DATA COMMUNICATION AND NETWORKS

Transcription

1 DATA COMMUNICATION AND NETWORKS Lecture: 1 Instructor Mazhar Hussain 1

2 DATA COMMUNICATION AND NETWORKS Blog 2

3 COURSE OUTLINE The course will consist of : 16 lectures 2 assignments 2exams (1 midterm and 1 final) Grading Criteria: One Midterm: 25 % Final Exam: 50% Assignments /Quizz/Presentation: 15% Attendance : 10% 3

4 TEXT BOOKS Data Communications and Networking 4 th Edition by Behrouz A. Forouzan Data and Computer Communication 6 th Edition by William Stallings Computer Networks (5th Edition) by Andrew S. Tanenbaum 4

5 TODAY AGENDA Data Communication Brief History of Communication Data Communication System Key Data Communication Terminology Effectiveness of Data Communication System Components of Data Communication System Key Data Communication Terminologies Why Networks? And types of Networks Network Criteria and Applications Protocols, Elements and Applications of Protocols 5

6 DATA COMMUNICATION DEFINITION Data Communication is the exchange of Information from one entity to the other using a Transmission Medium 6

7 DATA COMMUNICATION Data Communication is the exchange of data (in the form of 0 s and 1 s) between two devices (computers) via some form of the transmission medium. 7

8 LOCAL AND REMOTE COMMUNICATION LOCAL Communicating devices are present in the same building or a similarly restricted geographical area REMOTE Communicating devices are present farther apart 8

9 DATA COMMUNICATION SYSTEM For Data Communication to occur, communicating devices must be a part of a system made up of some specific kind of hardware and software. This system is known as DATA COMMUNICATION SYSTEM 9

10 EFFECTIVENESS OF DATA COMM. SYSTEM Effectiveness depends uponthree fundamental characteristics: Delivery Accuracy Timeliness 10

11 DATA COMMUNICATION SYSTEM 11

12 DATA COMMUNICATION SYSTEM A Data communication system is made up of 5 components: Message Sender Receiver Medium Protocol 12

13 MESSAGE TYPES 13

14 A Complex Data Comm. System 14

15 KEY DATA COMMUNICATION TERMINOLOGY Session: communication dialog between network users or applications Network: interconnected group of computers and communication devices Node: a network-attached device 15

16 KEY DATA COMMUNICATION TERMINOLOGY Link: connects adjacent nodes Path: end-to-end route within a network 16

17 KEY DATA COMMUNICATION TERMINOLOGY Packetizing: dividing messages into fixed-length packets prior to transmission over a network s communication media Routing: determining a message s path from sending to receiving nodes 17

18 A Network is a set of devices (Nodes) connected by Communication Links 18 NETWORK

19 WHY NETWORKS? Point to point communication not usually practical Devices are too far apart Large set of devices would need impractical number of connections 19

20 WHY NETWORKS? Solution is to connect all devicesto a central system known as a NETWORK Two Main Classes ofnetworks Local Area Networks (LANs) Wide Area Network (WANs) 20

21 NETWORK CRITERIA Data Communication Network Criteria Performance Reliability Security 21

22 NETWORK CRITERIA Performance Number of Users Type of Transmission Medium Hardware Software 22

23 Reliability NETWORK CRITERIA Frequency of failure Recovery Time after Failure 23

24 NETWORK CRITERIA Security Unauthorized Access Viruses 24

25 NETWORK APPLICATIONS Marketing andsales FinancialServices Manufacturing ElectronicMessaging Teleconferencing CableTelevision 25

26 PROTOCOLS Set of Rules Governing Communication 26

27 PROTOCOLS Protocols defines: What is Communicated? How, it is Communicated? When, it is Communicated? 27

28 PROTOCOLS Elements of a Protocol: Syntax Semantics Timing 28

29 PROTOCOL ARCHITECTURE Instead of having a single Module for performing communication, there is a structured set of modules that implement communications function 29

30 Simplified File Transfer Architecture 30

31 SUGGESTED READING Section 1.2, Data Communications and Networking 4 th Edition by Behrouz A. Forouzan Sections 1.1, 1.2, Data and Computer Communication 6 th Edition by William Stallings 31

32 SUGGESTED READING Section 1.3, Data Communications and Networking 4 th Edition by Behrouz A. Forouzan Sections 1.3, Data and Computer Communication 6 th Edition by William Stallings 32

33 SUGGESTED READING Section 1.4 Data Communications and Networking 4 th Edition by Behrouz A. Forouzan Sections 1.1,2.1 Data and Computer Communication 6 th Edition by William Stallings 33

34 QUESTIONS/COMMENTS? 34