OSI reference model in Network

warmersafternoonΔίκτυα και Επικοινωνίες

23 Οκτ 2013 (πριν από 5 χρόνια και 18 μέρες)

189 εμφανίσεις

Computer Networks

Sanjeewa

HMC

B.Sc
(
Hons
(
Ruh
))

Reading MIT(Col)

sanjihmc@yahoo.com

Objectives


Brief introduction to computer networks &
understanding sub netting to utilize ip
address block in efficient manner.

Out lines


What is a computer network?


Components of a network.


Advantages of a computer network.


IP Sub netting


IP address


Subnet mask


Purposes of sub netting


Example for sub netting


References






What is a computer network?


A

computer

network

is

a

set

of

interconnected

network

devices

that

allows

them

to

share

data,

information,

software,

hardware

devices

and

processing

power
.

Components of a network


Server


to provide services


Ex: file servers, web servers, data base
servers


Client
-

to get services from those servers.


Ex: web client


Protocols
-

A protocol is an agreement (rules)
between the communicating parties on how
communication is proceed.


Ex: TCP/IP suite


Transmission media


to transfer data between
two network devices.

Transmission Media


Guided Media


Unguided Media


Guided media


Physically connect two devices using
wired connection.


Ex:


Twisted Pair (UTP,STP)


Coaxial cable


Optical fiber

Unguided Media


Physically not connected using wired
connection. use wireless technology to
communicate with each other.


Ex:


wi
-
fi


Infra red

Advantages of computer netwoks


Provides a way to share data, programs,
computing power and information.


Online credit card checking, e
-
commerce
and Electronic fund transfer are possible.


Easily administered.


Provides an efficient means of
communication such as e
-
mail, voice mail,
and video conferencing.


Provides data security.


IP sub netting


IP address


Is a unique address (number) to identify
each network devices.


Is 32 bit binary number with 4 octal


Ex:192.168.2.4


There is two parts in an ip address


Network part


Host part


IP sub netting cont…….


IP Classes


Class A


1.0.0.1


126.255.255.254


Class B


128.0.0.1
-
191.255.255.254


Class C


192.0.1.1
-
223.255.255.254

IP sub netting cont…….


Sub net mask


We can get subnet mark for a ip
number by each network bit value set to
1.


It helps to identify whether the network
is sub netted or not.


Ex: subnet mask for a class C ip is
255.255.255.0


Purposes of sub netting.


Eliminate ip wast


Fine tune network by utilizing ip in
efficient manner.





IP sub netting cont…….


Ex:


You have an ip ranage 192.168.1.0/24.
there is two labs to network with 50 and 25
terminals.




References.


Tanebaum, Andrew S.,2003,Computer
networks
-

2003
-
Pearson Education ;
Delhi
-

xx,891 p. : 4th ed. (modified on
19/04/2010)


Meijer,Anton,1982,Computer network
architectures
-
Computer Science Press ;
Maryland
-

xi,396 p. (modified on
19/04/2010)

Thank you!!!!!!!!!!!!!