 30

79 IEEE IEEE Model IEEE groups overview IEEE 802.: Wi-Fi since IEEE 802.b (shared Mbit/s) Evolution up to 00 MBit/s See later in this class IEEE 802.2: ttempt to develop a 00 Mbit/s network: failure IEEE 802.3: does not exist IEEE 802.4: Cable Television Network: failure ITU succeed with DOSCIS (J.2, J.22, J.222) Slide 53 Laurent Toutain RES 30 IEEE IEEE Model IEEE groups overview : Bluetooth : : UWB Ultra Wide Band network: Dismantled : WSN Wireless Sensor Network Low Power Network Used by ZigBee, 6LoWPN (IETF) Slide 54 Laurent Toutain RES 30

80 IEEE 802.6: WiMX IEEE Model IEEE groups overview Oct 2004 : Publication of IEEE standard, first WiMX complete standard, known as Fixed WiMX. Based on OFDM PHYsical Layer dvertisement Range: 50 kms Practical value: 5-0 kms Dec 2005 : 802.6e amendment of 802.6, base of Mobile WIMX technology 200 : 802.6m Next generation of WiMX. Data rates of the order of 00 Mb/s, designed as a 4G cellular network (competitor to LTE) Slide 55 Laurent Toutain RES 30 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30

81 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview Sent on both rings More details see: Slide 56 Laurent Toutain RES 30

82 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview Take only one signal More details see: Slide 56 Laurent Toutain RES 30 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30

83 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview other link is up More details see: Slide 56 Laurent Toutain RES 30

84 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30

85 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview More details see: Slide 56 Laurent Toutain RES 30

86 IEEE 802.7: Resilient Packet Ring IEEE Model IEEE groups overview Ethernet Convergence Layer More details see: Slide 56 Laurent Toutain RES 30 IEEE IEEE Model IEEE groups overview IEEE and IEEE : TG Radio Regulatory: Liaison with other standardization bodies (such as ITU-T) Wireless Coexistence: How standards can work together in the unlicensed frequencies. IEEE : Mobility IEEE 802.2: hand over IEEE : Regional IEEE : Emergency Services Slide 57 Laurent Toutain RES 30

87 loha loha loha Simplest protocol on a shared media Send when a station want to send Does not listen to neighbor s traffic Collisions (two stations sending at the same time) can occur Unreceived messages are sent again latter. Was primary used by Hawaiian universities works well when traffic is very limited unstable when the network is loaded loha is not CSM since the media is not sensed before sending Slide 59 Laurent Toutain RES 30

88 loha Hypothesis ll messages have the same size and the then the same duration The number of stations is The global traffic can be modelized by a Poisson process Inter-arrival is given by an exponential law T : Message duration λ: number of messages generated in the system per second g: number of messages sent per second s: number of successful messages per second message without any collision Reminder: for a Poisson process with parameter g the probability of having k messages during a period T is P k (T ) = (gt )k e gt k! Slide 60 Laurent Toutain RES 30 loha First step: no retransmission λ: number of messages generated in the system per second g: number of messages sent per second, g = λ s: number of successful messages per second No other transmission No transmission T T P Succ = P 0 (2T ) = (2gT )0 e 2gT 0! = e 2gT P Succ = s g TransmissionNumber = g s Slide 6 Laurent Toutain RES 30

89 loha S and G Normalized throughput G = g.t percentage of successful transmission Offered load S = s.t percentage of channel usage can be > s Slide 62 Laurent Toutain RES 30 loha S and G Normalized throughput G = g.t percentage of successful transmission Offered load S = s.t percentage of channel usage can be > s Slide 62 Laurent Toutain RES 30

90 loha S and G Normalized throughput G = g.t percentage of successful transmission Offered load S = s.t percentage of channel usage can be > s Slide 62 Laurent Toutain RES 30 loha S and G Normalized throughput G = g.t percentage of successful transmission Offered load S = s.t percentage of channel usage can be > s Slide 62 Laurent Toutain RES 30

91 loha S and G Normalized throughput G = g.t percentage of successful transmission Offered load S = s.t percentage of channel usage can be > s Slide 62 Laurent Toutain RES 30 loha S and G Normalized throughput G = g.t percentage of successful transmission Offered load S = s.t percentage of channel usage can be > s Slide 62 Laurent Toutain RES 30

92 loha Performance of non-slotted loha S G Non Slotted P Succ = e 2gT = s g and G = gt, S = st S = G.e 2G The maximum of S is /2e for G = /2 Slide 63 Laurent Toutain RES 30 loha Performance of non-slotted loha S G Non Slotted P Succ = e 2gT = s g and G = gt, S = st S = G.e 2G The maximum of S is /2e for G = /2 Slide 63 Laurent Toutain RES 30

93 loha loha with a retransmission procedure λ: number of messages generated in the system per second g: number of messages sent per second rriving messages (fresh load) plus retransmissions s: number of successful messages per second message without any collision when the system works correctly s = λ The global transmission process is assumed to be a Poisson process Same result: S = G.e 2G but S is fixed G is to determined G/S gives the average number of transmissions per message Slide 64 Laurent Toutain RES 30 loha Slotted loha: Success Probability No transmission T P Succ = P 0 (T ) = (gt )0 e gt 0! = e gt = e G P Succ = S G S = G.e G Slide 65 Laurent Toutain RES 30

94 S Slotted G Non Slotted Slide 66 Laurent Toutain RES 30 S Slotted G Non Slotted Non Slotted loha: max 8% of the channel bandwidth Slide 66 Laurent Toutain RES 30

95 S Slotted G Non Slotted Non Slotted loha: max 8% of the channel bandwidth Slotted loha: max 36% of the channel bandwidth Slide 66 Laurent Toutain RES 30 S Slotted G Non Slotted Non Slotted loha: max 8% of the channel bandwidth Slotted loha: max 36% of the channel bandwidth When this limit is reached, system become instable Before the limit, increasing the load increase success fter the limit, increasing the load, decrease success Slide 66 Laurent Toutain RES 30

96 S Slotted G Non Slotted Non Slotted loha: max 8% of the channel bandwidth Slotted loha: max 36% of the channel bandwidth When this limit is reached, system become instable Before the limit, increasing the load increase success fter the limit, increasing the load, decrease success Getting closer to limit, increases instability risk Slide 66 Laurent Toutain RES 30 loha CSM: Carrier Sense Multiple ccess Listen to channel before sending Easy with wired technologies, difficult with wireless τ T Slide 67 Laurent Toutain RES 30

97 loha CSM: Carrier Sense Multiple ccess Listen to channel before sending Easy with wired technologies, difficult with wireless Propagation Delay τ Transmission Time Latency a = τ T = τ.throughput L frame T 0 4 < LN Latency < 0 2 Slide 67 Laurent Toutain RES 30 loha CSM: Carrier Sense Multiple ccess Listen to channel before sending Easy with wired technologies, difficult with wireless τ Collision due to propagation delays T Transmission stopped due to channel activity Collision Slide 67 Laurent Toutain RES 30

98 loha CSM: Carrier Sense Multiple ccess Listen to channel before sending Easy with wired technologies, difficult with wireless τ Collision due to propagation delays T Transmission stopped due to channel activity Send immediatly after silence: -persistent (Ethernet) Collision Send immediatly with probability p, wait a time slot with probability p: p-persistant (Wi-Fi) Slide 67 Laurent Toutain RES 30 loha ccess Method comparison Slide 68 Laurent Toutain RES 30

99 Ethernet Introduction History and Evolutions Ethernet Introduction Developed initially by Digital, Intel and Xerox to share first laser printers First version in 976 at 3 Mbit/s Second version standardized by IEEE at 0 Mbit/s: Subtle changes in frame field leads to two way to manage protocol stack. Frame format slightly changed but physical medium evolved: from 0 Mbit/s to 00 MBit/s them GBit/s and 0 or 40 GBit/s. standardization is currently working on 00 GBit/s links. From coaxial link to twisted pair and optical fiber (No support for radio link) MC get simplified: Shared media (coaxial or twisted pair with hub) uses CSM/CD algorithm Switched media or point to point links do not require MC algorithm (there is a dedicated resource between the equipment and the switch). Slide 70 Laurent Toutain RES 30

100 Ethernet IEEE at 0 Mbit/s Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Slide 72 Laurent Toutain RES 30

101 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Slide 72 Laurent Toutain RES 30 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Slide 72 Laurent Toutain RES 30

102 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial Slide 72 Laurent Toutain RES 30 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial Slide 72 Laurent Toutain RES 30

103 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial 500 m Slide 72 Laurent Toutain RES 30 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial vampire Slide 72 Laurent Toutain RES 30

104 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial vampire transceiver Slide 72 Laurent Toutain RES 30 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial vampire transceiver drop cable Network Card Slide 72 Laurent Toutain RES 30

105 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial vampire transceiver drop cable Network Card Slide 72 Laurent Toutain RES 30 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial vampire transceiver Physical Layer Signaling MC PLS ttachment Unit Interface drop cable Network Card Physical Media ttachment ttachment Unit Interface PM Slide 72 Laurent Toutain RES 30

106 Technology names: 0BSE-5 & 0BSE-2 Ethernet IEEE at 0 Mbit/s 0BSE-T Speed: 0, 00, 000, 0G, 40G, 00G Modulation: BROD, BSE, EPON Physical Layer: 5, 2, Tx, Fx,... Obsoleted technologies: 0BSE-5 (Thick Ethernet) and 0BSE-2 (Thin Ethernet) Based on co-axial vampire transceiver Physical Layer Signaling MC PLS ttachment Unit Interface drop cable Network Card Media ttachment Unit = transceiver Physical Media ttachment ttachment Unit Interface PM Slide 72 Laurent Toutain RES 30 0BSE-T Ethernet IEEE at 0 Mbit/s Hub < 00m Hub: ctive equipment repeating signal on other ports Generate collision signal when two equipments send at the same time Hub is viewed as a shared network by equipments. More reliable than co-axial cable. Cable cut just isolates one equipment. Use standard wires (telephony wires for 0BSE-T) Slide 73 Laurent Toutain RES 30

107 0BSE-T Ethernet IEEE at 0 Mbit/s Hub Hub: ctive equipment repeating signal on other ports Generate collision signal when two equipments send at the same time Hub is viewed as a shared network by equipments. More reliable than co-axial cable. Cable cut just isolates one equipment. Use standard wires (telephony wires for 0BSE-T) Slide 73 Laurent Toutain RES 30 0BSE-T Ethernet IEEE at 0 Mbit/s Hub Hub: ctive equipment repeating signal on other ports Generate collision signal when two equipments send at the same time Hub is viewed as a shared network by equipments. More reliable than co-axial cable. Cable cut just isolates one equipment. Use standard wires (telephony wires for 0BSE-T) Slide 73 Laurent Toutain RES 30

108 0BSE-T Ethernet IEEE at 0 Mbit/s Hub Hub: ctive equipment repeating signal on other ports Generate collision signal when two equipments send at the same time Hub is viewed as a shared network by equipments. More reliable than co-axial cable. Cable cut just isolates one equipment. Use standard wires (telephony wires for 0BSE-T) Slide 73 Laurent Toutain RES 30 RJ-45 Ethernet IEEE at 0 Mbit/s RJ-45 plug and cable contains 4 twisted pairs 0M and 00M generally use only 2 pairs, G uses 4 pairs Modulation signal is the difference between both wires PoE (Power on Ethernet) (IEEE 802.3at): continuous voltage is added to data or use the blue and brown pairs Straight cable to connect equipment to switch/hub, cross cable to connect equipment/switch/hub together equipments may select to the appropriate cabling. Transmit+ DC+ 2 Transmit- DC+ 2 3 Receive+ DC Receive- DC Straight Cable Cross Cable nikkel/ethernetcables.html Slide 74 Laurent Toutain RES 30

109 Coding technique at 0 Mbit/s Ethernet IEEE at 0 Mbit/s Manchester coding: transition 0 = transition 0 = 0 Each bit sent allows clock synchronization by the receiver Cannot be used a 00 Mbit/s and higher due to the high number of transitions +V -V code Slide 75 Laurent Toutain RES 30 Ethernet 00 Mbit/s

110 Ethernet 00 Mbit/s on Twisted Pairs Ethernet 00 Mbit/s Only based on star topologies (hub or switch); 00BSE-T2 (cat 3) 00 Mbit/s 00 Mbit/s 50 Mbit/s T 50 Mbit/s R 50 Mbit/s T 50 Mbit/s R H H 25 Mbaud 25 Mbaud H H 50 Mbit/s T 50 Mbit/s R 50 Mbit/s T 50 Mbit/s R 00 Mbit/s 00 Mbit/s 00BSE-T4 (cat 3) half-duplex 8B/6T (T=-/0/+) 2 8 = 256 < 3 6 = Mbits/s 25 Mbit/s 25 Mbit/s 25 Mbit/s sosa sosa sosb data2...datan+ eop2 eop5 00 Mbits/s p3 sosa sosa sosb data3...datan eop3 p4 sosa sosb data... eop eop Slide 77 Laurent Toutain RES 30 00Base-TX coding Ethernet 00 Mbit/s Use 4B/5B coding (4 bits are coded into 5 bits). Binary values 5B Binary values 5B Signal 5B Meaning Q Quiet (signal lost) I Idle J 000 Start # B 0 0 K 000 Start # C T 00 End D 0 0 R 00 Reset E 0 00 S 00 Set F 0 H 0000 Halt Coding uses MLT-3 +V are alternatively coded by +V and -V, 0 are coded with 0V -V Which value is sent? Slide 78 Laurent Toutain RES 30

111 00Base-TX coding Ethernet 00 Mbit/s Use 4B/5B coding (4 bits are coded into 5 bits). Binary values 5B Binary values 5B Signal 5B Meaning Q Quiet (signal lost) I Idle J 000 Start # B 0 0 K 000 Start # C T 00 End D 0 0 R 00 Reset E 0 00 S 00 Set F 0 H 0000 Halt Coding uses MLT-3 +V are alternatively coded by +V and -V, 0 are coded with 0V V Which value is sent? 0xC, 0x, 0xB Slide 78 Laurent Toutain RES 30 Ethernet 00 Mbit/s on Optical Fiber Ethernet 00 Mbit/s 00BSE-FX Multimode Optical Fiber up to 2 km in switched full duplex mode limited to 400 m in half duplex CSM/CD mode 00BSE-SX Cheaper lasers, less distance, about 550 m. 00BSE-LX Up to 0 km monomode fiber... Slide 79 Laurent Toutain RES 30

112 Ethernet Gbit/s Ethernet 00 Mbit/s 000BSE-T (IEEE 802.3ab) category 5 cable and over all 4 pairs up to 00 m 4-pair category 5 UTP PM5 code symbols PM5 code symbols 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s TDX RDX TDX RDX TDX RDX TDX RDX T R T R T R T R H H H H 25 Mbaud 25 Mbaud 25 Mbaud 25 Mbaud H H H H T R T R T R T R TDX RDX TDX RDX TDX RDX TDX RDX 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s 250 Mbit/s Slide 80 Laurent Toutain RES BSE-X Ethernet 00 Mbit/s 000BSE-TX Use two twisted pairs of cat6 cable, using 8B/0B coding less popular than 000BSE-T widely deployed on computers 000BSE-CX (IEEE 802.3z) initial standard for twisted pair on a max distance of 25 m, replaced by 000BSE-T 000BSE-LX Multi-mode optical fiber, up to BSE-ZX Single mode optical fiber, up to 70 km... Slide 8 Laurent Toutain RES 30

113 Ethernet CSM/CD Carrier Sense Multiple ccess / Collision Detect Ethernet CSM/CD Carrier Sense: Listen to the channel to detect the status Idle: Not transmission Busy: Regular transmission is occuring Collision: Several equipments are sending at the same time. Standard impose that signal level cannot be reduce by more than half in the whole link If reception level is higher than the standardized transmission level, then at least two equipments are sending. This not work on radio network, reception level is much smaller than transmission lever and some station may be hidden if the channel is Idle, then send the frame if the channel is busy, then delay the transmission Collision Detect: If a collision occurs during the frame transmission: stop and restart. Impossible to detect on radio links Slide 83 Laurent Toutain RES 30

114 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30 CSM/CD Ethernet CSM/CD wants to send a frame Slide 84 Laurent Toutain RES 30

115 CSM/CD Ethernet CSM/CD probes the canal: Idle frame can be sent Slide 84 Laurent Toutain RES 30 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30

116 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30

117 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30

118 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30

119 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30

120 CSM/CD Ethernet CSM/CD Slide 84 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C is sending C wants to send C Slide 85 Laurent Toutain RES 30

121 CSM/CD: Delayed transmission Ethernet CSM/CD C C listen to the channel: Busy Delay until channel becomes idle C Slide 85 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30

122 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30

123 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30

124 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C Channel becomes idle C starts sending C Slide 85 Laurent Toutain RES 30

125 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30

126 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30

127 CSM/CD: Delayed transmission Ethernet CSM/CD C C Slide 85 Laurent Toutain RES 30 CSM/CD: Collision Ethernet CSM/CD C wants to send a frame probes the canal: Idle frame can be sent C wants to send a frame C probes the canal: Idle frame can be sent C Slide 86 Laurent Toutain RES 30

128 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30

129 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30 CSM/CD: Collision Ethernet CSM/CD C and C detect the collision Continue to send some bit to allow other equipments to detect the collision, then stop C Slide 86 Laurent Toutain RES 30

130 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30

131 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30

132 CSM/CD: Collision Ethernet CSM/CD C C Slide 86 Laurent Toutain RES 30 CSM/CD: Minimal frame size Ethernet CSM/CD C G C G Slide 87 Laurent Toutain RES 30

133 CSM/CD: Minimal frame size Ethernet CSM/CD C G C G Slide 87 Laurent Toutain RES 30 CSM/CD: Minimal frame size Ethernet CSM/CD C G send succefully its frame, even if some of the equipment on the link will not receive it due to collision C G Slide 87 Laurent Toutain RES 30

134 CSM/CD: Minimal frame size Ethernet CSM/CD C G Solution: rtificially raise the frame size until this problem could append. This way will be aware that its frame got a collision. C G Slide 87 Laurent Toutain RES 30 CSM/CD: Minimal frame size Ethernet CSM/CD C G C G Slide 87 Laurent Toutain RES 30

135 CSM/CD: Minimal frame size Ethernet CSM/CD C G Collision detected during the transmission.. C G Slide 87 Laurent Toutain RES 30 CSM/CD: Minimal frame size Ethernet CSM/CD C G? What is the length of these period? C G Slide 87 Laurent Toutain RES 30

136 CSM/CD: Minimal frame size computation Ethernet CSM/CD G G Slide 88 Laurent Toutain RES 30 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Take the worst case: equipments Larger distance between G Slide 88 Laurent Toutain RES 30

137 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Max. prop. delay first bit G Slide 88 Laurent Toutain RES 30 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Max. prop. Max. prop. delay delay first bit first bit G Slide 88 Laurent Toutain RES 30

138 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Max. prop. Max. prop. delay delay first bit first bit No possible collision G Slide 88 Laurent Toutain RES 30 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Max. prop. Max. prop. delay delay first bit first bit Min frame = 2.MaxPropagationDelay G Slide 88 Laurent Toutain RES 30

139 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Max. prop. Max. prop. delay delay first bit first bit Min frame = 2.MaxPropagationDelay t 0 Mbit/s standard gives: MaxPropagationDelay = 5.2µs G Slide 88 Laurent Toutain RES 30 CSM/CD: Minimal frame size computation Ethernet CSM/CD G Max. prop. Max. prop. delay delay first bit first bit Min frame = 2.MaxPropagationDelay t 0 Mbit/s standard gives: MaxPropagationDelay = 5.2µs Min frame = 64Bytes G Slide 88 Laurent Toutain RES 30

140 Maximum Frame size Ethernet CSM/CD Slide 89 Laurent Toutain RES 30 Maximum Frame size Ethernet CSM/CD senses the channel: Idle send frame Slide 89 Laurent Toutain RES 30

141 Maximum Frame size Ethernet CSM/CD B senses the channel: Idle send frame B senses the channel: Busy wait until channel becomes Idle Slide 89 Laurent Toutain RES 30 Maximum Frame size Ethernet CSM/CD B C senses the channel: Idle send frame B senses the channel: Busy wait until channel becomes Idle C senses the channel: Busy wait until channel becomes Idle Slide 89 Laurent Toutain RES 30

142 Maximum Frame size Ethernet CSM/CD B C Collision senses the channel: Idle send frame B senses the channel: Busy wait until channel becomes Idle C senses the channel: Busy wait until channel becomes Idle and C send frame at the same time collision Slide 89 Laurent Toutain RES 30 Maximum Frame size Ethernet CSM/CD B C Collision senses the channel: Idle send frame B senses the channel: Busy wait until channel becomes Idle C senses the channel: Busy wait until channel becomes Idle and C send frame at the same time collision Maximum Frame Size Standard fixes the Max frame = 500 Bytes. Slide 89 Laurent Toutain RES 30

143 Frame Length Ethernet CSM/CD Minimum 64 Bytes is given by CSM/CD propagation delays ll versions of the standard impose this limit. Maximum 500 Bytes is given by the collision propability This value is very small If CSM/CD is disabled, this value can be up to 9 Kilobyte Jumboframe Can be use either: to increase transmission speed (reduce copy from card to memory) to allow VLN by adding a value to give a virtual network number to encapsulate Ethernet frame into another Ethernet frame (used by Metro Ethernet) Slide 90 Laurent Toutain RES 30 Binary Exponential Backoff Ethernet CSM/CD Previous slides shows that collisions can occur after the busy period. Each equipment must have a different behavior: Otherwise a new collision is generated Based on random number First attempt: draw a random number d between [0, ]; Wait 5.2 d µs. B C Collision Slide 9 Laurent Toutain RES 30

144 Binary Exponential Backoff Ethernet CSM/CD Previous slides shows that collisions can occur after the busy period. Each equipment must have a different behavior: Otherwise a new collision is generated Based on random number First attempt: draw a random number d between [0, ]; Wait 5.2 d µs. d [0 ] B ; d [0 ] C = B C Collision Slide 9 Laurent Toutain RES 30 Binary Exponential Backoff Ethernet CSM/CD Previous slides shows that collisions can occur after the busy period. Each equipment must have a different behavior: Otherwise a new collision is generated Based on random number First attempt: draw a random number d between [0, ]; Wait 5.2 d µs. d [0 ] B ; d [0 ] C = B C B Collision Slide 9 Laurent Toutain RES 30

145 Binary Exponential Backoff Ethernet CSM/CD Previous slides shows that collisions can occur after the busy period. Each equipment must have a different behavior: Otherwise a new collision is generated Based on random number First attempt: draw a random number d between [0, ]; Wait 5.2 d µs. d [0 ] B ; d [0 ] C = B C B C Collision Slide 9 Laurent Toutain RES 30 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C Collision Slide 92 Laurent Toutain RES 30

146 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C Collision Slide 92 Laurent Toutain RES 30 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C d [0 3] C = 3; d [0 ] = Collision Collision Slide 92 Laurent Toutain RES 30

147 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C d [0 3] C 3 = 3; d [0 ] = Collision Collision Slide 92 Laurent Toutain RES 30 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C d [0 3] C 3 = 3; d [0 ] = 2 Collision Collision Slide 92 Laurent Toutain RES 30

148 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C d [0 3] C 3 = 3; d [0 ] = 2 Collision Collision Slide 92 Laurent Toutain RES 30 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C d [0 3] C 3 = 3; d [0 ] = C 2 Collision Collision Slide 92 Laurent Toutain RES 30

149 Binary Exponential Backoff (continued) Ethernet CSM/CD In the previous example, if both equipment draws a different random number, the collision is solved if both select the same number, the collision occurs again. The space double every attempt until the0 th then remains the same until the 6 th If after 6 attempts the frame is not sent, the transmission is aborded. No guaranty (and not guaranteed delay) to send a frame. d [0 ] B B C = 0; d [0 ] C = B C d [0 3] C 3 = 3; d [0 ] = C 2 Collision Collision Slide 92 Laurent Toutain RES 30 CSM/CD and 00 Mbit/s Ethernet CSM/CD t 0 Mbit/s, standard mandate at minimum duration of 5.2 µs or 64 Bytes t 00 Mbit/s if the same duration is taken, the minimal frame size must be increased to 640 Bytes no gain: small frame sending time remains the same (5.2 µs) when bridging from 00BSE-TX to 0BSE-T, duration will be increased (52 µs) So at 00 MBit/s, minimum duration is 5.2 µs Minimum size remain compatible with 0 Mbit/s technologies Network size must be decreased by a factor 0 0BSE-5 allowed 2.5 km 00BSE-TX allows 250 m Compatible with cabling constraints Slide 93 Laurent Toutain RES 30

150 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 94 Laurent Toutain RES 30 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30

151 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30

152 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30

153 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30

154 Questions Ethernet CSM/CD n shared Ethernet network can be 0 km long? n shared Ethernet network can be 0 cm long? n switched Ethernet network can be 0 km long? n switched Ethernet network can be 0 cm long? 64 Bytes are not necessary in switched mode We have the guaranty that a frame is sent in less than 6 attempts CSM/CD guaranty that frames are sent is the same order they are submitted to the MC layer CSM/CD can be used with 00BSE-TX and GBSE-TX F T Slide 95 Laurent Toutain RES 30 Ethernet Switching

155 Switching Ethernet Switching Hub Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching Hub Slide 97 Laurent Toutain RES 30

156 Switching Ethernet Switching Hub Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching Switch Slide 97 Laurent Toutain RES 30

157 Switching Ethernet Switching Switch Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching Switch Slide 97 Laurent Toutain RES 30

158 Switching Ethernet Switching Collision domains: Equipment and switch cannot send simultaneously due to CSM/CD Switch Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching Collision domains: Equipment and switch cannot send simultaneously due to CSM/CD If CSM/CD is disabled, equipment and switch can send simultaneously since there is a dedicated channel for both ways full duplex Switch Slide 97 Laurent Toutain RES 30

159 Switching Ethernet Switching Switch Multiply by 5 the network capacity compared to an hub Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching Switch Multiply by 5 the network capacity compared to an hub Really? Slide 97 Laurent Toutain RES 30

160 Switching Ethernet Switching traffic is not symmetric but goes or comes from some specific equipments (file servers, routers,... Switch Multiply by 5 the network capacity compared to an hub Really? Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching R 7 R 9 R 0 R Switch R 3 R 4 R * R R5 Slide 97 Laurent Toutain RES 30

161 Switching Ethernet Switching R 7 R 9 R 0 R Switch Bottleneck frame losses R 3 R 4 R * R R5 Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching R 7 R 9 R 0 R Switch Switches mandate the use of flow control mechanisms Bottleneck frame losses R 3 R 4 R * R R5 Slide 97 Laurent Toutain RES 30

162 Switching Ethernet Switching R Preamble Preamble Preamble Preamble Switch Switches mandate the use of flow control mechanisms Preamble Preamble Preamble Preamble 6 R R5 Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching R Preamble Preamble Preamble Preamble If equipments are half-duplex, switch can send preamble when saturated hub Switch Switches mandate the use of flow control mechanisms Preamble Preamble Preamble Preamble 6 R R5 Slide 97 Laurent Toutain RES 30

163 Switching Ethernet Switching R PUSE PUSE PUSE PUSE If equipments are fullduplex, switch can generate a PUSE message when saturated Switch Switches mandate the use of flow control mechanisms PUSE PUSE PUSE PUSE 6 R R5 Slide 97 Laurent Toutain RES 30 Switching Ethernet Switching BSE-TX 6 R 00BSE-TX 7 R 00BSE-TX 9 R 00BSE-TX 0 R Switch Switches mandate the use of flow control Increase mechanisms bandwidth on congestioned links 00BSE-TX R 00BSE-TX 3 R R5 4 R 00BSE-TX 000BSE-T * R Slide 97 Laurent Toutain RES 30

164 Ethernet uto-configuration uto-configuration Ethernet uto-configuration Slide 99 Laurent Toutain RES 30

165 uto-configuration Ethernet uto-configuration What are the switch/hub capabilities: 0BSE-T, 00BSE-TX, 000BSE-T? Full-duplex, Half-duplex? Same question for the equipment connected Same Media Dependant Interface (RJ-45) Find the best Ethernet technologies compatible to both ends uto-negociation Slide 99 Laurent Toutain RES 30 uto-configuration Ethernet uto-configuration MC PLS UI MU PM MDI Slide 99 Laurent Toutain RES 30

166 uto-configuration Ethernet uto-configuration MC PLS UI Link test: hen no traffic a pulse every 6ms switches on interface s leds 6 ms MU PM MDI 6 ms Slide 99 Laurent Toutain RES 30 uto-configuration Ethernet uto-configuration MC MC PLS RS MII 33 pulses odd pulses: separator event pulses: binary value (no pulse=0, pulse=) UI MU PM MDI PHY RJ-45 PCS PM PMD neg MDI 6 ms page page 2 page 3 S0-S4 0-7 RF ack NP S0:IEEE :0BaseT :0BaseT-FD 2:00BaseTX 3:00BaseTX-FD 4:00BaseT4 5:PUSE 6: sym PUSE 7: Reserved Slide 99 Laurent Toutain RES 30

167 uto-configuration Ethernet uto-configuration MC MC MC PLS RS RS MII GMII 33 pulses odd pulses: separator event pulses: binary value (no pulse=0, pulse=) UI MU PM MDI PHY RJ-45 PCS PM PMD neg MDI PHY RJ-45 PCS PM PMD MDI 6 ms page page 2 page 3 S0-S4 0-7 RF ack NP S0:IEEE :0BaseT :0BaseT-FD 2:00BaseTX 3:00BaseTX-FD 4:00BaseT4 5:PUSE 6: sym PUSE 7: Reserved 000BSE-T negociation 000BSE-T parameters Slide 99 Laurent Toutain RES 30 Ethernet Frame Format

168 Frame Format Ethernet Frame Format IFS preamble SDF Frame Slide 0 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 8 /J/K/ /T/R/ preamble SDF Frame Slide 0 Laurent Toutain RES 30

169 Frame Format Ethernet Frame Format 8 /I/I/ /I/I/ /I/I/ /J/K/ /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ preamble SDF Frame Slide 0 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 4 8 /I/I/ /I/I/ /I/I/ /J/K/ /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ CRC 64 length 58 preamble SDF Frame Slide 0 Laurent Toutain RES 30

170 Frame Format Ethernet Frame Format Software Hardware 4 8 /I/I/ /I/I/ /I/I/ /J/K/ /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ CRC 64 length 58 preamble SDF Frame Slide 0 Laurent Toutain RES 30 Frame Format Ethernet Frame Format Software Hardware 4 8 /I/I/ /I/I/ /I/I/ /J/K/ /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ CRC 64 length 58 preamble SDF Frame Slide 0 Laurent Toutain RES 30

171 Frame Format Ethernet Frame Format 6 Software Hardware Destination ddress 4 8 /I/I/ /I/I/ /I/I/ /J/K/ /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ CRC 64 length 58 preamble SDF Frame Slide 0 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 6 6 Software Hardware Destination ddress Source ddress 4 8 /I/I/ /I/I/ /I/I/ /J/K/ /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ CRC 64 length 58 preamble SDF Frame Slide 0 Laurent Toutain RES 30

172 Frame Format Ethernet Frame Format Software Hardware Destination ddress 4 8 /I/I/ /I/I/ /I/I/ /J/K/ Source ddress /T/R/ L3 Proto. /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ CRC 64 length 58 preamble SDF Frame Slide 0 Laurent Toutain RES 30 Frame Format Ethernet Frame Format Software Hardware Destination ddress Source ddress L3 Proto. Padding 4 /I/I/ /I/I/ /I/I/ /J/K/ x0800: IPv4 0x0806: RP 0x800: VLN 0x86dd: IPv6 0x8808: MC control 64 length 58 CRC /T/R/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ /I/I/ preamble SDF Frame Slide 0 Laurent Toutain RES 30

173 Frame Format Ethernet Frame Format Destination ddress Source ddress L3 Proto. CRC Slide 02 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 40 Bytes TCP/IP Destination ddress Source ddress L3 Proto. CRC Slide 02 Laurent Toutain RES 30

174 Frame Format Ethernet Frame Format 40 Bytes TCP/IP Destination ddress Source ddress 0x0800 CRC Slide 02 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 40 Bytes TCP/IP Destination ddress Source ddress 0x0800 CRC Destination ddress Source ddress 0x0800 CRC Slide 02 Laurent Toutain RES 30

175 Frame Format Ethernet Frame Format 40 Bytes TCP/IP TCP/IP Destination ddress Source ddress 0x0800 CRC Destination ddress Source ddress 0x0800 CRC Slide 02 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 40 Bytes 40 Bytes TCP/IP TCP/IP Destination ddress Source ddress 0x0800 CRC Destination ddress Source ddress 0x0800 CRC Slide 02 Laurent Toutain RES 30

176 Frame Format Ethernet Frame Format 40 Bytes 40 Bytes TCP/IP TCP/IP Destination ddress Source ddress 0x0800 CRC Destination ddress Source ddress 0x0800 CRC Slide 02 Laurent Toutain RES 30 Frame Format Ethernet Frame Format 40 Bytes 40 Bytes TCP/IP TCP/IP Destination ddress Source ddress 0x0800 CRC Destination ddress Source ddress 0x0800 CRC ISO Layer violation Slide 02 Laurent Toutain RES 30

177 Frame Format Ethernet Frame Format 40 Bytes TCP/IP Works only if L3 may find its own length (e.g. IP) 40 Bytes TCP/IP Destination ddress Source ddress 0x0800 CRC Destination ddress Source ddress 0x0800 CRC ISO Layer violation Slide 02 Laurent Toutain RES 30 Ethernet vs IEEE Ethernet Frame Format Destination ddress Source ddress L3 Proto. CRC Slide 03 Laurent Toutain RES 30

178 Ethernet vs IEEE Ethernet Frame Format Destination ddress Source ddress data length CRC Slide 03 Laurent Toutain RES 30 Ethernet vs IEEE Ethernet Frame Format Logical Link Control Destination ddress Source ddress data length CRC Slide 03 Laurent Toutain RES 30

179 Ethernet vs IEEE Ethernet Frame Format Logical Link Control ll IEEE solutions mandate (like Wi-Fi) a LLC layer to at least carry the L3 protocol, except Ethernet which may use the third field to carry the L3 protocol if compatible Destination ddress Source ddress data length CRC if 500: IEEE if > 500: Ethernet Slide 03 Laurent Toutain RES 30 Questions Ethernet Frame Format 0x0000: 080 c e79e dae x000: b x0020: e79e d80 802e x0030: f This dump gives a IEEE frame: - What is the nature of the destination address? - What is the nature of the frame (Ethernet or IEEE 802.3)? - Can you identify padding bytes? - Can you give the frame CRC? Slide 04 Laurent Toutain RES 30

180 Questions Ethernet Frame Format 0: x0000: 080 c e79e dae x000: b x0020: e79e d80 802e x0030: f This dump gives a IEEE frame: - What is the nature of the destination address? Multicast (first bit sent = ) - What is the nature of the frame (Ethernet or IEEE 802.3)? - Can you identify padding bytes? - Can you give the frame CRC? Slide 05 Laurent Toutain RES 30 Questions Ethernet Frame Format 0: < 500 IEEE x0000: 080 c e79e dae x000: b x0020: e79e d80 802e x0030: f This dump gives a IEEE frame: - What is the nature of the destination address? Multicast (first bit sent = ) - What is the nature of the frame (Ethernet or IEEE 802.3)? IEEE 802.3, EtherType is less than Can you identify padding bytes? - Can you give the frame CRC? Slide 05 Laurent Toutain RES 30

181 Questions Ethernet Frame Format 0: < 500 IEEE x0000: 080 c e79e dae x000: b x0020: e79e d80 802e x0030: f //////// 0000/////// 0000//////// This dump gives a IEEE frame: - What is the nature of the destination address? Multicast (first bit sent = ) - What is the nature of the frame (Ethernet or IEEE 802.3)? IEEE 802.3, EtherType is less than Can you identify padding bytes? Yes: length is 0x26 (2 lines 6 bytes) 8 last bytes are padding - Can you give the frame CRC? Slide 05 Laurent Toutain RES 30 Questions Ethernet Frame Format 0: < 500 IEEE x0000: 080 c e79e dae x000: b x0020: e79e d80 802e x0030: f //////// 0000/////// 0000//////// XXXX XXXX This dump gives a IEEE frame: Missing CRC - What is the nature of the destination address? Multicast (first bit sent = ) - What is the nature of the frame (Ethernet or IEEE 802.3)? IEEE 802.3, EtherType is less than Can you identify padding bytes? Yes: length is 0x26 (2 lines 6 bytes) 8 last bytes are padding - Can you give the frame CRC? No: It has been removed by the card Slide 05 Laurent Toutain RES 30

182 Ethernet: References Ethernet Frame Format Cisco tutorial: uto-configuration: Slide 06 Laurent Toutain RES 30 IEEE 802. Physical Layer

183 IEEE 802. Physical Layer IEEE 802. Standards LLC (Mandatory) MC (CSM/C) b 802.a 802.g 802.n Optique Infra Red 2.4 GHz FHSS (Frequency Hopping Spread Spectrum) 2.4 GHz DSSS (Direct- Sequence Spread Spectrum) 2.4 GHz CCK (Complementary Code Keying) 5 GHz OFDM (Orthogonal Frequency Division Multiplexing) 2.4 GHz OFDM (Orthogonal Frequency Division Multiplexing) 2.4 or 5 GHz OFDM + MINO 2 MBits 2 MBits 2 MBits Mbits 54 Mbits 54 Mbits 50 Mbits Slide 08 Laurent Toutain RES 30 Channels IEEE 802. Physical Layer (Japan) GHz IEEE 802.b 22 MHz GHz IEEE 802.a Pilot tone 20 MHz 52 sub carriers Slide 09 Laurent Toutain RES 30

184 Channels IEEE 802. Physical Layer (Japan) GHz IEEE 802.g/n 20 MHz GHz IEEE 802.a Pilot tone 20 MHz 52 sub carriers Slide 09 Laurent Toutain RES 30 Channels IEEE 802. Physical Layer (Japan) GHz IEEE 802.n 40 MHz GHz IEEE 802.a Pilot tone 20 MHz 52 sub carriers Slide 09 Laurent Toutain RES 30

185 WiFi Throughputs IEEE 802. Physical Layer Data Rate Transmission Type Modulation Scheme Standard (Mbit/s) DSSS Baker code & BPSK DSSS Baker code & QPSK DSSS CCK & QPSK 802.b/g 6 OFDM BPSK 802.a/g 9 OFDM BPSK 802.a/g 2 OFDM QPSK 802.a/g DSSS CCK & QPSK 802.b/g 8 OFDM QPSK 802.a/g 24 OFDM 6 QM 802.a/g 36 OFDM 6 QM 802.a/g 48 OFDM 64 QM 802.a/g 54 OFDM 64 QM 802.a/g Slide 0 Laurent Toutain RES 30 Modulations IEEE 802. Physical Layer BPSK: Binary Phase Shift Keying (20 MHz) Coding rate = /2 6 Mbit/s Coding rate = 3/4 9 Mbit/s QPSK: Quadrature Phase Shift Keying (20 MHz) Coding rate = /2 2 Mbit/s Coding rate = 3/4 8 Mbit/s 6-QM: Quadrature mplitude Modulation (20 MHz) Coding rate = /2 24 Mbit/s Coding rate = 3/4 36 Mbit/s 64-QM: Quadrature mplitude Modulation Coding rate = 2/3 48 Mbit/s Coding rate = 3/4 54 Mbit/s Slide Laurent Toutain RES 30

186 Versions compatibility IEEE 802. Physical Layer IEEE 802.b introduces short preamble ERP: Extended Rate Physical Long preamble: 92 bits or 92 µs Short preamble: 20 bits or 96 µs IEEE 802.g introduces OFDM 3 main physical layers ERP-DSSS/CCK: or 2 Mbit/s legacy physical layer ERP-OFDM: 6 to 54 MBit/s, pure OFDM Invisible from legacy nodes (IEEE 802. or IEEE 802.b) DSSS-OFDM: Start in DSSS and continue with OFDM Ensure compatibility with IEEE 802. and IEEE 802.b Slide 2 Laurent Toutain RES 30 Physical format IEEE 802. Physical Layer Preamble 28 bits 6 bits 8 bits 8 bits 6 bits 6 bits <0xFFF IEEE 802. Sync SDF Signal Service Length CRC PSDU (MPDU) BPSK: Mbit/s 92 µs Slide 3 Laurent Toutain RES 30

187 Physical format IEEE 802. Physical Layer 0x0: MBit/s 0x4: 2 MBit/s Preamble 28 bits 6 bits 8 bits 8 bits 6 bits 6 bits <0xFFF IEEE 802. Sync SDF Signal Service Length CRC PSDU (MPDU) BPSK: Mbit/s 92 µs Slide 3 Laurent Toutain RES 30 Physical format IEEE 802. Physical Layer Preamble 28 bits 6 bits 8 bits 8 bits 6 bits 6 bits <0xFFF IEEE 802. Sync SDF Signal Service Length CRC PSDU (MPDU) BPSK: Mbit/s 0x0: MBit/s 0x4: 2 MBit/s 92 µs 0x37: 5.5 MBit/s 0x6E: MBit/s number of µs to send PSDU x 6 + x 2 + x bits 6 bits 8 bits 8 bits 6 bits 6 bits <0xFFF IEEE 802.b Sync SDF Signal Service Length CRC PSDU (MPDU) BPSK: Mbit/s BPSK: 2 Mbit/s Slide 3 Laurent Toutain RES 30

188 Physical format IEEE 802. Physical Layer Preamble 0x0: 28 MBit/s bits 0x4: 6 bits2 8MBit/s bits 8 bits 0x37: 5.5 MBit/s 0x6E: MBit/s 0x0C: 6 MBit/s 0x8: 2 MBit/s IEEE0x24: 8Sync MBit/s 0x2C: SDF Signal 22 MBit/s Service x30: 24 MBit/s 0x42: 33 MBit/s 6 bits Length 0x48: 36 MBit/s 0x60: 48 MBit/s 0x6C: 54 MBit/s BPSK: Mbit/s 92 µs 6 bits CRC <0xFFF PSDU (MPDU) 56 bits 6 bits 8 bits 8 bits 6 bits 6 bits <0xFFF IEEE 802.g Sync SDF Signal Service Length CRC PSDU (MPDU) BPSK: Mbit/s BPSK: 2 Mbit/s OFDM Slide 3 Laurent Toutain RES 30 Questions IEEE 802. Physical Layer Is there compatibility problems between IEEE 802.a and IEEE 802.g? B = B IEEE 802. IEEE 802. IEEE 802.b IEEE 802.g IEEE 802.b IEEE 802.g Slide 4 Laurent Toutain RES 30

189 Questions IEEE 802. Physical Layer Is there compatibility problems between IEEE 802.a and IEEE 802.g? No since they do not use the same frequencies B = B IEEE 802. IEEE 802. IEEE 802.b IEEE 802.g IEEE 802.b IEEE 802.g Slide 5 Laurent Toutain RES 30 Questions IEEE 802. Physical Layer Is there compatibility problems between IEEE 802.a and IEEE 802.g? No since they do not use the same frequencies B = B IEEE 802. IEEE 802. Long IEEE 802.b IEEE 802.g IEEE 802.b Long IEEE 802.g Long Slide 5 Laurent Toutain RES 30

190 Questions IEEE 802. Physical Layer Is there compatibility problems between IEEE 802.a and IEEE 802.g? No since they do not use the same frequencies B = B IEEE 802. IEEE 802. Long IEEE 802.b Long IEEE 802.g IEEE 802.b Long Short IEEE 802.g Long Short Slide 5 Laurent Toutain RES 30 Questions IEEE 802. Physical Layer Is there compatibility problems between IEEE 802.a and IEEE 802.g? No since they do not use the same frequencies B = B IEEE 802. IEEE 802. Long IEEE 802.b Long IEEE 802.g Long DSSS-OFDM IEEE 802.b Long Short Short DSSS-OFDM IEEE 802.g Long Short OFDM Slide 5 Laurent Toutain RES 30

191 Speed versus Distance IEEE 802. Physical Layer g.pdf Slide 6 Laurent Toutain RES 30 Questions IEEE 802. Physical Layer 50 m Mbit/s B C 70 m 5.5 Mbit/s 20 m Mbit/s What is the best strategy to send a 000 Byte frame from to C? Slide 7 Laurent Toutain RES 30