computer networks it (1)

7/23/2019 Computer Networks IT (1)

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PRESENTATION ON

COMPUTER NETWORKS


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COMPUTER NETWORKA computer network, or simply network, is

collection o! computers n" network #r"wreinterconnecte" $y communiction c#nnels

t#t llow s#rin% o! resources n"

in!ormtion&


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NETWORK ARCHITECTURE

Network rc#itecte" is t#e o'erll "esi%n o!

computer network t#t "escri$es #ow t#e

computer network is con!i%ure"&

Network rc#itecture is t#e "esi%n o!

communictions network&

Also clle" network mo"el or network "esi%n


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COMPUTER ARC(ITECTURE

T#ere re two types o! network mo"els& T#ey re )

PEER TO PEER ARC(ITEC(ER

C*IENT SER+ER ARC(ITEC(ER


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PEER TO PEER MOE*

A peer-to-peer computer network is one

in w#ic# ec# computer in t#e network

cn ct s client or ser'er !or t#e ot#ercomputers in t#e network, llowin%

s#re" ccess to 'rious resources suc#

s !iles, perip#erls, n" sensors wit#outt#e nee" !or centrl ser'er&
http://en.wikipedia.org/wiki/Peripheralhttp://en.wikipedia.org/wiki/Peripheral


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C*IENT SER+ER MOE*

In t#is type o! network, one computer ct s

ser'er t#t pro'i"es ser'ices to ot#er

computers .client/ on network re0uest ser'ice

!rom t#e ser'er&

A ser'er is computer t#t controls cesses to

#r"wre, so!twre etc&

A client is computer t#t re0uest !or ser'ices

!rom t#e ser'er&


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COMPARISON

C*IENT1SER+ER Ser'er #s t#e control $ility

,w#ic# client "oes not

(i%# c$le cost

Esy to mn%e

It is use" in Smll 2 lr%e

networks

Instll So!twre only in t#e

ser'er, w#ile clients s#re t#eso!twre

One power!ul computer ctin% s

t#e ser'er

PEER TO PEER All computer #s e0ul $ility

C#eep C$le cost

(r" to Mn%e Normlly use" in smll networks

wit#345 computers

Instll so!twre to e'ery

Computer

No ser'er is nee"e"


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A+ANTA6ES O7 A NETWORK

7ile s#rin%

Resource s#rin%

Ine8pensi'e setup 7le8i$le #n"lin%

Increse stor%e cpcity


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ISA+ANTA6ES O7 NETWORK

Security concerns

+irus n" mlwre

*ck o! ro$ustness Nee" e!!ecti'e #n"ler

*ck o! in"epen"ence


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NETWORK TOPO*O69

A network topolo%y is t#e lyout

o! interconnecte" no"es o! computer network.


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ISA+ANTA6ES O7 RIN6 TOPO*O69

T#e !ilure o! sin%le no"e o! t#e

network cn cuse t#e entire network

to !il& T#e mo'ement or c#n%es m"e to

network no"es !!ects t#e

per!ormnce o! t#e entire network&


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MES( NETWORK)

Ec# no"e is connecte" to nr$itrry num$er o! nei%#$ours

in suc# wy t#t t#ere is t

lest one tr'ersl !rom nyno"e to ny ot#er.


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MES( TOPO*O69

A+ANTA6E

T#e rrn%ement o! t#e network no"es is suc# t#t

it is possi$le to trnsmit "t !rom one no"e to

mny ot#er no"es t t#e sme time&

ISA+ANTA6E

T#e rrn%ement w#erein e'ery network no"e is

connecte" to e'ery ot#er no"e o! t#e network,mny o! t#e connections ser'e no m:or purpose&

T#is le"s to t#e re"un"ncy o! mny o! t#e

network connections&


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NETWORK MOE*

TCP1IP MOE*OSI -; *A9ERMOE*


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1. Link Layer

the coaxial cables, twisted pair wires, the optical fber,interace cards, etc., are a part o this layer

It explains how the data is transmitted rom the host,

through the network.

, this layer includes the physical and logical

connections rom the host's link2. Internet Layer

his layer is also known as the !etwork Layer. he

main unction o this layer is to route the data to its

destination. he data that is recei"ed by the link layer

is made into data packets #I$ datagrams%. he data

packets contain the source and the destination I$

address or logical address

TCP1IP MOE*


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&. pplication Layer

It pro"ides the user interace or

communication. his is the layer where email,

web browsers or ($ run.

). ransport Layer

his layer allows the host and the destination

de"ices to communicate with each other or

exchanging messages, irrespecti"e o the

underlying network type


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+I - L/0 +30L#+$0!

/0 I!04+!!0403%

1.3ata Link Layer

he main unction o this layer is to

con"ert the data packets recei"ed romthe upper layer into rames, and route

the same to the physical layer

2. !etwork Layer

he main unction o this layer is to

translate the network address into

physical 4 address. he data has to


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&. ransport Layer

his layer pro"ides end-to-end

deli"ery o data between two nodes.

It di"ides data into di5erent packets

beore transmitting it.

). ession Layer

his layer is responsible to establish

and terminate connections between

two communicating machines


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6.$resentation Layer

he data con"ersion takes place at

this layer. he data that it recei"es

rom the application layer is

con"erted into a suitable ormat that

is recogni7ed by the computer

8. pplication Layer

his layer pro"ides a user interace

by interacting with the running


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. $hysical Layer

s the name suggests, this isthe layer where the physicalconnection between twocomputers takes place.


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*OCA* AREA NETWORK

.


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*OCA* AREA NETWORK .*AN/

*AN is term use" to "escri$e interconnecte" computersn" perip#erls t#t re in close pro8imity&

It is computer networkt#t interconnects computers in limite" re suc# s #ome, sc#ool, computerl$ortory, or o!!ice $uil"in% usin% network me"i&

Consists o! :ust two or t#ree PCs connecte" to%et#er to

s#re resources, or my inclu"e 455s o! computers o!"i!!erent kin"s&
http://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/Computer_network


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*AN

Any network t#t e8ists in sin%le $uil"in%, or

e'en in %roup o! ":cent $uil"in%s , is

consi"ere" s *AN&

It is not system t#t connects to t#e pu$lic

en'ironment like internet usin% p#one or "t

lines&


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*AN IN OR6ANISATIONS

It is o!ten #elp!ul to connect seprte *ANs to%et#er sot#t t#ey cn communicte n" e8c#n%e "t&

In lr%e compnies, sy two "eprtments locte" on t#esme !loor o! $uil"in% my #'e seprte *ANs,$ut i!t#e "eprtments nee" to s#re "t, t#ey cn crete link$etween two *ANs&

Wit# *AN, top mn%ement cn coor"inte n" control

opertions e'en t#ou%# processin% tkes plce t"i!!erent plces&


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LAN- ADVANTAGES

Worksttions cn s#re perip#erl "e'ices like printers& T#is is c#epert#n $uyin% printer !or e'ery worksttions&

Worksttions "o not necessrily nee" t#eir own #r" "isk or C-ROM"ri'es, w#ic# mkes t#em c#eper to $uy t#n stn"-lone PCs&

User cn s'e t#eir work centrlly on t#e network


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LAN- DISADVANTAGES

Networks re "i!!icult to set up n" nee" to $e mintine" $y skille"tec#nicins&

I! ser'er "e'elops !ult, users my not $e $le to run t#e pplictionpro%rms&

A !ult in t#e network cn cuse user to lose t#e "t&I! t#e network stops opertin% t#en it my not $e possi$le to ccess 'riouscomputers&

It is "i!!icult to mke t#e system secure !rom #ckers, or in"ustril espion%e& ecisions on resource plnnin% ten" to $ecome centrli=e"&

Networks t#t #'e %rown wit# little t#ou%#t cn $e ine!!icient in t#e lon%term&

As tr!!ic increses on network t#e per!ormnce "e%r"es unless it is"esi%ne" properly&

T#e lr%er t#e network, t#e more "i!!icult is to mn%e&


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WAN

.WIE AREA NETWORK/


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WIE AREA NETWORK

It is telecommunictions network &

Usully !orme" $y interconnectin% multiple *AN>s o! "i!!erent

or%nistion&

WAN spns cross lr%e %eo%rp#icl re suc# s countries

2 continents&

WAN>s re o!ten use" $y lr%er corportions1 or%ni=tion to

!cilittes t#e e8c#n%e o! "t&

T#e lr%est n" most well known e8mple o! WAN is

INTERNET&


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T#e "t trnsmission rte in WAN>s usully rn%es !rom 4?55$its1sec

-?M$ps&

t trnsmission errors re more compre" to *AN&

Communiction links use" in WAN>s re Telep#one lines, microw'e links2stellite c#nnels&

T#e cost o! "t trnsmission my $e 'ery #i%# $ecuse t#e trnsmission

me"i use" re lese" lines1pu$lic communiction systems&

T#e ARPANETws t#e !irst WAN&

ERNET .E"uction n" Reserc# Network/ is WAN, w#ic# links se'erl

e"uction 2 reserc# institutions in In"i&


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A+ANTA6ES

Co'ers lr%e %eo%rp#icl re so lon% "istnce $usinesses

cn connect on t#e one network&

S#res so!twre n" resources wit# connectin% worksttions&

Mess%es cn $e sent 'ery 0uickly to nyone else on t#e

network& T#ese mess%es cn #'e pictures, soun"s, or "t

inclu"e" wit# t#em .ttc#ments).


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CONTINUE...

E8pensi'e t#in%s .suc# s printers or p#one lines to t#e internet/ cn $e s#re" $yll t#e computers on t#e network wit#out #'in% to $uy "i!!erent

perip#erl !or ec# computer&

E'eryone on t#e network cn use t#e sme "t& T#is 'oi"s pro$lems

w#ere some users my #'e ol"er in!ormtion t#n ot#ers&

S#re in!ormtion1!iles o'er lr%er re&

lr%e network co'er&


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ISA+ANTA6ES

Are e8pensi'e n" %enerlly slow&

Nee" %oo" !irewll to restrict outsi"ers !rom enterin% n" "isruptin% t#e

network&

Settin% up network cn $e n e8pensi'e n" complicte" e8perience& T#e$i%%er t#e network t#e more e8pensi'e it is&

Security is rel issue w#en mny "i!!erent people #'e t#e $ility to use

in!ormtion !rom ot#er computers& Protection %inst #ckers n" 'iruses""s more comple8ity n" e8pense&


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CHARACTERISTICS OF WAN

1. Communication Faciit!"

Fo# a $i% com&an! '&annin% o(# *i++#nt &a#t' o+ t, count#! t,

m&o!' can 'a( on% *i'tanc &,on ca' an* it o(#com' t, tim a%

in o(#'a' communication'. Com&ut# con+#ncin% i' anot,# u' o+ WAN

,# u'#' communicat it, ac, ot,# t,#ou%, t,i# com&ut# '!'tm.

. Rmot Data Ent#!"

Rmot *ata nt#! i' &o''i$ in WAN. It man' 'ittin% at an! ocation

!ou can nt# *ata/ u&*at *ata an* 0u#! ot,# in+o#mation o+ an! com&ut#attac,* to t, WAN $ut ocat* in ot,# citi'. Fo# am&/ 'u&&o' !ou a#

'ittin% at 2a*#a' an* ant to ' 'om *ata o+ a com&ut# ocat* at D,i/

!ou can *o it t,#ou%, WAN.


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@& Centrlise" In!ormtion)

In mo"ern computerise" en'ironment you will !in"

t#t $i% or%nistions %o !or centrlise" "t stor%e& T#is

mens i! t#e or%nistion is spre" o'er mny cities, t#ey

keep t#eir importnt $usiness "t in sin%le plce& As t#e

"t re %enerte" t "i!!erent sites, WAN permits collection

o! t#is "t !rom "i!!erent sites n" s'e t sin%le site.


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CONC*USIONcomputer Network is t#e network

collection o! computers ment !or

s#rin% t#e in!ormtion n" resources

Peer to peer ,ser'or networksi!!erent topolo%ies


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T,an3!ou

computer networks it (1)

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