introduction to computer networking - behrouz

chapter one of behrouz

1. 1.1
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. Course Instructor – Education
•PhD (Information & Communication) – Chosun University, Korea.
◦Research Interests: ML/AI, Internet of Things, Cybersecurity.
•MS (T&N) – Bahria University, Islamabad.
•Research Interest: Internet of Things
•BS (IT) – University of Peshawar, Peshawar.
•Contact Information:
•Email: [email protected]

3. Course Instructor – Previous
Experience
•Assistant Professor - Namal University, Mianwali
◦Course Taught (Undergrad): Cybersecurity (+Lab), Information Security,
Computer Networks (+Lab).
•Assistant Professor - Chosun University, Korea
◦Course Taught (Graduate): Advanced Network Security, Mobile Computing,
Internet of Things.
•Senior Lab Engineer – Bahria University, Islamabad
◦Labs Taught (Undergrad): Web Engineering
•Lecturer – COMSATS University, Sahiwal.
◦Courses Taught (Undergrad): Programming Fundamentals, OOP, Software
Engineering, Computer Networks.

4. Some Ground Rules
•Use of cell phones
•Discussion with fellows during class
(unless needed for some announced task)
•Early leave (will result in absent)
•Frequent movement In-out during class
•Be interactive, ask questions
•Participate in the lecture
•Relax and learn

5. How to survive this course?
oDo not leave everything until exam night!
oDon't copy the homework! try them by yourself.
oAssignment (avoid plagiarism*) and meet deadlines.
oDeadlines are always FINAL.
oUnannounced quiz! So be prepared.
oMinimum attendance (University policy) is required to sit in
the exam.
•Attendance Policy
•Usually at the start of the class or sometimes randomly
•During the first 10 minutes of the class

6. Grading Policy
•Absolute Grading
Assessment ItemNumber Weight (%)
Assignments 3-4 10
Quizzes 4 10
Midterm 1 25
Project 1 15
Final Exam 1 40

7. Course Information
Course Title: Computer Communication and Networks
Course Code: CEN222
Resources:
Data Communication and Networking, 4th Edition, Behrouz A. Forouzan.
Behrouz A. Forouzan, “TCP/IP Protocol Suite”, McGraw-Hill. (Latest Edition)
A. Leon-Garcia, “Communication Networks”, McGraw-Hill. (Latest Edition)
William Stallings, “Data and Computer Communication”, Prentice Hall. (8th
Edition)
7

8. Objectives
1.To develop an understanding of the concepts related to
Data Communication & Networks
2.To provide detailed insight into the layered structure of OSI
and TCP/IP Models.
3.To apply knowledge of Data Communication & Networks
and layered models in analysis, problem-solving, and
developing small and medium-scale networks.
BY DR. ARSHAD FARHAD 8

9. Course Contents
Network Models: Communication Model, Layered Protocol Architecture, OSI
Reference Model, TCP/IP Architecture.
Physical Layer and Media: Data and Signals, Digital Transmission, Analog
Transmission,
Bandwidth Utilization: Multiplexing, Switching,
Data Link Layer: Error Detection and Correction, Data Link Control, Multiple
Access, Ethernet, LAN and VLAN.
Network Layer: Logical Addressing, Internet Protocol, IP Packet (IPv4),
IP Addressing and Routing: IP Classes and Subnetting, Address Resolution
Protocol (ARP), Reverse Address Resolution Protocol (RARP), Internet Control
Message Protocol (ICMP), Internet Group Management Protocol (IGMP)
BY DR. ARSHAD FARHAD 9

10. Course Contents
Routing Algorithms: Link State Routing, Distance Vector Routing, Address
Mapping, Error Reporting and Multicasting, Delivery, forwarding and routing.
Transport Layer: Process to Process Delivery: UDP, TCP and SCTP, Congestion
Control.
Application Layer: Domain Name System (DNS), Electronic Mail and File
Transfer, WWW, and HTTP.
BY DR. ARSHAD FARHAD 10

11. Lecture Content
 Data communication
 Components of a data communications system
 Data Flow
 Networks
 Network Criteria
 Network Topologies
11

12. 1.12
1-1 DATA COMMUNICATIONS1-1 DATA COMMUNICATIONS
oThe term The term telecommunicationtelecommunication means communication means communication
at a distance. at a distance.
oThe word The word datadata refers to information presented in refers to information presented in
whatever form is agreed upon by the parties creating whatever form is agreed upon by the parties creating
and using the data. and using the data.
oData communicationsData communications are the exchange of data are the exchange of data
between two devices via some form of transmission between two devices via some form of transmission
medium such as a wire cable. medium such as a wire cable.
 Components of a data communications system
 Data Flow
Topics discussed in this section:Topics discussed in this section:

13. 1.13
Figure 1.1 Components of a data communication system

14. 1.14
Figure 1.2 Data flow (simplex, half-duplex, and full-duplex)

15. 1.15
1-2 NETWORKS1-2 NETWORKS
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) )
connected by communication connected by communication linkslinks. A node can be a . A node can be a
computer, printer, or any other device capable of sending computer, printer, or any other device capable of sending
and/or receiving data generated by other nodes on the and/or receiving data generated by other nodes on the
network. A link can be a cable, air, optical fiber, or any network. A link can be a cable, air, optical fiber, or any
medium which can transport a signal carrying medium which can transport a signal carrying
information.information.
 Network Criteria
 Physical Structures
 Categories of Networks
Topics discussed in this section:Topics discussed in this section:

16. 1.16
Network Criteria

Performance

Depends on Network Elements

Measured in terms of Delay and Throughput

Reliability

Failure rate of network components

Measured in terms of availability/robustness

Security

Data protection against corruption/loss of data due to:

Errors

Malicious users

17. 1.17
Physical Structures

Type of Connection

Point to Point - single transmitter and receiver

Multipoint - multiple recipients of single transmission

Physical Topology

Connection of devices

Type of transmission - unicast, mulitcast, broadcast

18. 1.18
Figure 1.3 Types of connections: point-to-point and multipoint

19. 1.19
Type of transmission

Unicast
•Definition: This involves sending data from a single sender to a single receiver.
•Example: Sending an email from your personal account to a specific recipient.

Multicast
•Definition: This involves sending data from a single sender to a group of receivers that have subscribed to the
same multicast group.
•Example: Streaming a live video to a group of viewers interested in the same content.

Broadcast
•Definition: This involves sending data from a single sender to all devices on a network.
•Example: Sending a network-wide announcement or a network discovery request.
Feature Unicast Multicast Broadcast
Sender-Receiver
Relationship One-to-one One-to-many One-to-all
Scope
Limited to specific
recipients Targeted to a group Network-wide
Efficiency
Efficient for targeted
communication
Efficient for group
communication Less efficient for large networks
Addressing
Unique IP address for
each receiver
Multicast group
address
Broadcast address (typically
255.255.255.255)

20. 1.20
Figure 1.4 Categories of topology

21. 1.21
Figure 1.5 A fully connected mesh topology (five devices)

22. 1.22
Figure 1.6 A star topology connecting four stations

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Figure 1.7 A bus topology connecting three stations

24. 1.24
Figure 1.8 A ring topology connecting six stations

25. 1.25
Figure 1.9 A hybrid topology: a star backbone with three bus networks

26. 1.26
Categories of Networks

Local Area Networks (LANs)

Short distances

Designed to provide local interconnectivity

Wide Area Networks (WANs)

Long distances

Provide connectivity over large areas

Metropolitan Area Networks (MANs)

Provide connectivity over areas such as a city, a campus

27. 1.28
Figure 1.11 WANs: a switched WAN and a point-to-point WAN

28. 1.29
Figure 1.12 A heterogeneous network made of four WANs and two LANs

29. 1.32
1-4 PROTOCOLS1-4 PROTOCOLS
A protocol is synonymous with rule. It consists of a set of A protocol is synonymous with rule. It consists of a set of
rules that govern data communications. It determines rules that govern data communications. It determines
what is communicated, how it is communicated and when what is communicated, how it is communicated and when
it is communicated. The key elements of a protocol are it is communicated. The key elements of a protocol are
syntax, semantics and timingsyntax, semantics and timing
 Syntax
 Semantics
 Timing
Topics discussed in this section:Topics discussed in this section:

30. 1.33
Elements of a Protocol

Syntax

Structure or format of the data

Indicates how to read the bits

Semantics

Interprets the meaning of the bits

Knows which fields define what action

Timing

When data should be sent and what

Speed at which data should be sent or speed at which it is
being received.