Presentation On Computer Network

2. Introduction to Networking

3. A network consists of 2 or more computers
connected together, and they can communicate
and share resources (e.g. information)

4. 4
Why Networking?
• Sharing information — i.e. data communication
• Do you prefer these?
• Or this?

5. Creating Computer
Network

6. Network Benefits
1.Ease Of Access
2.Work From Home
3.Share Resources
4.Share Information
5.Increase Productivity
6.Share Programs
7.Administration
8.Security

7. Transmission Media
Two main categories:
Guided ― wires, cables
Unguided ― wireless transmission, e.g.
radio, microwave, infrared, sound,
sonar
Twisted-Pair cables:
Unshielded Twisted-Pair (UTP)
cables
Shielded Twisted-Pair (STP) cables
Coaxial cables
Fiber-optic cables

8. Types Of Networks
Two types of networks are LAN and WAN:
#. LAN (Local Area Network) – A group of devices
sharing resources in a single area such as a room or a
building.
#. MAN (Metropolitan Area Network) – Collection
of local area network sharing information in
geographical area such as a city or town.
#. WAN (Wide Area Network) – Two or more LANs
communicating, often across large distances. The
most famous WAN is the Internet.

9. • Local Area Network (LAN)
• Small network, short distance
• A room, a floor, a building
• Limited by no. of computers and distance covered
• Usually one kind of technology throughout the
LAN
• Serve a department within an organization
• Examples:
• Network inside the Student Computer Room
• Network inside CF502
• Network inside your home

10. • Metropolitan Area Network (MAN)
• It is a collection of local area network.
• Geographical Area :- City, Town
Example
• Branches of local bank of city

11. 11
• Wide Area Network (WAN)
• A network that uses long-range
telecommunication links to connect 2 or more
LANs/computers housed in different places far
apart.
• Towns, states, countries
• Examples:
• Network of our Campus
• Internet
WAN
Student Computer
Centre
Your home
USA

12. 12
Topology ― 3 basic types
• How so many computers are connected together?
Bus Topology Ring Topology
Star Topology
Hub

13. • Bus Topology
• Simple and low-cost
• A single cable called a trunk (backbone, segment)
•Only one computer can send messages at a time
• Passive topology - computer only listen for, not
regenerate data
• Star Topology
• Each computer has a cable connected to a single point
• More cabling, hence higher cost
• All signals transmission through the hub; if down,
entire network down
• Depending on the intelligence of hub, two or more
computers may send message at the same time

14. 14
How to construct a network with Bus / Star
Topology?
Star Topology
Bus Topology
BNC T-Connector

15. • Ring Topology
• Every computer serves as
a repeater to boost signals
• Typical way to send data:
•Token passing
• only the computer who
gets the token can send
data
• Disadvantages
•Difficult to add computers
• More expensive
• If one computer fails, whole network fails

16. Network Protocol – Specifications that define the network data
communication procedures to follow when sending and receiving
data.
1. TCP/IP (Transport Control Protocol / Internet Protocol) –
the most common network protocol used by most companies
and home users as a standard protocol. Used to access the
Internet.
2. IPX/SPX (Internetwork Packet Exchange/Sequenced
Packet Exchange) – original protocol used for connecting to
Novell networks. Now TCP/IP is the standard protocol used.
3. NetBEUI (NetBIOS Enhanced User Interface) – is a non-routable
protocol used in simple networks; commonly found
on peer-to-peer networks.
4. HTTP (Hypertext transfer protocol) – It is a set of rules for
transferring files (text, graphic images, sound, video, and
other multimedia files) on the World Wide Web.

17. The
End