Contents
About the Tutorial ..................................................................................................................................... i
Audience .................................................................................................................................................... i
Prerequisites .............................................................................................................................................. i
Disclaimer & Copyright .............................................................................................................................. i
Contents ................................................................................................................................................... ii
1. OVERVIEW ............................................................................................................................ 1
Classification of Computer Networks ........................................................................................................ 1
Geographical Span .................................................................................................................................... 1
Inter-Connectivity ..................................................................................................................................... 1
Administration .......................................................................................................................................... 2
Network Architecture ............................................................................................................................... 2
Network Applications ............................................................................................................................... 2
2. TYPES OF COMPUTER NETWORKS ........................................................................................ 3
Personal Area Network ............................................................................................................................. 3
Local Area Network................................................................................................................................... 3
Metropolitan Area Network ..................................................................................................................... 4
Wide Area Network .................................................................................................................................. 5
Internetwork............................................................................................................................................. 6
3. NETWORK LAN TECHNOLOGIES ............................................................................................ 8
Ethernet .................................................................................................................................................... 8
Fast-Ethernet ............................................................................................................................................ 8
Giga-Ethernet ............................................................................................................................................ 8
Virtual LAN................................................................................................................................................ 9
4. COMPUTER NETWORK TOPOLOGIES ................................................................................... 10
Point-to-Point ......................................................................................................................................... 10
Bus Topology .......................................................................................................................................... 10
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Star Topology .......................................................................................................................................... 11
Ring Topology ......................................................................................................................................... 12
Mesh Topology ....................................................................................................................................... 13
Tree Topology ......................................................................................................................................... 14
Daisy Chain ............................................................................................................................................. 15
Hybrid Topology...................................................................................................................................... 15
5. COMPUTER NETWORK MODEL ........................................................................................... 17
Layered Tasks.......................................................................................................................................... 17
OSI Model ............................................................................................................................................... 18
Internet Model ....................................................................................................................................... 19
6. COMPUTER NETWORK SECURITY ........................................................................................ 20
Secret Key Encryption ............................................................................................................................. 21
Public Key Encryption ............................................................................................................................. 21
Message Digest ....................................................................................................................................... 21
7. PHYSICAL LAYER INTRODUCTION ........................................................................................ 22
Signals ..................................................................................................................................................... 22
Transmission Impairment ....................................................................................................................... 22
Transmission Media ................................................................................................................................ 23
Channel Capacity .................................................................................................................................... 23
Multiplexing............................................................................................................................................ 24
Switching ................................................................................................................................................ 24
8. DIGITAL TRANSMISSION ...................................................................................................... 25
Digital-to-Digital Conversion ................................................................................................................... 25
Line Coding ............................................................................................................................................. 25
Unipolar Encoding ................................................................................................................................... 26
Polar Encoding ........................................................................................................................................ 26
Bipolar Encoding ..................................................................................................................................... 28
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Block Coding ........................................................................................................................................... 28
Analog-to-Digital Conversion .................................................................................................................. 29
Sampling ................................................................................................................................................. 29
Quantization ........................................................................................................................................... 29
Encoding ................................................................................................................................................. 30
Transmission Modes ............................................................................................................................... 30
9. ANALOG TRANSMISSION ..................................................................................................... 32
Digital-to-Analog Conversion .................................................................................................................. 32
Analog-to-Analog Conversion ................................................................................................................. 34
10. TRANSMISSION MEDIA........................................................................................................ 38
Magnetic Media ...................................................................................................................................... 38
Twisted Pair Cable .................................................................................................................................. 38
Coaxial Cable .......................................................................................................................................... 39
Power Lines ............................................................................................................................................ 40
Fiber Optics ............................................................................................................................................. 40
11. WIRELESS TRANSMISSION ................................................................................................... 42
Radio Transmission ................................................................................................................................. 42
Microwave Transmission ........................................................................................................................ 43
Infrared Transmission ............................................................................................................................. 44
Light Transmission .................................................................................................................................. 44
12. MULTIPLEXING .................................................................................................................... 46
Frequency Division Multiplexing ............................................................................................................. 46
Time Division Multiplexing ..................................................................................................................... 46
Wavelength Division Multiplexing .......................................................................................................... 47
Code Division Multiplexing ..................................................................................................................... 48
13. SWITCHING ......................................................................................................................... 49
Circuit Switching ..................................................................................................................................... 49
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Message Switching.................................................................................................................................. 50
Packet Switching ..................................................................................................................................... 51
14. DATA LINK LAYER INTRODUCTION ...................................................................................... 53
Functionality of Data-link Layer .............................................................................................................. 53
15. ERROR DETECTION AND CORRECTION ................................................................................ 55
Types of Errors ........................................................................................................................................ 55
Error Detection ....................................................................................................................................... 56
Error Correction ...................................................................................................................................... 57
16. DATA LINK CONTROL AND PROTOCOLS .............................................................................. 59
Flow Control ........................................................................................................................................... 59
Error Control ........................................................................................................................................... 60
17. NETWORK LAYER INTRODUCTION ....................................................................................... 64
Layer-3 Functionalities ............................................................................................................................ 64
Network Layer Features .......................................................................................................................... 64
18. NETWORK ADDRESSING ...................................................................................................... 65
19. NETWORK ROUTING ........................................................................................................... 67
Unicast routing ....................................................................................................................................... 67
Broadcast routing ................................................................................................................................... 68
Multicast Routing.................................................................................................................................... 69
Anycast Routing ...................................................................................................................................... 69
Unicast Routing Protocols ....................................................................................................................... 70
Multicast Routing Protocols .................................................................................................................... 70
Routing Algorithms ................................................................................................................................. 71
20. INTERNETWORKING ............................................................................................................ 72
Tunneling ................................................................................................................................................ 72
Packet Fragmentation ............................................................................................................................. 73
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21. NETWORK LAYER PROTOCOLS ............................................................................................ 75
Address Resolution Protocol (ARP) ......................................................................................................... 75
Internet Control Message Protocol (ICMP) .............................................................................................. 76
Internet Protocol Version 4 (IPv4) ........................................................................................................... 76
Internet Protocol Version 6 (IPv6) ........................................................................................................... 77
22. TRANSPORT LAYER INTRODUCTION .................................................................................... 78
Functions ................................................................................................................................................ 78
End-to-End Communication .................................................................................................................... 78
23. TRANSMISSION CONTROL PROTOCOL ................................................................................. 80
Features .................................................................................................................................................. 80
Header .................................................................................................................................................... 80
Addressing .............................................................................................................................................. 82
Connection Management........................................................................................................................ 82
Bandwidth Management ........................................................................................................................ 83
Error Control and Flow Control ............................................................................................................... 84
Multiplexing............................................................................................................................................ 84
Congestion Control ................................................................................................................................. 84
Timer Management ................................................................................................................................ 85
Crash Recovery ....................................................................................................................................... 85
24. USER DATAGRAM PROTOCOL ............................................................................................. 87
Requirement of UDP ............................................................................................................................... 87
Features .................................................................................................................................................. 87
UDP Header ............................................................................................................................................ 87
UDP application ...................................................................................................................................... 88
25. APPLICATION LAYER INTRODUCTION .................................................................................. 89
26. CLIENT-SERVER MODEL ....................................................................................................... 91
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Communication ...................................................................................................................................... 92
27. APPLICATION PROTOCOLS .................................................................................................. 94
Domain Name System ............................................................................................................................. 94
Simple Mail Transfer Protocol ................................................................................................................. 94
File Transfer Protocol .............................................................................................................................. 94
Post Office Protocol (POP) ...................................................................................................................... 95
Hyper Text Transfer Protocol (HTTP) ....................................................................................................... 95
28. NETWORK SERVICES ........................................................................................................... 96
Directory Services ................................................................................................................................... 96
File Services ............................................................................................................................................ 96
Communication Services ......................................................................................................................... 97
Application Services ................................................................................................................................ 97
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