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- 1. Ethernet Networking Technology Overview and Network Design
- 2. Agenda <ul><li>10 Mbit/s Ethernet technology </li></ul>What is a Local Area Network? Overview of network technologies 3 2 1
- 3. Agenda 100 Mbit/s Ethernet technology Switching technology 1000 Mbit/s Ethernet technology 5 4 6
- 4. 10 Mbit/s Ethernet technology What is a Local Area Network? Overview of network technologies 100 Mbit/s Ethernet technology Switching technology 1000 Mbit/s Ethernet technology 3 2 1 5 4 6
- 5. What is a Local Area Network? <ul><li>Definition of a LAN </li></ul><ul><li>Why use a LAN? </li></ul><ul><li>Characteristics of LANs </li></ul><ul><li>LAN Topologies and Structured Cabling </li></ul><ul><li>Repeaters, Bridges and Routers </li></ul><ul><li>Switching and Segmenting networks </li></ul><ul><li>Virtual LANs </li></ul>
- 6. Definition of a LAN <ul><li>A LAN is a system of cabling, equipment and software which allows computers to share and exchange data electronically, using an agreed format (protocol), within a ‘local’ area </li></ul>
- 7. Other types of Area Network <ul><li>WAN - Wide Area Network </li></ul><ul><ul><li>Interconnecting LANs and users over long distances, often on a public network </li></ul></ul><ul><li>MAN - Metropolitan Area Network </li></ul><ul><ul><li>Interconnecting LANs and users within a city area, typically by dedicated fibre optics </li></ul></ul>
- 8. Why use a LAN? <ul><li>An island of information </li></ul>
- 9. Why use a LAN? <ul><li>Users can share data </li></ul><ul><ul><li>Saves time, makes work more efficient </li></ul></ul><ul><li>Connect different computers together </li></ul><ul><ul><li>A LAN can be the common denominator </li></ul></ul><ul><li>Users can share resources (printers, storage) </li></ul><ul><ul><li>Saves money on expensive capital equipment </li></ul></ul><ul><ul><li>Centralised administration </li></ul></ul><ul><li>E-mail, Internet and Multimedia </li></ul><ul><ul><li>Reduces paper documents, better information </li></ul></ul>
- 10. LAN Characteristics <ul><li>How are LANs characterised? </li></ul><ul><ul><li>By speed (bandwidth) </li></ul></ul><ul><ul><li>By topology </li></ul></ul><ul><ul><li>By special features </li></ul></ul><ul><ul><li>By their target application </li></ul></ul><ul><li>LAN technologies are optimised for certain application areas </li></ul>
- 11. Network Topologies BUS Nodes are all connected to the same circuit RING Nodes are connected in a daisy chain
- 12. Network Access Methods Token Passing Nodes wait their turn to use the network Contention Nodes try to use the network at any time T
- 13. Network Wiring Topologies Bus Ring STAR wiring topology Nodes are physically wired to a central point
- 14. Structured Cabling <ul><li>Uses UTP for floor wiring </li></ul><ul><li>Uses Fibre for backbone connections </li></ul><ul><li>Many more wires installed than users - flood wiring </li></ul><ul><li>All cables star-wired from central points </li></ul><ul><li>Flexible, resilient, future proof, easy moves </li></ul>
- 15. Connecting nodes to a LAN Network Operating System (NOS) Software Network Interface Card (NIC) Cable Communication by an agreed Protocol Network Hub To other hosts on the network MAC Address “ DTE”
- 16. Network Protocols <ul><li>Protocols are the “language” used on a network </li></ul><ul><li>The network just sends and receives packets of data, while the protocol ensures that the right data is delivered to the right place </li></ul><ul><li>Using common protocols allows computers from different manufacturers to exchange data </li></ul>
- 17. Protocols defined... A protocol is a common system where both parties acknowledge the same rules governing communication.
- 18. Interconnecting Networks <ul><li>Three ways to join network segments together: Repeaters , Bridges and Routers </li></ul><ul><li>Repeaters extend physical networks </li></ul><ul><li>Bridges link networks of the same type together </li></ul><ul><li>Routers connect networks of different types together </li></ul>
- 19. Connecting network segments with Repeaters All network traffic visible to all the nodes on the network Repeater forwards all activity Repeater
- 20. Connecting network segments with Bridges Local Traffic stays on local segment Local Traffic stays on local segment Bridge only forwards traffic intended for the other network Bridge
- 21. Connecting networks together with Routers Router Router Local Traffic stays on local segments Routers transfer protocol-specific traffic (e.g. IP, IPX) between different network types, e.g. across a WAN X.25, Frame Relay, ISDN etc. Local Network Remote Network WAN
- 22. Summary <ul><li>Networks allow computers to share data quickly and cheaply </li></ul><ul><li>Networks are a combination of hardware and software </li></ul><ul><li>Network technologies can be shared or switched, or a mix of both </li></ul>
- 23. 10 Mbit/s Ethernet technology What is a Local Area Network? 100 Mbit/s Ethernet technology Switching technology 1000 Mbit/s Ethernet technology Overview of network technologies 3 5 4 6 2 1
- 24. Overview of Network technologies <ul><li>Ethernet: 10 Mbit/s </li></ul><ul><li>Fast Ethernet: 100 Mbit/s </li></ul><ul><li>Gigabit Ethernet: 1000 Mbit/s </li></ul><ul><li>IBM Token Ring: 4 and 16 Mbit/s </li></ul><ul><li>100VG-AnyLAN: 100 Mbit/s </li></ul><ul><li>FDDI: 100 Mbit/s </li></ul><ul><li>ATM: 25, 155 and 622 Mbit/s </li></ul>
- 25. Ethernet Technologies <ul><li>10 Mbit/s Ethernet </li></ul><ul><ul><li>One of the oldest network technologies, and still the most popular </li></ul></ul><ul><li>Fast Ethernet (100 Mbit/s) </li></ul><ul><ul><li>Upgrade route from 10 Mbit/s, providing higher performance </li></ul></ul><ul><li>Gigabit Ethernet (1000 Mbit/s) </li></ul><ul><ul><li>The next generation for servers and backbones, providing very high throughput </li></ul></ul>
- 26. Gigabit Ethernet <ul><li>Promoted by the Gigabit Ethernet Alliance </li></ul><ul><li>Being standardised in IEEE 802.3z, due in 1998 </li></ul><ul><li>Uses same CMSA/CD technology as Ethernet, running at 1000 Mbit/s </li></ul><ul><li>Gigabit Ethernet on copper cabling is a special problem </li></ul><ul><li>High-performance backbone technology </li></ul>
- 27. Network Technologies: Summary <ul><li>Networking technologies can be classified by their access mechanism </li></ul><ul><li>Contention-based technologies are less efficient than other solutions, but the overall cost of ownership is lower </li></ul><ul><li>Ethernet covers all parts of a LAN from desktop to backbone </li></ul>
- 28. 10 Mbit/s Ethernet technology What is a Local Area Network? Overview of network technologies 100 Mbit/s Ethernet technology Switching technology 1000 Mbit/s Ethernet technology 3 2 1 4 5 6
- 29. 10 Mbit/s Ethernet <ul><li>Origins of 10 Mbit/s Ethernet </li></ul><ul><li>How Ethernet works </li></ul><ul><ul><li>CSMA/CD operation </li></ul></ul><ul><ul><li>Full and Half Duplex modes </li></ul></ul><ul><ul><li>Ethernet frames </li></ul></ul><ul><li>Components of an Ethernet LAN </li></ul><ul><ul><li>Software and Network Interface Card </li></ul></ul><ul><ul><li>Transceivers and Cabling </li></ul></ul><ul><ul><li>Repeaters and Hubs </li></ul></ul><ul><ul><li>Switches </li></ul></ul>
- 30. Origins of 10 Mbit/s Ethernet <ul><li>Original system design by DEC, Intel, and Xerox (hence DIX Ethernet) </li></ul><ul><li>Designed in 1970’s, first specifications 1980 </li></ul><ul><li>Ethernet type II adopted as IEEE 802.3 10BASE-X, first published in 1985 </li></ul>
- 31. How Ethernet works 1 <ul><li>All transmission is at 10 million bits per second (0’s or 1’s) </li></ul><ul><li>Users are connected to common cable (media) </li></ul><ul><li>Access to the media is by a simple set of rules known as Carrier Sense Multiple Access / Collision Detect (CSMA/CD). </li></ul><ul><ul><li>Listen for silence on cable (CS) </li></ul></ul><ul><ul><li>Transmit data without waiting your turn (MA) </li></ul></ul><ul><ul><li>If you hear someone else talking - stop sending, and wait for a random time before trying again (CD) </li></ul></ul>
- 32. How Ethernet Works 2 1. Send when the network is quiet 2. Collision is detected if another station sends 3. Both stations wait for a random time 4. Re-send again when the network is quiet
- 33. Full and Half Duplex 1 <ul><li>Normal Ethernet only allows one frame on the cable at a time (Half Duplex) </li></ul><ul><li>UTP and fibre optics use separate circuits for Transmit and Receive </li></ul><ul><li>Full Duplex allows frames to be sent and received at the same time over a point-to-point link </li></ul><ul><li>Both ends must support Full Duplex </li></ul><ul><li>Repeaters cannot support full duplex </li></ul>
- 34. Full and Half Duplex 2 Half Duplex Operation Transmit only - OK Receive only - OK Transmit and Receive = Collision Full Duplex Operation Transmit and Receive at same time on separate circuits - OK
- 35. How Data is Transferred <ul><li>All data is transferred in ‘packets’ </li></ul><ul><li>A packet of data has addressing details at the start, and error checking data at the end. This is known as a ‘ frame ’ </li></ul><ul><li>Moving data in small pieces gives everyone an equal chance to get their data through </li></ul><ul><li>Smaller packets are more likely to be delivered without errors </li></ul>
- 36. The Ethernet Frame <ul><li>Preamble allows timing alignment </li></ul><ul><li>Start Of Frame delimiter indicates start of frame </li></ul><ul><li>CRC (Cyclic Redundancy Check) is a checksum to ensure the frame was received OK </li></ul><ul><li>Total frame length varies from 64 to 1,518 bytes (after SOF delimiter) </li></ul>Preamble CRC (checksum) Data 46 - 1500 Bytes Source MAC Address Destination MAC Address SOF delimiter Type/length 6 bytes 6 Bytes 2 4
- 37. Components of an Ethernet LAN Shared cable External Transceiver Drop cable (external XCVR) Network Interface card Software Point-to-point link cable (integral XCVR) Hub: Repeater, Bridge, Switch or Router
- 38. Network Interface Card <ul><li>The Network Interface Card (NIC) contains: </li></ul><ul><ul><li>the connection to the transceiver, or a built-in transceiver </li></ul></ul><ul><ul><li>circuitry for generating frames and accessing the network </li></ul></ul><ul><ul><li>the physical MAC address </li></ul></ul><ul><ul><li>a software interface to the protocol software in the host </li></ul></ul>
- 39. Transceivers <ul><li>Transceivers provide the electrical and physical connection between the Adapter and the shared network cable </li></ul>XCVR <ul><li>This type of transceiver is not used much today as most NICs have this function built in. </li></ul>AUI drop cable Thick Ethernet Cable
- 40. Current Transceiver Uses <ul><li>Connecting standard hub/router/switch AUI interfaces to cable media </li></ul><ul><li>Connecting ‘legacy’ cards to newer cabling </li></ul>
- 41. Ethernet Cable Options <ul><li>The cable provides physical connection between the adapter cards. Multiple cable types are available. </li></ul>10Base5 10Base2 10BaseT 100BaseTX 10BaseFL 100BaseFX Thick Ethernet Thin Ethernet Twisted Pair (UTP) Fibre Optic BNC RJ45 SMA* Screw type ST Bayonet SC Dual Mini AUI connection via Vampire Tap Ethernet Cable Connector Usage Half-duplex shared cable Full-Duplex Point-to-point link Half-duplex shared cable Full-Duplex Point-to-point link * SMA now obsolete, no new equipment manufactured to support this standard
- 42. Ethernet Cable Options 10BaseFL 100BaseFX Fibre Optic Lucent LC New sub-miniature SC 3M Volition VF-45 Fibre version of RJ-45 AMP MT-RJ Fibre version of RJ-45 New fibre connectors becoming widespread during 1999/2000. Full-Duplex Point-to-point link
- 43. Cable Distances and Taps 10BASE5 = 10 Mbps Baseband 500 metres length (100 taps) 10BASE2 = 10 Mbps Baseband 200 (185)metres (30 Taps) 10BASE-T =10 Mbps Baseband (100 metres) Twisted pair (single Tap)
- 44. 10 Mbit/s Repeaters <ul><li>10 Mbit/s Repeaters allow more users AND more distance </li></ul><ul><li>Repeaters do a number of tasks: </li></ul><ul><ul><li>restore the signal levels (amplify signal) </li></ul></ul><ul><ul><li>ensure that collisions are recognised, and stop anyone else transmitting until it is safe </li></ul></ul>
- 45. <ul><li>Si può vedere l’hub come un multiport repeater. </li></ul>Four Repeater Roule <ul><li>Come nel coassiale esiste la regola dei 4 repeater negli hub a 10Mb/s </li></ul>Hub Hub Hub Hub
- 46. Ethernet 5-4-3 Rule <ul><li>Maximum of five segments </li></ul><ul><li>Maximum of four repeaters between any two nodes </li></ul><ul><li>Maximum of three multi-node segments </li></ul>Repeater Repeater Repeater Repeater Multinode Segment Multinode Segment Multinode Segment Link Segment Link Segment
- 47. Why are there Limits? <ul><li>Transmission from a user down the network cable takes time . </li></ul><ul><li>All users must see transmission before user has transmitted half of his frame. </li></ul><ul><li>This may need to checked by calculating the Round Trip Delay Time . </li></ul><ul><ul><li>i.e. RT Delay < time for min frame length </li></ul></ul><ul><ul><li>or time for 64 Bytes (512 Bit times) </li></ul></ul><ul><li>The 5-4-3 rule is usually sufficient for 10 Mbit/s Ethernet </li></ul>
- 48. Ethernet Hubs <ul><li>Hubs provide a central connection point for networks </li></ul><ul><li>Commonly used with Structured Cabling Schemes </li></ul>
- 49. Hubs and Management <ul><li>Hubs can be combined to create one big repeater - stackable, chassis based </li></ul><ul><li>Flexible options for integrating all media types </li></ul><ul><li>Management features allow network supervisors to see traffic flow and solve problems fast </li></ul><ul><li>Other advanced features also added </li></ul><ul><ul><li>e.g. security </li></ul></ul>
- 50. 10 Mbit/s Ethernet: Summary <ul><li>Repeater </li></ul><ul><ul><li>copies everything from one segment to another: collisions, fragments, all frames including broadcasts </li></ul></ul><ul><li>Bridges and Switching Hubs </li></ul><ul><ul><li>Selected frames including broadcasts are copied, based on the destination MAC address </li></ul></ul><ul><li>Router </li></ul><ul><ul><li>Copies / converts selected frames based on protocol address </li></ul></ul>
- 51. 10 Mbit/s Ethernet technology What is a Local Area Network? Overview of network technologies 100 Mbit/s Ethernet technology Switching technology 1000 Mbit/s Ethernet technology 3 2 1 4 5 6
- 52. 100 Mbit/s Ethernet <ul><li>Relationship with 10BASE-X </li></ul><ul><li>Media options and technologies </li></ul><ul><li>Repeaters and configuration rules </li></ul><ul><li>Media Independent Interface (MII) </li></ul><ul><li>N-Way Auto-Negotiation </li></ul><ul><li>100BASE-X switching </li></ul>
- 53. 100BASE-X Networks <ul><li>Based on CSMA/CD </li></ul><ul><li>Transmission at 100 Million Bits per second </li></ul><ul><li>Uses same frames as 10 Mb Ethernet </li></ul><ul><ul><li>Whole protocol stack and NOS remain unchanged </li></ul></ul><ul><ul><li>Easy migration from existing systems </li></ul></ul>
- 54. Auto-Negotiation (Nway) <ul><li>Nway auto-negotiation </li></ul><ul><ul><li>Negotiation of a ‘way’ from N options </li></ul></ul><ul><ul><li>Happens between the two ends of a link </li></ul></ul><ul><ul><li>Fastest available ‘way’ is selected </li></ul></ul><ul><ul><li>If only one end has Nway then speed is detected (but not always duplex mode) </li></ul></ul>
- 55. MII - Media Independent Interface <ul><li>MII is a standardised interface between a 100BASE-X transceiver and the connected station (DTE) </li></ul><ul><li>The DTE can control the transceiver function, e.g. full/half duplex & speed </li></ul><ul><li>The transceiver can ‘declare’ its capabilities to the DTE </li></ul>
- 56. 100BASE-X Media Options <ul><li>Cable I EEE 802.3u Standard Pairs Used Distance </li></ul><ul><li>UTP Cat 5 100BASE-TX 2 100m </li></ul><ul><li>UTP Cat 3,4,5 100BASE-T4 4 100m </li></ul><ul><li>Fibre 100BASE-FX 2 fibres 412m* </li></ul><ul><li>Fibre 100BASE-FX 2 fibres 2000 m* * </li></ul><ul><li>* Half Duplex DTE-DTE </li></ul><ul><li>* * Full Duplex DTE-DTE </li></ul>
- 57. 100BASE-X Technologies: TX <ul><li>100BASE-TX </li></ul><ul><ul><li>Uses two twisted pairs </li></ul></ul><ul><ul><li>Same system as 10BASE-T but faster! </li></ul></ul><ul><ul><li>Must have Category 5 cable to run on </li></ul></ul><ul><ul><li>Max distance 100m </li></ul></ul><ul><ul><li>Full or Half duplex possible </li></ul></ul>
- 58. 100BASE-X Technologies: FX <ul><li>100BASE-FX </li></ul><ul><ul><li>Uses two 62.5/125 multimode fibres </li></ul></ul><ul><ul><li>Operates at 1300nm (10BASE-FL operates at 850nm) </li></ul></ul><ul><ul><li>Full duplex is possible but no auto-negotiation </li></ul></ul><ul><ul><li>The maximum link length depends on the configuration of the network </li></ul></ul><ul><ul><ul><li>i.e. it gets shorter if you have a repeater </li></ul></ul></ul>
- 59. 100BASE-X Repeaters <ul><li>Primary use for 100BASE-X repeaters is to add more users </li></ul><ul><li>Otherwise the same functions as 10BASE-X repeater </li></ul>
- 60. 100BASE-X Repeater Classes <ul><li>IEEE 802.3u defines two classes of repeater according to signal delay </li></ul><ul><ul><li>Class I (the worst class!) </li></ul></ul><ul><ul><ul><li>delay of less than 140 bit times </li></ul></ul></ul><ul><ul><li>Class II </li></ul></ul><ul><ul><ul><li>delay of less than 92 bit times </li></ul></ul></ul><ul><li>1 bit time is 1/100,000,000th of a second (10 nanoseconds) </li></ul>
- 61. Basic Configuration Rules <ul><li>Maximum of one Class I repeater in a collision domain </li></ul><ul><li>Maximum of 2 Class II repeaters, but limited distance </li></ul>100m Class I 100m 100m Class II 100m 5m Class II
- 62. Calculating complex configurations <ul><li>As with 10 Mbit/s Ethernet, the Round Trip Delay time must be less than 512 bit times to guarantee collision detection </li></ul><ul><li>The basic rules about repeaters onl y cover the situations in the previous slide, so always calculate anything else </li></ul>
- 63. Calculating the Delay <ul><li>“ Typical bit time delays ” for 100 Mbit/s network components </li></ul>Component Delay per metre Max delay Two TX/FX DTEs 100 Two T4 DTEs 138 One T4 and one TX/FX DTE 127 Cat 3 Cable Segment 1.14 114 (100m) Cat 4 Cable segment 1.14 114 (100m) Cat 5 Cable segment 1.112 111.2 (100m) Shielded Twisted Pair Cable 1.112 111.2 (100m) Fibre Optic Cable 1.0 412 (412m) Class I Repeater 140 Class II Repeater all TX/FX 92 Class II Repeater with any T4 67 AT-MC101 40
- 64. Example Calculation 1 100Mbps Hub 60m Fibre 80m UTP 100m UTP Device Delay (bit times) Two DTEs 100 180m Cat 5 UTP 200 2* Class II Repeaters 184 60m Fibre segment 60 margin 4 TOTAL 548 The above system is outside the limits and will not function correctly 100Mbps Hub
- 65. Example Calculation 2 200m Fibre 100m UTP Device Delay (bit times) Two DTEs 100 100m Cat 5 UTP 111 Class II Repeater 92 200m Fibre segment 200 Margin 4 TOTAL 507 The above system is within the 512 bit time limit so will work OK. 100Mbps Hub
- 66. Switched 100 Mbit/s <ul><li>Similar to switched 10 Mbit/s Ethernet </li></ul><ul><li>Most 100 Mbit/s switches support 10 Mbit/s ports too </li></ul><ul><li>Requires an order of magnitude increase in throughput </li></ul><ul><ul><li>160 Mb/s for 16 port 10Mbps switch </li></ul></ul><ul><ul><li>1.6 Gb/s for 16 port 100Mbps switch </li></ul></ul><ul><li>Key application as backbone switch </li></ul>
- 67. 100 Mbit/s Ethernet: Summary <ul><li>100 Mbit/s and 10 Mbit/s Ethernet use the same CSMA/CD technology and software </li></ul><ul><li>Shared multi-drop cables are not supported </li></ul><ul><li>Round Trip Delay time calculations are essential for network design </li></ul><ul><li>100 Mbit/s can be integrated into a 10 Mbit/s network only with switching technology </li></ul>
- 68. 100 Mbit/s Ethernet: Summary <ul><li>Distances are more restricted so 100Mbps tends to be switch-centric in design. </li></ul>H H H H H H H H H H H S S S S S S S
- 69. 10 Mbit/s Ethernet technology What is a Local Area Network? Overview of network technologies 100 Mbit/s Ethernet technology Switching technology 1000 Mbit/s Ethernet technology 3 2 1 5 4 6
- 70. Switching Technology 1 <ul><ul><li>The maximum bandwidth available on a shared network is limited to the network speed, regardless of the number of nodes </li></ul></ul><ul><ul><li>The maximum traffic that these nodes could generate is more than the network could carry </li></ul></ul><ul><ul><li>Sharing the same media introduces a bottleneck </li></ul></ul>Conversation
- 71. Switching Technology 2 Three simultaneous conversations <ul><ul><li>A Switching Hub at the centre of the network can handle multiple point-to-point conversations at the same time </li></ul></ul><ul><ul><li>The use of the network is more efficient </li></ul></ul>
- 72. Segmenting Networks 1 <ul><li>Very large networks are less efficient, even with switching technology </li></ul><ul><li>It is unusual for all users on a large network to need frequent communications with all other users </li></ul><ul><li>Segmenting a large network into functional groups improves performance and manageability </li></ul>
- 73. Segmenting Networks 2 100% <ul><li>Large networks generate a lot of traffic at the hub in the centre </li></ul><ul><li>The broadcast load is proportional to the square of the number of nodes </li></ul>
- 74. Segmenting Networks 3 Non-broadcast inter-network traffic Broadcast load is quartered 25% 25%
- 75. Switched 10 Mbit/s <ul><li>Switch separates traffic that is sent direct from station to station - Datagrams . </li></ul><ul><li>MAC addresses are learned from incoming frames. </li></ul><ul><li>Frames are only sent out of port where the destination address resides. </li></ul><ul><li>Broadcast frames are forwarded to all ports, to the MAC address FF-FF-FF-FF-FF-FF </li></ul>
- 76. Switching Techniques 1 <ul><li>Store and forward switching </li></ul><ul><ul><li>Whole frame buffered in memory, then sent </li></ul></ul>Preamble CRC Data 46 - 1500 Bytes Source Address Destination Address SOF delimiter Type/length 6 bytes 6 Bytes 2 4 Cut-through switching Forwarding started just after the destination MAC address arrives
- 77. Switching Techniques 2 <ul><li>Fragment-free cut-through </li></ul><ul><ul><li>frame forwarded after 64 Bytes </li></ul></ul>Preamble CRC Data 46 - 1500 Bytes Source Address Destination Address SOF delimiter Type/length 6 bytes 6 Bytes 2 4
- 78. Segment Switching <ul><li>Switch is used to ‘feed’ hubs. </li></ul><ul><li>Small groups of users share 10 Mbit/s segments from switch e.g. Turbo Stack </li></ul><ul><li>Reasonable MAC address capacity required </li></ul><ul><li>Extra features </li></ul>hub hub hub hub switch
- 79. Workgroup Switching <ul><li>Small switch provides dedicated switch ports to individual ‘power’ users. </li></ul><ul><li>Low MAC address capacity required </li></ul><ul><li>Low cost per port </li></ul>Switch
- 80. Backbone/Enterprise Switching <ul><li>Large, high capacity switch used to connect backbone segments of large networks. </li></ul><ul><li>Huge MAC address capacity required </li></ul><ul><li>Modular design - chassis based </li></ul><ul><li>Very high throughput capability </li></ul>
- 81. Bandwidth Switching <ul><li>Switches can be used to connect segments of different speeds, e.g. 10 and 100 Mbit/s </li></ul><ul><li>The 10 Mbit/s segments can be ‘multiplexed’ onto the 100 Mbit/s segment </li></ul><ul><li>The switch must use Store-and-Forward to change the bandwidth </li></ul>Switch 100 Mbit/s 10 Mbit/s
- 82. Rules for using Switches <ul><li>Switch is essentially a bridge , so start any repeater counts again. </li></ul><ul><li>Too many switches in network could cause delay. IEE 802.3 says max 7 bridges. (This is an arbitrary number based on Token Ring limitations) </li></ul><ul><li>Keep number of hops to main servers low. </li></ul>
- 83. Hub Dual-Speed Autosensing <ul><li>Reti miste: con utenti a 10 e 100 mbps </li></ul><ul><li>Configurazione Stackable: facilmente espandibile </li></ul><ul><li>Percorso di migrazione da Ethernet a Fast Ethernet </li></ul>Sw 10 Mbps 100 Mbps … . Switch Module
- 84. Virtual LANs (VLANs) 1 <ul><li>A company-wide network may not be the right solution, due to high traffic and security issues </li></ul><ul><li>The user may want to divide their big network into smaller sections </li></ul><ul><li>But, flexibility is also needed as people move around </li></ul><ul><li>A “Virtual Network” solves this problem </li></ul>
- 85. Virtual LANs 2 Virtual Network Switch VLAN “A” VLAN “B” VLAN “C”
- 86. 10 Mbit/s Ethernet technology What is a Local Area Network? Overview of network technologies 100 Mbit/s Ethernet technology 1000 Mbit/s Ethernet technology Switching technology 3 2 1 6 4 5
- 87. The pressure on networks today <ul><li>Traffic Flows have changed </li></ul><ul><ul><li>Used to be 80% local, 20% backbone </li></ul></ul><ul><ul><li>Now 20% local and 80% backbone </li></ul></ul><ul><li>User requirements have changed </li></ul><ul><ul><li>Word processing was dominant </li></ul></ul><ul><ul><li>Now Internet use is the dominant application </li></ul></ul><ul><li>Application useage has changed </li></ul><ul><ul><li>It only takes 8 bytes to send the word ‘airplane’ </li></ul></ul><ul><ul><li>It takes 80,000 bytes to send an image of an airplane </li></ul></ul><ul><ul><li>It takes 8,000,000 to send a video clip of an airplane </li></ul></ul>
- 88. 1000Mbps Gigabit Systems <ul><li>Same frame formats and protocols as 10/100 Ethernet </li></ul><ul><li>Same Full/Half Duplex mode </li></ul><ul><li>Same management (SNMP/RMON) systems </li></ul><ul><li>Primarily a fibre based technology </li></ul><ul><li>Standardised by IEEE as 802.3z </li></ul>
- 89. 1000BaseX Cable Options <ul><li>Standard Media Range </li></ul><ul><li>1000BaseLX Single Mode Fibre 3km+ </li></ul><ul><li>1000BaseLX Multi-Mode Fibre 550m </li></ul><ul><li>1000BaseSX Multi-Mode 300m </li></ul><ul><li>(most common type) </li></ul><ul><li>1000BaseCX Twinaxial Cable 25m </li></ul><ul><li>1000BaseT UTP 100m </li></ul>
- 90. 1000BaseX Media <ul><li>The basic media carrier for 100Base is the GBIC </li></ul><ul><li>GBICs are a media independent device (similar to transceiver in 10Base) </li></ul><ul><li>Provide plug in options for SX or LX fibre </li></ul>
- 91. 1000BaseX Hardware <ul><li>Switches and Routers for Networks </li></ul><ul><li>Two primary types of switch </li></ul><ul><ul><li>Core Switches…… Multiple Gigabit ports </li></ul></ul><ul><ul><li>Edge Switches…… Multiple 10/100 ports 1 or 2 Gigabit ports </li></ul></ul>
- 92. A new layer of performance 100Base Hub 10Base Hub 10Base Hub 10Base Switch 100Base Switch 1000Base Edge 100Base Hub 10Base Hub 10Base Hub 10Base Switch 100Base Switch 1000Base Edge 1000Base Core Performance
- 93. Thank you for your attention

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