MINISTRY OF EDUCATION
DIPLOMA IN
INFORMATION COMMUNICATION
TECHNOLOGY
KENYA INSTITUTE OF CURRICULUM DEVELOPMENT
STUDY NOTES
Data Communication & Networking
MODULE III: SUBJECT NO 3
Page 1 of 109
,Contents
TOPIC 1: DATA COMMUNICATION AND NETWORKING ........................................................... 5
T1.1) Meaning of computer network........................................................................................................ 5
T1.2) Components of computer network ................................................................................................. 5
T1. 3) Types of computer networks .......................................................................................................... 7
T1.4) Role of computer networks ............................................................................................................. 9
T1.5) Network topologies ....................................................................................................................... 10
What is a Topology? ............................................................................................................................ 10
Main Types of Physical Topologies ..................................................................................................... 10
Considerations When Choosing a Topology ....................................................................................... 14
T1.6) Categories of computer networks ................................................................................................. 14
Peer-to-peer network(p2p)................................................................................................................. 15
Server-based network ......................................................................................................................... 16
TOPIC 2: NETWORK MEDIA............................................................................................................... 17
T2.1) Electrical properties of matter....................................................................................................... 17
State of State? ..................................................................................................................................... 17
Properties of Solids ............................................................................................................................. 17
Band theory ...................................................................................................................................... 18
Effect of temperature on conductivity ............................................................................................... 19
T2.2, T2.3,T2. 4) Types of transmission media, Importance and benefits and limitations ..................... 19
Transmission medium ......................................................................................................................... 19
Telecommunications ........................................................................................................................... 20
Bounded/Guided Transmission Media ............................................................................................... 20
UnBounded/UnGuided Transmission Media ...................................................................................... 25
TOPIC 3: DATA COMMUNICATION ................................................................................................. 29
T3.1) Meaning of data communication .................................................................................................. 29
T3.2) Principles of data communication ................................................................................................. 29
T3.3) Techniques in data communication............................................................................................... 34
T3.4) Networking models and their importance .................................................................................... 34
T3.5) OSI model and different layers ...................................................................................................... 35
T3.6) T7.2) Standards for Ethernet ......................................................................................................... 40
T3.7) Networking components as they map to OSI models ................................................................... 45
Page 2 of 109
, T3.8) TCP models and functions of different layers................................................................................ 48
T3.9) Comparison between OSI model and TCP model .......................................................................... 48
TOPIC 4: NETWORK CONNECTIONS AND PROTOCOLS ........................................................... 50
T4.1) Transport protocols ....................................................................................................................... 50
T4.2) Other protocols .............................................................................................................................. 50
T4.3) Network connectivity ..................................................................................................................... 52
TOPIC 5: LOCAL AREA NETWORK .................................................................................................. 56
T5.1) Meaning of local area network ...................................................................................................... 56
T5.2,T5.3) LAN protocols and LAN transmission methods and Access methods ................................... 56
LAN Protocols ...................................................................................................................................... 56
Network Protocol & Types .................................................................................................................. 56
Media-Access Methods ....................................................................................................................... 59
LAN Transmission Methods ................................................................................................................ 59
LAN Topologies ................................................................................................................................... 59
LAN Devices......................................................................................................................................... 60
TOPIC 6: WIDE AREA NETWORK ..................................................................................................... 61
T6.1) Meaning & Types of WAN.............................................................................................................. 61
T6.2) WAN protocols ............................................................................................................................... 61
TOPIC 7: ETHERNET TECHNOLOGY .............................................................................................. 65
T7.1) Ethernet technology ...................................................................................................................... 65
T7.2) Ethernet standards ........................................................................................................................ 65
TOPIC 8: NETWORK TROUBLE SHOOTING .................................................................................. 67
T8.1) Meaning and importance of network trouble shooting ................................................................ 67
T8.2) Methods of network trouble shooting .......................................................................................... 68
TOPIC 9: NET WORK SECURITY ....................................................................................................... 73
T9.1) Network security............................................................................................................................ 73
Importance Of Network Security For Business Organization: ............................................................ 73
Data, Vulnerabilities, and Countermeasures ....................................................................................... 73
T9.2) Security techniques........................................................................................................................ 74
T9.3) Security threats and other network vulnerabilities ....................................................................... 76
Common Network Security Threats .................................................................................................... 76
Types of Network Attacks ................................................................................................................... 77
Page 3 of 109
, TOPIC 10: NETWORK DESIGN ........................................................................................................... 86
T10.1) Meaning of network design ......................................................................................................... 86
T10.2) Computer development life cycle ................................................................................................ 86
T10.3) Hardware and Software selection criteria ................................................................................... 88
TOPIC 11: TCP/IP PROTOCALS .......................................................................................................... 91
T11.1) Meaning of TCP/IP concepts ........................................................................................................ 91
T11.2) Types of data flow........................................................................................................................ 92
TOPIC 12: COMMUNICATION SOFTWARE .................................................................................... 94
T12.1) Meaning of terms (computer software and network software) ................................................. 94
T12.2) Different types of communication software ............................................................................... 94
T12.3) Types of network software .......................................................................................................... 95
TOPIC 13: INTERNET ............................................................................................................................ 96
T13.1) Meaning and importance of internet .......................................................................................... 96
Definition of Terms ............................................................................................................................. 96
Importance of the internet to your organisation ............................................................................... 96
TOPIC 14: EMERGING TRENDS ......................................................................................................... 99
T14.1) Emerging trends in networking ................................................................................................... 99
T14.2) Challenges of emerging trends in networking ........................................................................... 102
T14.3) Coping with challenges of emerging trends in networking ....................................................... 104
Page 4 of 109
DIPLOMA IN
INFORMATION COMMUNICATION
TECHNOLOGY
KENYA INSTITUTE OF CURRICULUM DEVELOPMENT
STUDY NOTES
Data Communication & Networking
MODULE III: SUBJECT NO 3
Page 1 of 109
,Contents
TOPIC 1: DATA COMMUNICATION AND NETWORKING ........................................................... 5
T1.1) Meaning of computer network........................................................................................................ 5
T1.2) Components of computer network ................................................................................................. 5
T1. 3) Types of computer networks .......................................................................................................... 7
T1.4) Role of computer networks ............................................................................................................. 9
T1.5) Network topologies ....................................................................................................................... 10
What is a Topology? ............................................................................................................................ 10
Main Types of Physical Topologies ..................................................................................................... 10
Considerations When Choosing a Topology ....................................................................................... 14
T1.6) Categories of computer networks ................................................................................................. 14
Peer-to-peer network(p2p)................................................................................................................. 15
Server-based network ......................................................................................................................... 16
TOPIC 2: NETWORK MEDIA............................................................................................................... 17
T2.1) Electrical properties of matter....................................................................................................... 17
State of State? ..................................................................................................................................... 17
Properties of Solids ............................................................................................................................. 17
Band theory ...................................................................................................................................... 18
Effect of temperature on conductivity ............................................................................................... 19
T2.2, T2.3,T2. 4) Types of transmission media, Importance and benefits and limitations ..................... 19
Transmission medium ......................................................................................................................... 19
Telecommunications ........................................................................................................................... 20
Bounded/Guided Transmission Media ............................................................................................... 20
UnBounded/UnGuided Transmission Media ...................................................................................... 25
TOPIC 3: DATA COMMUNICATION ................................................................................................. 29
T3.1) Meaning of data communication .................................................................................................. 29
T3.2) Principles of data communication ................................................................................................. 29
T3.3) Techniques in data communication............................................................................................... 34
T3.4) Networking models and their importance .................................................................................... 34
T3.5) OSI model and different layers ...................................................................................................... 35
T3.6) T7.2) Standards for Ethernet ......................................................................................................... 40
T3.7) Networking components as they map to OSI models ................................................................... 45
Page 2 of 109
, T3.8) TCP models and functions of different layers................................................................................ 48
T3.9) Comparison between OSI model and TCP model .......................................................................... 48
TOPIC 4: NETWORK CONNECTIONS AND PROTOCOLS ........................................................... 50
T4.1) Transport protocols ....................................................................................................................... 50
T4.2) Other protocols .............................................................................................................................. 50
T4.3) Network connectivity ..................................................................................................................... 52
TOPIC 5: LOCAL AREA NETWORK .................................................................................................. 56
T5.1) Meaning of local area network ...................................................................................................... 56
T5.2,T5.3) LAN protocols and LAN transmission methods and Access methods ................................... 56
LAN Protocols ...................................................................................................................................... 56
Network Protocol & Types .................................................................................................................. 56
Media-Access Methods ....................................................................................................................... 59
LAN Transmission Methods ................................................................................................................ 59
LAN Topologies ................................................................................................................................... 59
LAN Devices......................................................................................................................................... 60
TOPIC 6: WIDE AREA NETWORK ..................................................................................................... 61
T6.1) Meaning & Types of WAN.............................................................................................................. 61
T6.2) WAN protocols ............................................................................................................................... 61
TOPIC 7: ETHERNET TECHNOLOGY .............................................................................................. 65
T7.1) Ethernet technology ...................................................................................................................... 65
T7.2) Ethernet standards ........................................................................................................................ 65
TOPIC 8: NETWORK TROUBLE SHOOTING .................................................................................. 67
T8.1) Meaning and importance of network trouble shooting ................................................................ 67
T8.2) Methods of network trouble shooting .......................................................................................... 68
TOPIC 9: NET WORK SECURITY ....................................................................................................... 73
T9.1) Network security............................................................................................................................ 73
Importance Of Network Security For Business Organization: ............................................................ 73
Data, Vulnerabilities, and Countermeasures ....................................................................................... 73
T9.2) Security techniques........................................................................................................................ 74
T9.3) Security threats and other network vulnerabilities ....................................................................... 76
Common Network Security Threats .................................................................................................... 76
Types of Network Attacks ................................................................................................................... 77
Page 3 of 109
, TOPIC 10: NETWORK DESIGN ........................................................................................................... 86
T10.1) Meaning of network design ......................................................................................................... 86
T10.2) Computer development life cycle ................................................................................................ 86
T10.3) Hardware and Software selection criteria ................................................................................... 88
TOPIC 11: TCP/IP PROTOCALS .......................................................................................................... 91
T11.1) Meaning of TCP/IP concepts ........................................................................................................ 91
T11.2) Types of data flow........................................................................................................................ 92
TOPIC 12: COMMUNICATION SOFTWARE .................................................................................... 94
T12.1) Meaning of terms (computer software and network software) ................................................. 94
T12.2) Different types of communication software ............................................................................... 94
T12.3) Types of network software .......................................................................................................... 95
TOPIC 13: INTERNET ............................................................................................................................ 96
T13.1) Meaning and importance of internet .......................................................................................... 96
Definition of Terms ............................................................................................................................. 96
Importance of the internet to your organisation ............................................................................... 96
TOPIC 14: EMERGING TRENDS ......................................................................................................... 99
T14.1) Emerging trends in networking ................................................................................................... 99
T14.2) Challenges of emerging trends in networking ........................................................................... 102
T14.3) Coping with challenges of emerging trends in networking ....................................................... 104
Page 4 of 109
