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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>
  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>
  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