Week1- basic Introduction to computer networks .pdf

This Slide contains all basic defines and descriptions about computer network and its components

1. Computer Networks
COSC-2104
Course Instructor: Dr. Madiha Amjad
[email protected]

Lecture 1: Introduction
Institute of Information Technology
Khawaja Fareed University of Engineering and
Technology (KFUEIT)

2. Agenda
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Course Details
Data communication and networking
Communication Model
Data Flow
Computer Networks
Topology
Types of networks

3. Course Information
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Instructor: Dr. Madiha Amjad
Ph.D. IT from National University of Sciences and Technology (NUST), Islamabad
MS from University of Engineering and Technology (UET), Lahore
Lecture Timing
Wed 10:55p:m-12:10p:m
Thursday 12:30 p:m-02:00 p:m
Office Hours
Thursday 2:30 a:m-4:00 p:m (Or by appointment)

4. Course Learning Objectives (CLOs)
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Understand the fundamental principles of communication and
networking.
Explain the services and functions provided by each layer in the
internet protocol stack.
Identify various internet working devices and protocols, and their
functions in a network.
Analyze working and performance of key technologies, algorithms and
protocols.

5. Pedagogy
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Lectures
Quiz and assignments
Project/Presentation
Labs

6. Student Evaluation Criteria
Attendance (75 % attendance is mandatory) 5%
Workshop / Assignments/Case study 5%
Surprise Test/Sudden Test, Quizzes 5%
Semester Project/Presentation 10%
Mid Term Paper 25%
Final Term paper 50%
Total 100%

7. Reference Books
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Data communication and networking by Behrouz A. Forouzan, McGraw
-Hill Science, Edition 5 (Course Book)

Computer Networks by Andrew Tanenebaum

Data and computer communication by William Stalling, 9
th Edition
(Course Book)

8. Student Responsibilities

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Students must attend class, 75% attendance is mandatory
Cellular Phones and Beeper must be Turned off
Do not talk to your friends during lecture
Students are also responsible for doing all assigned work on time

9. 1-1 DATA COMMUNICATIONS
The word data refers to information presented in whatever form is
agreed upon by the parties creating and using the data. Data
communications are the exchange of data between two devices via
some form of transmission medium such as a wire cable.
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Characters of Data Communication System
Delivery: - Deliver data to the correct destination
Accuracy :- System must deliver data accurately with out
modification.
Timeliness:- System must deliver data in a timely manner
Jitter:- Variation in packet arrival time.

10. Message:- Information to be communicated.
Sender:- Device that sends data.
Receiver:- Device that receives the message.
Medium:- Physical path by which a message travels
Protocol:- Set of rule governing data communication.

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Figure 1.1 Components of a data communication system

11. Physical Transmission Media
plastic outer
coating
woven or
braided metal
insulating
material
copper wire
twisted-pair cable twisted-pair wire
protective
coating
glass cladding
optical fiber
core

12. Wireless Transmission Media
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Microwaves
Radio waves providing high speed transmission
They are point-to-point (can't be obstructed, require line of sight
communication)
Used for satellite communication
Infrared (IR)
Wireless transmission media that sends signals using infrared light-
waves - Such as?
Mouse, printer, smart phones
Broadcast Radio
Distribute signals through the air over long distance
Typically for stationary locations
Can be short range Bluetooth, Wi-Fi, Wi-max
Cellular Radio
A form of broadcast radio used for mobile
communication
High frequency radio waves to transmit voice or data
Utilizes frequency-reuse

13. PROTOCOLS
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A protocol is synonymous with rule. It consists of a set of rules that
govern data communications. It determines what is communicated,
how it is communicated and when it is communicated. The key
elements of a protocol are syntax, semantics and timing
Syntax
Semantics
Timing

14. Elements of a Protocol
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Syntax
Structure or format of the data
Indicates how to read the bits - field delineation
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.

15. Communication Software (Protocols)
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Examples of applications (Layer 7) take advantage of the transport (Layer 4) services of
TCP and UDP
Hypertext Transfer Protocol (HTTP): A client/server application that uses TCP for transport to
retrieve HTML pages.
Domain Name Service (DNS): A name-to-address translation application that uses both TCP
and UDP transport.
Telnet: A virtual terminal application that uses TCP for transport.
File Transport Protocol (FTP): A file transfer application that uses TCP for transport.
Trivial File Transfer Protocol (TFTP): A file transfer application that uses UDP for transport.
Border Gateway Protocol (BGP): An exterior gateway routing protocol that uses TCP for
transport. BGP is used to exchange routing information for the Internet and is the protocol used
between service providers.

16. 1.16
Figure 1.2 Data flow (simplex, half-duplex, and full-duplex)

17. NETWORKS
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 can be a cable, air, optical fiber, or any
medium which can transport a signal carrying information.
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Network Criteria
Physical Structures
Categories of Networks
Topics discussed in this section:

18. 1.18
Network Criteria
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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

19. 1.19
Physical Structures
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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

20. 1.20
Figure 1.3 Types of connections: point-to-point and multipoint

21. Network Topologies
personal
computer
personal
computer
personal
computer
personal
computer
personal
computer
host
computer
printer
file server
personal computer
personal computer
personal computer
personal computer

22. Network coverage
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Local Area Networks:
Used for small networks (school, home, office)
Examples and configurations:
Wireless LAN or Switched LAN
ATM LAN, Frame Ethernet LAN
Peer-2-PEER: connecting several computers together (<10)
Client/Server: The serves shares its resources between different clients
Metropolitan Area Network
Backbone network connecting all LANs
Can cover a city or the entire country
Wide Area Network
Typically between cities and countries
Technology:
Circuit Switch, Packet Switch, Frame Relay, ATM
Examples:
Internet P2P: Networks with the same network software can be connected together (Napster)

23. Switching

24. Network Examples
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IEEE 802.15.4
Low-rate wireless personal area networks (LR-WPANs)
Bases for e ZigBee, WirelessHART, and MiWi specification
Also used for 6LoWPAN and standard Internet protocols to build a Wireless Embedded Internet (WEI)
Intranets
Used for private networks
May implement a firewall
Hardware and software that restricts access to data and information on a network
Home networks
Ethernet
Phone line
HomeRF (radio frequency- waves)
Intelligent home network
Vehicle-to-Vehicle (car2Car) - http://www.car-to-car.org/
A wireless LAN based communication system to guarantee European-wide inter-vehicle operability

Car2Car Technology: http://www.youtube.com/watch?v=8tFUsN3ZgR4

25. Emerging Technologies
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m-Cash
Pay using your cell phone
Scan-free shopping using Radio frequency identification
VeriChip
Implanted computer chip in the body!
RFID
Wearable computer technology
Implanting a cell phone is in your tooth!
Power over Ethernet (PoE)
Transferring electrical power, along with data, to remote devices over standard category 5 cable
in an Ethernet network
PoE Plus (802.3at) provides more available power
Power over fiber?

26. Emerging Technologies
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Ethernet over powerline
allowing to route data packets through the electrical lines
Up to 200 times faster than DSL (200 Mbps)
Useful when concrete, metal, or other obstructions in the walls and wireless cannot
operate well
Energy-efficient Ethernet
IEEE P802.3az Energy Efficient Ethernet
Task Force
mechanism to reduce power consumption during periods of low link utilization
No frames in transit shall be dropped or corrupted during the transition to and from
the lower level of power consumption
Uses low-power idle proposal for use with 100 Mbit and Gbit connections (causing
possible latency for 10G-bit Ethernet)

27. Summary
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Data communication and networking
Communication
Networks

28. Home Assignment
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Explore applications of Zigbee, Bluetooth, IrDa, RFID
Write two applications along with the frequency range, coverage
range and data rate of each technology mentioned above.
Make a .pdf file of your work
Name file with your registration number for example CS1811109
Assignments must be uploaded on LMS (for this assignment just send it
in email)
Copied material will be marked zero