Intro to networking

ENG224
INFORMATION TECHNOLOGY – Part II
5. Introduction to Networking
1
Introduction to Network

ENG224
2
What is a Network?
A network consists of 2 or more
entities or objects (computers,
Phones) connected together, and they
can communicate and share
resources (e.g. information)

ENG224
3
Why Networking? / Need
of Networks
• To Share information — i.e. data communication
• Do you prefer these?
• Or this?
To Enhance communication- i.e. Speed and quality

ENG224
4
• Sharing hardware or software
• To Facilitate Centralize administration and support
• e.g. print document
• e.g. Internet-based, so everyone can access the same
administrative or support application from their PCs

ENG224
5
How many kinds of Networks?
•Depending on one’s perspective, we can
classify networks in different ways:
• Based on transmission media: Wired
(UTP, coaxial cables, fiber-optic cables)
and Wireless
• Based on network size: LAN and WAN
(and MAN)
• Based on management method: Peer-to-
peer and Client/Server
• Based on topology (connectivity): Bus,
Star, Ring …

ENG224
6
•Two main categories:
– Guided ― wires, cables
–Unguided ― wireless
transmission, e.g. radio,
microwave, infrared, sound,
sonar.
Based on Transmission
Media

ENG224
7
Based on network size
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 your home

ENG224
8
Local Area Network

ENG224
Metropolitan area network
(MAN)
– A MAN spans the distance of a typical
metropolitan city.
– The cost of installation and operation
is higher.
– MANs use high-speed connections
such as fiber optics to achieve higher
speeds.
Examples: Network of a company in a
town, Cable T.V. Connection etc.
Copyright©,Dec.2013Source:ICTbyProf.SureshKumar
9

ENG224
Metropolitan area network
10

ENG224
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.
• States, countries
• Examples:
• Network of our state
• Internet
WAN
Student
Computer Centre
Your home
USA

ENG224
12
•Example WAN technologies:
•ISDN – Integrated Service Digital
Network
•T-Carriers ― Basically digital
phone lines
•ATM – Asynchronous Transfer
Mode
•SONET – Synchronous Optical
Network

ENG224
• Networks can also be classified
according to the roles that the
networked computers play in the
network’s operation.
• Peer-to-peer
• server-based
• Client-based
Classification by
Component Roles

ENG224
Peer-to-peer:
 In a peer-to-peer network, all computers
are considered equal.
 Each computer controls its own
information and is capable of functioning
as either a client or a server depending
upon the requirement.
 Peer-to-peer networks are inexpensive
and easy to install.
 They are popular as home networks and
for use in small organisations.
Classification by
Component Roles

ENG224
Peer-to-peer (continued):
– Most operating systems come with
built-in peer-to-peer networking
capability.
– The maximum number of peers
that can operate on a peer-to-peer
network is 10.
– Each peer shares resources and
allows others open access to them.
Classification by
Component Roles

ENG224
Peer-to-peer network
Classification by
Component Roles

ENG224
Server-based:
– A server-based network offers
centralized control and is
designed for secure
operations.
– In a server-based network, a
dedicated server controls the
network.
Classification by
Component Roles

ENG224
Server-based (continued):
– A dedicated server is one that services
the network by storing data,
applications, resources, and also
provides access to resources required
by the client.
– These servers can also control the
network’s security from one centralized
location or share it with other specially
configured servers.
Classification by
Component Roles

ENG224
Server-based network
Classification by
Component Roles

ENG224
Client-based:
– Client-based network servers process
requests from clients and return just the
results.
– These networks take advantage of the
powerful processing capabilities of both
the client and the server.
– Application servers and
communications servers are examples
of client-based networks.
Classification by
Component Roles

ENG224
Client-based network
Classification by
Component Roles

ENG224
22
Topology ― 3 basic types
• How so many computers are connected together?
Bus Topology Ring Topology
Star Topology
Hub

ENG224
23
• 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

ENG224
24
How to construct a network
with Bus / Star Topology?
Star Topology
Bus Topology
BNC T-Connector
Coaxial
cable
Network Card

ENG224
25
• 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
T
T
T
dat
a
T
dat
a
T
dat
a
T dat
a
T dat
a
T dat
a
T Ack
T Ack
T Ack
TAck T

ENG224
26
Thank U !

Intro to networking

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Intro to networking

Similar to Intro to networking (20)

More from Suresh Kumar

More from Suresh Kumar (20)

Recently uploaded

Recently uploaded (20)

Intro to networking