Switches and Routers.ppt

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Switches and Routers.ppt

  1. 1. CHAPTER Network Hardware
  2. 2. Chapter Objectives <ul><li>Describe the important basic network hardware and the internetworking hardware </li></ul><ul><li>Discuss the desired characteristics of a server and a workstation </li></ul><ul><li>Present different switching technologies </li></ul><ul><li>Examine the routing process with the help of an example </li></ul>
  3. 3. Classification of Basic Network Hardware Components <ul><li>Network Interface Cards (NICs) </li></ul><ul><li>Cables </li></ul><ul><li>Connectors </li></ul><ul><li>Servers </li></ul><ul><li>Workstations </li></ul>
  4. 4. Classification of Internetworking Hardware Components <ul><li>Line drivers or repeaters </li></ul><ul><li>Transceivers </li></ul><ul><li>Intelligent hubs </li></ul><ul><li>Bridges </li></ul><ul><li>Switches </li></ul><ul><li>Routers </li></ul><ul><li>Gateways </li></ul>
  5. 5. Chapter Modules <ul><li>Network interface cards </li></ul><ul><li>Network connectors and hubs </li></ul><ul><li>Server and workstation hardware </li></ul><ul><li>Repeater </li></ul><ul><li>Bridge </li></ul><ul><li>Switch </li></ul>Continued..
  6. 6. Continuation of Chapter Modules <ul><li>Switching technology </li></ul><ul><li>Router </li></ul><ul><li>Gateway </li></ul>
  7. 7. END OF CHAPTER INTRODUCTION
  8. 8. MODULE Network Interface Cards (NICs)
  9. 9. Network Interface Card Types <ul><li>10BaseT cards </li></ul><ul><ul><li>Physical star networks </li></ul></ul><ul><ul><li>10 Mbps speed </li></ul></ul><ul><ul><li>Ethernet standard </li></ul></ul><ul><ul><li>Twisted pair wiring </li></ul></ul><ul><li>10base2 cards </li></ul><ul><ul><li>Physical bus networks </li></ul></ul><ul><ul><li>10 Mbps speed </li></ul></ul><ul><ul><li>Ethernet standard </li></ul></ul><ul><ul><li>Thin coaxial wiring </li></ul></ul>
  10. 10. Continuation of NIC Types <ul><li>10Base5 </li></ul><ul><ul><li>10 Mbps speed </li></ul></ul><ul><ul><li>Ethernet standard </li></ul></ul><ul><ul><li>Thick coaxial wiring </li></ul></ul><ul><li>100BaseTX </li></ul><ul><ul><li>100 Mbps speed </li></ul></ul><ul><ul><li>Fast Ethernet standard </li></ul></ul><ul><ul><li>Twisted pair </li></ul></ul><ul><ul><ul><li>Higher quality Category 5 wires are recommended </li></ul></ul></ul>
  11. 11. Token Ring Cards <ul><li>Token ring network cards </li></ul><ul><li>Earlier token ring cards </li></ul><ul><ul><li>4 Mbps </li></ul></ul><ul><li>Newer token ring cards </li></ul><ul><ul><li>16 Mbps </li></ul></ul>
  12. 12. Bus Types for NICs <ul><li>Card connector types </li></ul><ul><ul><li>Newer PCI bus </li></ul></ul><ul><ul><li>Older ISA, VESA and EISA bus types </li></ul></ul><ul><li>ISA bus width </li></ul><ul><ul><li>16-bit </li></ul></ul><ul><li>PCI bus width </li></ul><ul><ul><li>Usually 32-bit </li></ul></ul><ul><ul><li>Supports 64-bit as well </li></ul></ul><ul><ul><ul><li>Used in high-powered network servers </li></ul></ul></ul>
  13. 13. Cable Connections for NICs <ul><li>BNC barrel connector </li></ul><ul><ul><li>Thin coaxial </li></ul></ul><ul><li>RJ 45 </li></ul><ul><ul><li>Twisted pair </li></ul></ul>
  14. 14. AUI and Combo Cable Connections for NICs <ul><li>AUI Possibilities </li></ul><ul><ul><li>Designed for a thick coaxial cable </li></ul></ul><ul><ul><li>Designed for a token ring network </li></ul></ul><ul><ul><li>Provided for connecting a transceiver </li></ul></ul><ul><li>Combo Cards </li></ul><ul><ul><li>Consisting of different ports </li></ul></ul><ul><ul><li>BNC, RJ-45, AUI </li></ul></ul>
  15. 15. Possible Combo Card Connections <ul><li>Thin coaxial cables (BNC) </li></ul><ul><li>Twisted pair wires (RJ-45) </li></ul><ul><li>Thick coaxial cables (AUI) </li></ul>
  16. 16. Description of an Actual NIC <ul><li>10BaseT, PCI card </li></ul><ul><ul><li>10 = speed in Mbps </li></ul></ul><ul><ul><li>Base =Ethernet </li></ul></ul><ul><ul><li>T = Twisted pair </li></ul></ul><ul><ul><li>32-bit = bus width </li></ul></ul><ul><ul><li>PCI = bus technology </li></ul></ul>
  17. 17. END OF MODULE
  18. 18. MODULE Sample Network Interface Cards
  19. 19. Example of a 10Base2 Card BNC Source: Black Box
  20. 20. Example of a 10BaseT Card RJ 45 ISA Source: Black Box
  21. 21. Example of a Combo Card Combo Source: Black Box RJ 45 BNC
  22. 22. END OF MODULE
  23. 23. MODULE Network Connectors and Hubs
  24. 24. Simple Connectors <ul><li>T connectors </li></ul><ul><ul><li>An interface between the NIC and the cables </li></ul></ul><ul><li>Terminators </li></ul><ul><ul><li>Used at both ends of a bus network </li></ul></ul>Terminator T Connector
  25. 25. Example of T-Connector and Terminator T Connector Terminator Source: Black Box
  26. 26. Connectors : Hubs <ul><li>Types </li></ul><ul><ul><li>Active hub </li></ul></ul><ul><ul><li>Passive hub </li></ul></ul><ul><li>Passive hubs </li></ul><ul><ul><li>Simply provides the physical and the electrical connection for the network </li></ul></ul><ul><li>Active hubs </li></ul><ul><ul><li>Has built-in intelligence </li></ul></ul><ul><ul><li>Some are manageable hubs </li></ul></ul>
  27. 27. Connectors : Passive Hub MAU WS WS Hub Connecting A Token-ring Network WS
  28. 28. An Active Hub Backbone Manageable Hub Remote Workstation WS WS WS Remote Monitor Active Hub
  29. 29. Hub Management Software <ul><li>Sophisticated </li></ul><ul><li>Monitor the network traffic through each of the ports </li></ul><ul><li>Becoming popular </li></ul><ul><li>Standardized protocol for remote management exists </li></ul><ul><ul><li>SNMP (Simple Network Management Protocol) </li></ul></ul>
  30. 30. Example of a Hub Used in Ring Network Source: Black Box
  31. 31. Example of Hubs Used in the Star Network Stackable Hubs Source: Black Box
  32. 32. END OF MODULE
  33. 33. MODULE Server and Workstation Hardware
  34. 34. Module Objectives <ul><li>Give an overview of the different types of the server hardware </li></ul><ul><li>Discuss the desired characteristics of a server </li></ul><ul><li>Provide a specification for a workstation </li></ul>
  35. 35. Servers <ul><li>Backbone of a network </li></ul><ul><li>Types </li></ul><ul><ul><li>Powerful micros </li></ul></ul><ul><ul><li>Servers </li></ul></ul><ul><ul><li>Super-servers </li></ul></ul><ul><ul><li>Sometimes mini-computers are used as servers </li></ul></ul><ul><li>In a client-server, the server also acts as an engine of database execution </li></ul><ul><li>In general, it is used for the sharing of stored data and application </li></ul>
  36. 36. Desired Characteristics of Server: Processor and Storage Requirement <ul><li>Powerful processor </li></ul><ul><ul><li>Latest Pentium Processor </li></ul></ul><ul><ul><li>Multiple processors, if appropriate </li></ul></ul><ul><li>Large storage space </li></ul><ul><ul><li>Several gigabytes at a minimum </li></ul></ul><ul><ul><li>Actual requirement will vary LAN size </li></ul></ul><ul><li>Fast disk access speed </li></ul><ul><ul><li>Less than 10 ms </li></ul></ul>
  37. 37. Desired Characteristics of a Server: CD-ROM <ul><li>Fast CD-ROM drives </li></ul><ul><li>CD-ROM towers are often preferred </li></ul>
  38. 38. Desired Characteristics of Server: Storage Technology <ul><li>Better hard disk technology </li></ul><ul><ul><li>SCSI </li></ul></ul><ul><ul><ul><li>Fast access </li></ul></ul></ul><ul><ul><ul><li>Daisy chaining of devices </li></ul></ul></ul><ul><ul><li>Latest SCSI technology is required </li></ul></ul><ul><li>Possible consideration given to fiber-channel in the future </li></ul>
  39. 39. Desired Characteristics of Server: Bus and Memory Technologies <ul><li>Better bus technology </li></ul><ul><ul><li>PCI </li></ul></ul><ul><li>Memory </li></ul><ul><ul><li>In excess of 128 Mbytes </li></ul></ul><ul><ul><li>SDRAM or similar memory technology functioning at 10 nanoseconds or less </li></ul></ul><ul><ul><li>The 128-pin SDRAM is also known as the DIMM chips as opposed to the 72-pin SIMM chips </li></ul></ul>
  40. 40. Desired Characteristics of Server: Reliability <ul><li>Good back-up facilities </li></ul><ul><ul><li>Back-up tape </li></ul></ul><ul><li>Uniterruptible Power Supply (UPS) </li></ul>
  41. 41. Fault Tolerant Feature for Servers <ul><li>RAID storage technology </li></ul><ul><ul><li>A system based on multiple disk </li></ul></ul><ul><ul><li>Hot-swappable disks </li></ul></ul><ul><li>Redundant power supply </li></ul><ul><ul><li>Hot-swappable power supply </li></ul></ul>
  42. 42. Workstation <ul><li>Most applications are executed at the workstation </li></ul><ul><li>Therefore, it must be powerful in terms of the processor and the memory </li></ul><ul><li>As a rule of thumb, the workstation must be as powerful as it were to be used as a standalone unit to run the applications </li></ul>
  43. 43. Workstation Processor and Memory <ul><li>Powerful processor </li></ul><ul><ul><li>Pentium class processor </li></ul></ul><ul><li>Adequate memory </li></ul><ul><ul><li>32 Mbytes or more </li></ul></ul><ul><ul><li>DIMM preferred although fast EDO SIMM may also be used </li></ul></ul>
  44. 44. Workstation Storage and Compatibility <ul><li>Sufficient storage </li></ul><ul><ul><li>Storage in gigabytes </li></ul></ul><ul><ul><li>Important in a client-server environment </li></ul></ul><ul><ul><li>Front-end tools are stored on the workstation </li></ul></ul><ul><li>Speed of storage </li></ul><ul><ul><li>Ultra DMA or SCSI preferred </li></ul></ul><ul><ul><li>EIDE may also be used </li></ul></ul><ul><li>Hardware components with appropriate drivers for the client operating system </li></ul>
  45. 45. Reliability <ul><li>Power surge protector </li></ul><ul><li>Uninterruptible Power Supply (UPS), for critical applications </li></ul>
  46. 46. END OF MODULE
  47. 47. MODULE Repeater
  48. 48. An Overview of Repeaters <ul><li>Used for extending the physical span of a network </li></ul><ul><ul><li>An example is the extension of the distance between a hub and a node </li></ul></ul><ul><li>Span is often limited by design considerations </li></ul><ul><li>10base5 </li></ul><ul><ul><li>The span is limited to 500 meters </li></ul></ul>
  49. 49. A Repeater Connection Expanding the Span of the Network Source: Black Box
  50. 50. Another Example of Repeater Connection Extending the distance between the backbone and the nodes. Source: Black Box
  51. 51. Operations of a Repeater Within the ISO OSI Model <ul><li>Operates at the lower level of the ISO OSI model </li></ul><ul><ul><li>Physical layer </li></ul></ul>Medium Physical Layer Repeater Medium Physical Layer
  52. 52. Other Devices Used for Extending the Span of a Network <ul><li>Line Drivers </li></ul><ul><li>Short-Haul Modems </li></ul>
  53. 53. END OF MODULE
  54. 54. MODULE Bridge
  55. 55. An Overview of a Bridge <ul><li>A device used for connecting two LANs operating under the same protocol </li></ul><ul><li>Currently, the term bridge is loosely being used to describe different interconnecting devices </li></ul><ul><ul><li>Used now for connecting LANs operating under different protocols as well </li></ul></ul>
  56. 56. Purpose of a Bridge <ul><li>Facilitate the movement of data packet from one network segment to another </li></ul><ul><li>Not a sophisticated internetworking device </li></ul><ul><li>Bridge does not perform the routing of information to different segments of a network </li></ul><ul><li>Connects two network segments and not multiple network segments </li></ul>
  57. 57. Bridge : ISO-OSI Layer of Operation Bridge X Medium X Medium Physical Layer Physical Layer Data Link Layer Data Link Layer A simple bridge operates at the second layer of the ISO model.
  58. 58. Practical Bridge Implementations <ul><li>Local Bridge </li></ul><ul><li>Remote Bridge </li></ul>
  59. 59. Local and Remote Bridges <ul><li>Local bridge </li></ul><ul><ul><li>Connects two different LANs located locally </li></ul></ul><ul><li>Remote bridge </li></ul><ul><ul><li>Connects LAN segments that are geographically apart </li></ul></ul><ul><ul><li>An example is a device that provide dial-up access to a LAN </li></ul></ul>
  60. 60. A Practical Bridge Example Source: Black Box
  61. 61. END OF MODULE
  62. 62. MODULE Switch
  63. 63. Switch Definition and Purpose <ul><li>A switch is defined as a device that allows a LAN to be segmented </li></ul><ul><ul><li>The segments will operate under the same protocol </li></ul></ul>
  64. 64. Difference Between a Switch and a Bridge <ul><li>A switch focuses on segmenting a LAN </li></ul><ul><li>A bridge is concerned with linking two network segments that operate under different protocols </li></ul>
  65. 65. Purpose of a Switch <ul><li>Improve the network performance and reliability </li></ul><ul><li>Better manage the network in general </li></ul>
  66. 66. Performance Improvement in Segmented Networks <ul><li>Performance is improved especially in the case of a bus network </li></ul><ul><li>Multiple bus paths are now available for communication </li></ul><ul><li>Each segment can engage in simultaneous communication within itself </li></ul><ul><li>Easier to isolate a problem to a segment </li></ul><ul><ul><li>Thus, better manage the entire network </li></ul></ul>
  67. 67. Network Reliability <ul><li>When one segment does not function, the other segments can continue to function </li></ul><ul><ul><li>Offers better reliability to at least part of the function </li></ul></ul>
  68. 68. Switches in Ethernet and Token Ring LANs <ul><li>Switches were originally designed for segmenting Ethernet LANs </li></ul><ul><ul><li>Used extensively in configuring large Ethernet bus LANs </li></ul></ul><ul><ul><ul><li>Physically the network configured would still largely remain based on the star topology </li></ul></ul></ul><ul><li>Switches are now available for token ring networks as well </li></ul>
  69. 69. Use of Switches in Linking LAN Segments Switch Hub Hub WS Server WS Server Segment 1 Segment 2 Crossover Traffic
  70. 70. Using A Switch to Link Bus LAN Segments Switch Segment 1 Segment 2
  71. 71. Use of Switches in Internetworking <ul><li>Because the typical inter-networking connection involves multiple segments, the use of a switch is more common than the use of a bridge </li></ul>
  72. 72. Use of Switches for Higher Bandwidth WS 100 MBps Switch WS WS WS Each port in theory has a bandwidth of 100 Mbps.
  73. 73. END OF MODULE
  74. 74. MODULE Switching Technology
  75. 75. Module Objectives <ul><li>Explain the basic operation of a switch </li></ul><ul><li>List the switching technologies and describe their operation </li></ul><ul><ul><li>Cut-through and store-and-forward technologies </li></ul></ul>
  76. 76. The Basic Operation of Switches <ul><li>A data packet is analyzed </li></ul><ul><li>Receiver’s addresses is checked </li></ul><ul><li>If it indicates the receiver to be in the same segment, the packet is dropped </li></ul><ul><li>If it indicates the receiver to be in a different segment, the packet is forwarded to a different segment </li></ul>Receiver’s Address Sender’s Address Data
  77. 77. Switching Technologies <ul><li>There are two major types of switching technologies </li></ul><ul><ul><li>Cut-through </li></ul></ul><ul><ul><li>Store-and-forward </li></ul></ul>
  78. 78. Cut-Through Technology <ul><li>Reads only part of the packet </li></ul><ul><ul><li>The addresses header </li></ul></ul><ul><ul><li>Packet is forwarded accordingly </li></ul></ul><ul><li>Bad packets are not filtered </li></ul>
  79. 79. Store-and-Forward Technology <ul><li>Entire packet is processed </li></ul><ul><li>Packets are filtered </li></ul><ul><ul><li>Bad packets are filtered </li></ul></ul>
  80. 80. Switching Technology Comparison Header Sender’s Add Receivers Add Data Cut-through Store-and-forward
  81. 81. Switching Technology Operation at the ISO Layer <ul><li>In each of the two cases of switching technologies no protocol conversion takes place </li></ul><ul><li>Forwarding and filtering are done at the MAC layer </li></ul>
  82. 82. END OF MODULE
  83. 83. MODULE Routers
  84. 84. The Purpose of a Router <ul><li>Connect LANs operating under different protocols </li></ul><ul><li>The LANs connected are better known as sub-networks instead of network segments </li></ul><ul><ul><li>The term segments is nevertheless used in practice </li></ul></ul>
  85. 85. Router Characteristics <ul><li>A router true internetworking device </li></ul><ul><ul><li>Connects different sub-networks together </li></ul></ul><ul><li>Establishes a logical path of communication between the sub-networks </li></ul><ul><li>Contributes to the modular construction of a network </li></ul><ul><ul><li>Network itself is better managed </li></ul></ul><ul><ul><li>Network resources are better utilized </li></ul></ul>
  86. 86. Internetworking with a Router IEEE 802.3 Sub-network IEEE 802.5 Sub-network PC-NFS Sub-network Router
  87. 87. Routers, Switches and Hubs in Perspective Switch Switch Hub Hub S WS WS WS Router Hub S WS Hub WS S Hub WS WS Hub WS S Sub-network 1 Sub-network 2 Backbone
  88. 88. Difference Between Routers, Switches and Hubs <ul><li>Hubs </li></ul><ul><ul><li>Simply provides the mechanical and electrical connections between the nodes </li></ul></ul><ul><li>Switches </li></ul><ul><ul><li>Examine the data packet for the destination address </li></ul></ul><ul><ul><li>Do not alter the data packets </li></ul></ul><ul><li>Routers </li></ul><ul><ul><li>Examine and alter the data packets </li></ul></ul><ul><ul><li>Perform protocol conversion </li></ul></ul>
  89. 89. Router Requirements <ul><li>Requires more processing power compared to switches and bridges </li></ul><ul><li>Operations fall within the network layer of the ISO-OSI communication model </li></ul>
  90. 90. Router : Network Layer Interface X MEDIUM X MEDIUM PHYSICAL LAYER PHYSICAL LAYER DATA LINK LAYER DATA LINK LAYER NETWORK LAYER ROUTER NETWORK LAYER
  91. 91. Devices and Layers PHYSICAL LAYER DATA LINK LAYER NETWORK LAYER Switches Routers Repeaters Switches Layer 1 Layer 2 Layer 3
  92. 92. A Practical Router Example Router Router Router Router Router Source: Black Box
  93. 93. END OF MODULE
  94. 94. MODULE Gateway
  95. 96. An Introduction to Gateways <ul><li>Gateways are comprehensive internetworking devices </li></ul><ul><li>They can be computers themselves </li></ul>
  96. 97. Gateways in the Past <ul><li>Very popular </li></ul><ul><li>They were the only devices that could be used for internetworking </li></ul><ul><li>Computers of the past were not designed with network connections in mind </li></ul><ul><ul><li>Interconnection of different computer systems has to be managed and driven by an advanced device such as a gateway </li></ul></ul>
  97. 98. The Present Scenario <ul><li>Computers are now designed with due consideration given to network connections </li></ul><ul><li>Larger networks could today be configured using internetworking devices </li></ul><ul><ul><li>Routers, switches, hubs etc. </li></ul></ul>
  98. 99. Use of Gateways at Present <ul><li>Used in the rare occasion when neither of the internetworking devices could be used for connecting the sub-networks together </li></ul><ul><li>Example </li></ul><ul><ul><li>Connection of a legacy mainframe system to a bus LAN </li></ul></ul>
  99. 100. Rule of Thump <ul><li>Gateways are used for interconnecting vastly differing computing environments together </li></ul>
  100. 101. SNA Gateway SNA Gateway WS WS Mainframe LAN - Ethernet IBM - SNA FEP NIC Card Gateway software Gateway Interface Card
  101. 102. Gateway’s Functional Relationship to the ISO-OSI Model Application Presentation Session Transport Network Data Link Physical Gateway Application Presentation Session Transport Network Data Link Physical
  102. 103. END OF MODULE
  103. 104. END OF MODULE END OF CHAPTER

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