unit 0 introduction
DESCRIPTION
Unit 0 introductionTRANSCRIPT
![Page 1: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/1.jpg)
Unit 0
Introduction to
Computer Communication Networks
[ Prerequisite ]
![Page 2: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/2.jpg)
Motivation to learn this Subject . . . . . . . . . .
Business
Science
Education
Industry
![Page 3: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/3.jpg)
Topics to be covered in this Introductory Chapter
Data Communications
Networks
Internet
Protocols & Standards
![Page 4: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/4.jpg)
1-1 DATA COMMUNICATIONS
Data communications collectively refers to the exchange of data between two devices via some form of transmission medium ( such as a wire cable ).
Data facts and statistics collected together for reference or analysis.
Communication the imparting or exchanging of information by speaking, writing, or
using some other medium.
a) Effectiveness of a Data Communication Systemb) Componentsc) Data Representation d) Data Flow
Topics discussed in this section:
![Page 5: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/5.jpg)
The effectiveness of a data communication system depends on the following four fundamental characteristics :
~ Delivery [ Destination reached should be correct ]
~ Accuracy [ The data should be 100 % same, as it was, when transmitted ]
~ Timeliness [ The delay should be insignificant ]
~ Jitter [ The speed should be uniform for all data packets ]
a) Effectiveness of a Data Communication System
![Page 6: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/6.jpg)
b) Components of Data Communication System
The five important components of Data Communications are :
~ Message [ Message is the information to be communicated ]
~ Sender [ The sender is the device that sends the message ]
~ Receiver [ The receiver is the device that receives the message ]
~ Transmission Medium [ It is the physical path through which a message travels from sender to receiver
]
~ Protocol [ It is a set of rules that govern data communications ]
![Page 7: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/7.jpg)
c) Data Representation
The data can come in different forms such as :
~ Text [ e.g. a, b, c, X, Y , Z . ]
~ Numbers [ e.g. 0,1,2 , . . . . . . . 9 ]
~ Images [ e.g. *.jpeg , *.png files ]
~ Audio [ e.g. *.mp3 files ]
~ Video [ e.g. *.mp4 , *.avi files etc.]
Data Form
Text
Numbers
Images
Audio
Video
![Page 8: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/8.jpg)
d ) Data Flow
![Page 9: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/9.jpg)
1-2 NETWORKS
What do you mean by network ? A network is a set of devices (often referred to as nodes) connected by communication links.
* A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
* A link is communication pathway that transfers data from one device to another.
a) Distributed Processingb) Network Criteriac) Physical Structuresd) Network Modelse) Categories of Networksf) Interconnection of Networks: Internetwork
Topics discussed in this section:
![Page 10: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/10.jpg)
a) Distributed Processing
Modern day networks use distributed processing, in which a task is divided among multiple computers.
Note : Contrast this with Centralized Processing
![Page 11: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/11.jpg)
b) Network Criteria
~ Performance [ maximum throughput and minimum delay ]
~ Reliability [ the work should continue in spite of any catastrophe ]
~ Security [ Protecting data from manipulation or damage ]
![Page 12: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/12.jpg)
c) Physical Structures
~ Type of Connection [based on type of link]
~ Physical Topology [based on network’s physical
layout ]
![Page 13: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/13.jpg)
Type of Connection
![Page 14: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/14.jpg)
Physical Topology
![Page 15: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/15.jpg)
i) Mesh Topology
![Page 16: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/16.jpg)
ii) Star Topology
![Page 17: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/17.jpg)
iii) Bus Topology
![Page 18: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/18.jpg)
iv) Ring Topology
![Page 19: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/19.jpg)
Hybrid Topology
![Page 20: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/20.jpg)
d) Network Models
~ OSI Model ( 7 - layer model )
~ Internet Model ( 4 - layer model )
![Page 21: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/21.jpg)
e) Categories of Networks
~ Local Area Network ( LAN )
~ Metropolitan Area Network ( MAN )
~ Wide Area Network ( WAN )
![Page 22: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/22.jpg)
i) LAN ( Local Area Network )
![Page 23: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/23.jpg)
ii) MAN ( Metropolitan Area Network )
Typical Cable TV Network[ An example of MAN ]
![Page 24: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/24.jpg)
iii) WAN ( Wide Area Network )
![Page 25: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/25.jpg)
f ) Interconnection of Networks : Internetwork
![Page 26: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/26.jpg)
1-3 THE INTERNET
The Internet is a communication system that has brought a wealth of information to our fingertips and organized it for our use.
The Internet has revolutionized many aspects of our daily lives. It has affected the way we do business as well as the way we spend our leisure time.
![Page 27: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/27.jpg)
Brief History of Internet~ In mid-1960s’, mainframe computers in research organization were stand-alone devices.
~ In 1967, ARPA ( Advanced Research Projects Agency ) presented the idea for ARPANET.
~ By 1969, ARPANET was a reality. [ Four Universities in USA were interconnected ]
~ In 1973, Vint Cerf and Bob Kahn present the landmark paper outlining the foundations for TCP/IP.
Internet Today~ The Internet has come a long way since the 1960s’. It complexity has grown enormously.
~ It is difficult to give an accurate representation of the Internet because it is continually changing.
~ Hierarchy in Internet Usage : IISPs’ ⇋ NISPs’ ⇋ RISPs’ ⇋ LISPs’ ⇋ Users’. Note : ISP stands for Internet Service Provider
![Page 28: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/28.jpg)
Hierarchical organization of the Internet
* ISP stands for Internet Service Provider * NAP stands for Network Access Point
![Page 29: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/29.jpg)
1-4 PROTOCOLS AND STANDARDS
Protocol A protocol is a set of rules that govern data communications
Standards ~ something that is used or accepted as normal or average. ~ something that is used as a measure, norm, or model in
comparative evaluations.
![Page 30: Unit 0 introduction](https://reader033.vdocuments.mx/reader033/viewer/2022061223/54c27ebb4a795974748b471a/html5/thumbnails/30.jpg)
Standards Organization
An Internet Standard is a thoroughly tested specification that is useful to and adhered to by those who work with the Internet. It is a formalized regulation that must be followed.
Internet Standards
Standards are developed through the cooperation of standards creation committees, forums, and government regulatory agencies. A standards organization is one among these. ( e.g. : ISO / ITU-T / ANSI / IEEE / EIA )