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!efinitions

"n arrangement of two or interconnected

computers is called as computer network#

$hy computer network%%%%%

'hare the Information

(# )imited resources

*# To share the resources+# ost reduction


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ey Issues for omputer

Network

Nature of the node - .omogeneous or

.eterogeneous

(# Interconnection type - point to point or multipoint

*# /eliability

+# hannel capacity

0# 1rotocols

2# 1erformance

3# ontrol - centrali4ed, .ierarchical or !istributed


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Network omponents

5 Media – Physical or wireless media, Radio

wave, Microwave or satellite.5 Processor - Front end processor, client sever,

modem or routers.5 Software – Communication s/w, networin!

operatin! system5 "opolo!y – Physical arran!ement of Computers.

Star, Rin!, Mesh and tree5 #rchitecture – $S% Model or %&&&


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"dvantages of networking

5 onnectivity and ommunication5 !ata 'haring5 .ardware 'haring

5 Internet "ccess5 Internet "ccess 'haring5 !ata 'ecurity and 6anagement5 1erformance 7nhancement and 8alancing5 7ntertainment


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'isadvanta!es

Network .ardware, 'oftware and 'etup osts .ardware and 'oftware 6anagement and "dministration

osts 9ndesirable 'haring

Illegal or 9ndesirable 8ehavior !ata 'ecurity oncerns and privacy rash


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Network "rchitecture

6ainly ( types of architecture

1eer to 1eer architecture

(# lient server architecture#


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1eerto peer network

" peertopeer network is a network where thecomputers act as both workstations and servers#

In a strict peertopeer networking setup, everycomputer is an equal, a peer in the network#

7ach machine can have resources that are sharedwith any other machine#

There is no assigned role for any particular device,and each of the devices usually runs similar software#

"ny device can and will send requests to any other# great for small, simple, and ine;pensive networks# heapest to install 8est of small network &< to (< computers can be

linked together


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1eerto peer network =cont##>


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lient and 'erver computer role in

networking

Server- computer is acore component of thenetwork, providing a link tothe resources necessary toperform any task#

" server computer providesa link to the resourcesnecessary to perform anytask#

The link it provides couldbe to a resource e;isting onthe server itself or aresource on a clientcomputer#

Client computersnormally request and

receive information over

the network client# lient

computers also dependsprimarily on the central

server for processing

activities


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Client/Server (etworin!

In this design, a small number of

computers are designated as centrali4ed

servers and given the task of providing

services to a larger number of usermachines called clients

'erver: fulfill the request of the client

lient : always request to the server


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Client/Server (etworin! )cont..*


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Types of Networks

)"N =)ocal "rea Network>

6"N =6etropolitan "rea Network>

$"N =$ide "rea Network>Internet

Intranet

7;tranet$orld $ide $eb


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)ocal "rea Network =)"N>

Two or more computers directly linked within small definedarea such as room, building or group of closely placedbuilding#

)"N can made up of only microcomputers any combination

of microcomputers and large systems#

9nder the control of private owner

9sually connect with the 1hysical cable like coa;ial, fiberoptic cable#

ost of setting up is )ow, )ow error rate, /eliable, simple

maintenance and fle;ibility in growth#


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)O") "/7" N7T$O/ =)"N>


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6etropolitan "rea Network

=6"N>

6"N interconnects users with computer resources in a largegeographic area or region#

6"N network spanning a physical area larger than a )"N

but smaller than a $"N, such as a city# " 6"N is typicallyowned an operated by a single entity such as a government

body or large corporation#

6"N used to interconnect the several local area networks#

6"N cost of installation and operation is higher#

6"N use highspeed connections such as fiber optics to

achieve higher speeds#


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6etropolitan "rea Network

=6"N>


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$I!7 "/7" N7T$O/ =$"N>

$"N connects two or more computers that aregeographically dispersed by the wireless communicationchannel like telephone lines, radio waves, microwaves andsatellite#

$"N network crosses the communications links ofmetropolitan, regional, or national boundaries#

These use long distance telecommunication networks forconnection, thereby increasing the cost#

The Internet is a good e;ample of a $"N#


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$I!7 "/7" N7T$O/ =$"N>


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INT7/N7T

%("&R(&" is the network of networksthe largest network#

%("&R(&" is a global system of interconnected computer

networks#

%("&R(&" is not controlled by a central entity and thereforerelies on network devices and accepted conventions and

protocols to relay the data traffic until it gets to its

destinations#

7?: $"N best e;ample of internet


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INT7/"N7T

"n @intranet@ is the generic term for a collection of private

computer networks within an organi4ation#

"n AintranetB is a private network that is setup and controlled

by an organi4ation to

7ncourage interaction among its members,

(# To improve efficiency and to share information,

*# Organi4ational policies and procedures, announcements,

information about new products, and confidential data of

strategic value#

6any schools and nonprofit groups have deployed intranets,

but an intranet is still seen primarily as a corporate

productivity tool#


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INT7/N7TCINT/"N7T

The difference between an intranet and the Internet is

defined in terms of accessibility, si4e and control#

"ll the InternetDs content is accessible to everyone#

On the other hand an intranet is owned and controlled by a

single organi4ation that decides which members are

allowed access to certain parts of the intranet#

In general, an intranet is usually very small and is restricted

to the premises of a single organi4ation#


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7?T/"N7T

&+tranet "n A7;tranetB is an e;tended intranet#

In addition to allowing access to members of an

organi4ation, an e;tranet uses firewalls, access profiles,

and privacy protocols to allow access to users from outside

the organi4ation#

In essence, an e;tranet is a private network that uses

Internet protocols to securely share resources with

customers, suppliers, vendors, partners, or otherbusinesses#

ontdE#


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7?T/"N7T

"n A7;tranet@ is a computer network that allows controlled

access from the outside for specific business or educational

purposes#

%ntranets and &+tranets are communication tools

desi!ned to enale easy information sharin! within

wor!roups.


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$orld $ide $eb : $$$

Invented in &FGF by Tim 8erner)ee, 'wit4erland#

The $orld $ide $eb is a system of Internet 'erver#

Is the part of the Internet that contains websites and web

pages#

$ebsites and webpages are written in a markup languagecalled .T6) =.yperte;t 6arkup )anguage>

.T6) language supports links to other documents, as well

as graphics, audio, and video files#

This means you can jump from one document to anothersimply by clicking on the link#


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$orld $ide $eb

$ith the help of a web browser, one can view $eb

1age that may contain te;t, images, videos, and

other multimedia and navigate between them

via hyperlinks#

Not all Internet servers are part of the $orld $ide $eb#


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$eb browser

" browser is a software application used to locate, retrieve

and display content on the world wide web, including web

pages, images, video and other files#

"s a client server model, the browser is the client run on a

computer that contacts the $eb 'erver and requestsinformation#

The server sends the information back to the $eb browser

which displays the results on the computer or other

Internetenabled device that supports a browser#

The major web browsers are Hirefo;, Internet 7;plorer,

oogle hrome, Opera and 'afari#

Computer Network and Internet L3

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Transcript of Computer Network and Internet L3