1. CHAPTER Network Hardware

2. Chapter Objectives Describe the important basic network hardware and the internetworking hardware Discuss the desired characteristics of a server and a workstation Present different switching technologies Examine the routing process with the help of an example

3. Classification of Basic Network Hardware Components Network Interface Cards (NICs) Cables Connectors Servers Workstations

4. Classification of Internetworking Hardware Components Line drivers or repeaters Transceivers Intelligent hubs Bridges Switches Routers Gateways

5. Chapter Modules Network interface cards Network connectors and hubs Server and workstation hardware Repeater Bridge Switch Continued..

6. Continuation of Chapter Modules Switching technology Router Gateway

7. END OF CHAPTER INTRODUCTION

8. MODULE Network Interface Cards (NICs)

9. Network Interface Card Types 10BaseT cards –Physical star networks –10 Mbps speed –Ethernet standard –Twisted pair wiring 10base2 cards –Physical bus networks –10 Mbps speed –Ethernet standard –Thin coaxial wiring

10. Continuation of NIC Types 10Base5 –10 Mbps speed –Ethernet standard –Thick coaxial wiring 100BaseTX –100 Mbps speed –Fast Ethernet standard –Twisted pair Higher quality Category 5 wires are recommended

11. Token Ring Cards Token ring network cards Earlier token ring cards –4 Mbps Newer token ring cards –16 Mbps

12. Bus Types for NICs Card connector types –Newer PCI bus – Older ISA, VESA and EISA bus types ISA bus width –16-bit PCI bus width –Usually 32-bit –Supports 64-bit as well Used in high-powered network servers

13. Cable Connections for NICs BNC barrel connector –Thin coaxial RJ 45 –Twisted pair

14. AUI and Combo Cable Connections for NICs AUI Possibilities –Designed for a thick coaxial cable –Designed for a token ring network –Provided for connecting a transceiver Combo Cards –Consisting of different ports –BNC, RJ-45, AUI

15. Possible Combo Card Connections Thin coaxial cables (BNC) Twisted pair wires (RJ-45) Thick coaxial cables (AUI)

16. Description of an Actual NIC 10BaseT, PCI card –10 = speed in Mbps –Base =Ethernet –T = Twisted pair –32-bit = bus width –PCI = bus technology

17. END OF MODULE

18. MODULE Sample Network Interface Cards

19. Example of a 10Base2 Card BNC Source: Black Box

20. Example of a 10BaseT Card RJ 45 ISA Source: Black Box

21. Example of a Combo Card Combo Source: Black Box RJ 45 BNC

22. END OF MODULE

23. MODULE Network Connectors and Hubs

24. Simple Connectors T connectors –An interface between the NIC and the cables Terminators –Used at both ends of a bus network Terminator T Connector

25. Example of T-Connector and Terminator T Connector Terminator Source: Black Box

26. Connectors : Hubs Types –Active hub –Passive hub Passive hubs –Simply provides the physical and the electrical connection for the network Active hubs –Has built-in intelligence –Some are manageable hubs

27. Connectors : Passive Hub MAU WS Hub Connecting A Token-ring Network WS

28. An Active Hub Backbone Manageable Hub Remote Workstation WS Remote Monitor Active Hub

29. Hub Management Software Sophisticated Monitor the network traffic through each of the ports Becoming popular Standardized protocol for remote management exists –SNMP (Simple Network Management Protocol)

30. Example of a Hub Used in Ring Network Source: Black Box

31. Example of Hubs Used in the Star Network Stackable Hubs Source: Black Box

32. END OF MODULE

33. MODULE Server and Workstation Hardware

34. Module Objectives Give an overview of the different types of the server hardware Discuss the desired characteristics of a server Provide a specification for a workstation

35. Servers Backbone of a network Types –Powerful micros –Servers –Super-servers –Sometimes mini-computers are used as servers In a client-server, the server also acts as an engine of database execution In general, it is used for the sharing of stored data and application

36. Desired Characteristics of Server: Processor and Storage Requirement Powerful processor –Latest Pentium Processor –Multiple processors, if appropriate Large storage space –Several gigabytes at a minimum –Actual requirement will vary LAN size Fast disk access speed –Less than 10 ms

37. Desired Characteristics of a Server: CD-ROM Fast CD-ROM drives CD-ROM towers are often preferred

38. Desired Characteristics of Server: Storage Technology Better hard disk technology –SCSI Fast access Daisy chaining of devices –Latest SCSI technology is required Possible consideration given to fiber- channel in the future

39. Desired Characteristics of Server: Bus and Memory Technologies Better bus technology –PCI Memory –In excess of 128 Mbytes –SDRAM or similar memory technology functioning at 10 nanoseconds or less –The 128-pin SDRAM is also known as the DIMM chips as opposed to the 72-pin SIMM chips

40. Desired Characteristics of Server: Reliability Good back-up facilities –Back-up tape Uniterruptible Power Supply (UPS)

41. Fault Tolerant Feature for Servers RAID storage technology –A system based on multiple disk –Hot-swappable disks Redundant power supply –Hot-swappable power supply

42. Workstation Most applications are executed at the workstation Therefore, it must be powerful in terms of the processor and the memory 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

43. Workstation Processor and Memory Powerful processor –Pentium class processor Adequate memory –32 Mbytes or more –DIMM preferred although fast EDO SIMM may also be used

44. Workstation Storage and Compatibility Sufficient storage –Storage in gigabytes –Important in a client-server environment –Front-end tools are stored on the workstation Speed of storage –Ultra DMA or SCSI preferred –EIDE may also be used Hardware components with appropriate drivers for the client operating system

45. Reliability Power surge protector Uninterruptible Power Supply (UPS), for critical applications

46. END OF MODULE

47. MODULE Repeater

48. An Overview of Repeaters Used for extending the physical span of a network –An example is the extension of the distance between a hub and a node Span is often limited by design considerations 10base5 –The span is limited to 500 meters

49. A Repeater Connection Expanding the Span of the Network Source: Black Box

50. Another Example of Repeater Connection Extending the distance between the backbone and the nodes. Source: Black Box

51. Operations of a Repeater Within the ISO OSI Model Operates at the lower level of the ISO OSI model –Physical layer Medium Physical Layer Repeater Medium Physical Layer

52. Other Devices Used for Extending the Span of a Network Line Drivers Short-Haul Modems

53. END OF MODULE

54. MODULE Bridge

55. An Overview of a Bridge A device used for connecting two LANs operating under the same protocol Currently, the term bridge is loosely being used to describe different interconnecting devices –Used now for connecting LANs operating under different protocols as well

56. Purpose of a Bridge Facilitate the movement of data packet from one network segment to another Not a sophisticated internetworking device Bridge does not perform the routing of information to different segments of a network Connects two network segments and not multiple network segments

57. Bridge Bridge : ISO-OSI Layer of Operation 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. Practical Bridge Implementations Local Bridge Remote Bridge

59. Local and Remote Bridges Local bridge –Connects two different LANs located locally Remote bridge –Connects LAN segments that are geographically apart –An example is a device that provide dial- up access to a LAN

60. A Practical Bridge Example Source: Black Box

61. END OF MODULE

62. MODULE Switch

63. Switch Definition and Purpose A switch is defined as a device that allows a LAN to be segmented –The segments will operate under the same protocol

64. Difference Between a Switch and a Bridge A switch focuses on segmenting a LAN A bridge is concerned with linking two network segments that operate under different protocols

65. Purpose of a Switch Improve the network performance and reliability Better manage the network in general

66. Performance Improvement in Segmented Networks Performance is improved especially in the case of a bus network Multiple bus paths are now available for communication Each segment can engage in simultaneous communication within itself Easier to isolate a problem to a segment –Thus, better manage the entire network

67. Network Reliability When one segment does not function, the other segments can continue to function –Offers better reliability to at least part of the function

68. Switches in Ethernet and Token Ring LANs Switches were originally designed for segmenting Ethernet LANs –Used extensively in configuring large Ethernet bus LANs Physically the network configured would still largely remain based on the star topology Switches are now available for token ring networks as well

69. Use of Switches in Linking LAN Segments Switch Hub WSServerWSServer Segment 1 Segment 2 Crossover Traffic

70. Using A Switch to Link Bus LAN Segments Switch Segment 1Segment 2

71. Use of Switches in Internetworking Because the typical inter-networking connection involves multiple segments, the use of a switch is more common than the use of a bridge

72. WS Use of Switches for Higher Bandwidth 100 MBps Switch WS Each port in theory has a bandwidth of 100 Mbps.

73. END OF MODULE

74. MODULE Switching Technology

75. Module Objectives Explain the basic operation of a switch List the switching technologies and describe their operation –Cut-through and store-and-forward technologies

76. The Basic Operation of Switches A data packet is analyzed Receiver’s addresses is checked If it indicates the receiver to be in the same segment, the packet is dropped If it indicates the receiver to be in a different segment, the packet is forwarded to a different segment Receiver’s Address Sender’s Address Data

77. Switching Technologies There are two major types of switching technologies –Cut-through –Store-and-forward

78. Cut-Through Technology Reads only part of the packet –The addresses header –Packet is forwarded accordingly Bad packets are not filtered

79. Store-and-Forward Technology Entire packet is processed Packets are filtered –Bad packets are filtered

80. Switching Technology Comparison HeaderSender’s AddReceivers AddData Cut-through Store-and-forward

81. Switching Technology Operation at the ISO Layer In each of the two cases of switching technologies no protocol conversion takes place Forwarding and filtering are done at the MAC layer

82. END OF MODULE

83. MODULE Routers

84. The Purpose of a Router Connect LANs operating under different protocols The LANs connected are better known as sub-networks instead of network segments –The term segments is nevertheless used in practice

85. Router Characteristics A router true internetworking device –Connects different sub-networks together Establishes a logical path of communication between the sub- networks Contributes to the modular construction of a network –Network itself is better managed –Network resources are better utilized

86. Internetworking with a Router IEEE 802.3 Sub-network IEEE 802.5 Sub-network PC-NFS Sub-network Router

87. Routers, Switches and Hubs in Perspective Switch Hub SWS Router Hub SWS Hub WSS Hub WS Hub WSS Sub-network 1 Sub-network 2 Backbone

88. Difference Between Routers, Switches and Hubs Hubs –Simply provides the mechanical and electrical connections between the nodes Switches –Examine the data packet for the destination address –Do not alter the data packets Routers –Examine and alter the data packets –Perform protocol conversion

89. Router Requirements Requires more processing power compared to switches and bridges Operations fall within the network layer of the ISO-OSI communication model

90. Router : Network Layer Interface X MEDIUM PHYSICAL LAYER PHYSICAL LAYER DATA LINK LAYER DATA LINK LAYER NETWORK LAYER ROUTER NETWORK LAYER

91. Devices and Layers PHYSICAL LAYER DATA LINK LAYER NETWORK LAYER Switches Routers Repeaters Switches Layer 1 Layer 2 Layer 3

92. A Practical Router Example Router Source: Black Box

93. END OF MODULE

94. MODULE Gateway

96. An Introduction to Gateways Gateways are comprehensive internetworking devices They can be computers themselves

97. Gateways in the Past Very popular They were the only devices that could be used for internetworking Computers of the past were not designed with network connections in mind –Interconnection of different computer systems has to be managed and driven by an advanced device such as a gateway

98. The Present Scenario Computers are now designed with due consideration given to network connections Larger networks could today be configured using internetworking devices –Routers, switches, hubs etc.

99. Use of Gateways at Present Used in the rare occasion when neither of the internetworking devices could be used for connecting the sub-networks together Example –Connection of a legacy mainframe system to a bus LAN

100. Rule of Thump Gateways are used for interconnecting vastly differing computing environments together

101. SNA Gateway SNA Gateway WS Mainframe LAN - Ethernet IBM - SNA FEP NIC Card Gateway software Gateway Interface Card

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

103. END OF MODULE

104. END OF MODULE END OF CHAPTER