CHAPTER - 10 COMPUTER NETWORKING INTRODUCTION
When two or more objects are connected they form a network. For example in our Vidyalaya all teachers form a network of teachers, all students form a network network of students and also in our home there is a family family network. Similarly Similarly in case of computer computer networks it is a collection collection of two or more computers. Network
It is a col colle lect ctio ion n of of int inter erco conne nnect cted ed auto autonom nomou ouss com compu pute ters rs..
Internet or Internetwork Abbreviation ! bbre!iation "# W# $# F%& S$%& I$& $'()$ WW W * &+ #FS %$" (%$ %%& %+& I& I& S"I& &&& SI$ /0 S$S )(0) )-mail #FS W""
It is a co ll llection of network s. s.
Full Form "ocal rea #etwork Wider rea #etwork $etropolitan rea #etwork File %ransfer &rotocol Simple $ail %ransfer &rotocol Internet $ail ccess &rotocol $odulator nd (emodulator World Wide Web *emote &rocedure +all #etwork File System yper %ext $arkup "anuae (ynamic yper %ext $arkup "anuae ypertext %ransfer &rotocol %ransmission +ontrol &rotocol Internet &r &rotocol Serial "ine Internet &rotocol &oint %o &oint &rotocol Subscribers Identification $odule /rd 0eneration of $obile +ommunication %echnoloy Short $essae Ser!ice )nhanced (ata rates for 0lobal )!olution Sendin 1 recei!in messaes el electronically #etwork File System Wireless "ocal "oop
+($ F* 0S$ *&#)% 2$" %$" 3*" IS& (#S VS#" $%#" WIS S"I& %+& %($ W($ F($ /0
"UE# "UE#TI TION ON PAT PATTE TERN RN "1(
+ode (i!ision $ultiple ccess Fixed *adio ccess 0lobal Switchin For $obile +ommunication d!anced *e *esearch &r &roject ency #e #etwork )xtensible $arkup "anuae ypertext $arkup "anuae 3niform *esource "ocater Internet Ser!ice &ro!ider (omain #ame System Videsh Sanchar #iam "imited $ahanaar #iam %elephone "imited Wide rea Information Ser!er Serial "ine Internet &rotocol %ransmission +ontrol &rotocol %ime (i!ision $ultiplexin Wa!elenth (i!ision $ultiplexin Fre4uency (i!ision $ultiplexin %hird 0eneration
$% No No "&e "&et tio ion' n'
company in *eliance has 5 wins of buildins as shown in the diaram6
+enter to center distances distances between between !arious 7uildins6 W/ to W8 W8 to W; W; to W5 W5 to W/ W/ to W; W8 to w5
9:m <:m ;9m 8=:m 8;9m >:m
#umber of computers in each of the win6 W8 W8 89: W; 89 W/ 89 W5 ;9
+omputers in each win are networked but wins are not networked. %he company has now decided to connect the wins also. i? Suest a most suitable cable layout of the connection between the wins. ii? Suest the most suitable win to house the ser!er of this company with a suitable reason. iii? Suest the placement of the followin de!ices with justification6 8? Internet connectin de!ice1modem ;? Switch 1 ub i!? %he company is plannin to link its head office situated in India with the offices at *eliance. *eliance. Suest an an economic economic way way to connect [email protected]
the the company company is ready to compromise on the speed of connecti!ity. Austify your answer.
Mot I)*ortant Note A**+i,ab+e to A++ "&etion bae on t.e above *atern/ w.i,. )a be ke*t in )in i? ii? iii? i!?
In a Win Win 1 7lock 7lock 1 "ab "ab conne connect ct all all comput computers ers usin usin a 37 37 or SWI% SWI%+. +. %his %his is known known as as "# connec connecti! ti!ity ity.. 7ut now now a day day we use SWI%+ only as it transmits data to the re4uired destination only and thus faster in transmission. +omputers +omputers in a 7lock 7lock are connected connected to the SWI%+ SWI%+13 137 7 usin usin +at 9 +able. +able. In place place of of +at 9 +able +able we can also also use use Fibre Fibre 'ptics 'ptics cable cable if we re4uire more speed and can afford cost. Ser!er Ser!er is placed placed where where there there is is maximum maximum number number of computers computers as as maximum maximum traffic traffic will be be in this this block only. n addition additional al switch switch may also also be used used to connec connectt the blocks blocks switch switches es for faster faster transmissi transmission on of data data and this this is also also placed placed in the block block where we ha!e put the ser!er. ser!er. %hese switches can be connected connected to the additional switch usin fibre optics since it will will increase speed but cost has to be born. If the comp company any desir desires es to ha!e ha!e connect connecti!i i!ity ty to the Inter Internet net,, Interne Internett connect connection ion is taken taken and and connect connected ed to switch switch.. From From here all all other other buildins and further computers can access the Internet connection. If the +ompany wants to connect these blocks to their office in some other distant place then we can connect these blocks with that office usin an Internet +onnection, *adio Wa!e +onnection Bif office is in hilly area?, W# connection connection if company can afford cost and re4uires re4uires security of data also. When W# connecti!ity is established, established, switch
is further further connected connected to a *'3%)*. *'3%)*. *outer is costly costly and filters filters the network traffic traffic.. It routers routers the data to the destinations destinations usin most optimal path. +onnecti!i +onnecti!ity ty between between the the blocks blocks switche switchess is done done usin +at 9 cable cables. s. If there there is a distance distance of more than than 8:: m between between any any two blocks blocks then a suitable *)&)%)* has to be placed to join +at 9 cables as in a "# we can use +at 9 cable up to a maximum lenth of 8:: m as the sinal power attenuates with more distances. So *)&)%)* is used to reenerate the sinal.
#o kee*in2 in )in t.e above *re&)*tion we anwer i? C we will use +at 9 cable to connect all the wins but in addition to this we will use a *)&)%)* in between the cable when connectin W5 to W/ as distance is 8=:m and W/ to W; as distance is 8;9m. ii? $ost suitable win to house the ser!er is Win W8as number of computers in this win is more. Blways remember that Ser!er Ser!er is placed in the Win where there is maximum number of computers?. iii? +omputer 1 nodes 1 workstations in a "ab 1 Win are not connected to each other directly. directly. %hey are first connected to either a SWI%+ SWI%+ or 37 usin +at 9 cable. %hen this SWI%+ 1 37 is i!en power supply and then "# works. +onnectin of computers 1 nodes 1 workstations workstations in a "ab is known as "# B"ocal rea #etwork?. 7ut always connect these de!ices with a SWI%+ since its performance is better than a 37 with reference to transmission of data. Internet connectin de!ice 1 modem is to be connected to SWI%+ only in that "ab 1 Win where there is a maximum number of computers. From this switch Internet Internet connectin can work in all the other labs. Internet connection can can also be connected to Ser!er Ser!er but then we ha!e to use the Windows Share proram to share Internet connection amon other computers. i!? +ompanys offices can be connected C Ba? Ba? Bb? Bb?
by Inte Interne rnett conne connecti ction on but but then then it will will ha!e ha!e to compro compromis misee on securi security ty of of data data and speed speed of tra transmi nsmissi ssion. on. %he %he oth other er way way is is usi usin n a W# W# conn connec ecti tion on.. It will will be cost costly ly,, secu secure re and and spe speed edie ier. r.
In our case the company can compromise on speed. So it can use Internet +onnection as it can be cheaper cheaper as its chares could be fixed or as per usae. "3( Dnowlede supplement 'raniEation has set up its new center at $analore for its office and web based acti!ities. It has 5 7locks of buildins as shown in the diaram below6
7loc k+ 7loc k(
+ent +enteer to to ce cente nter di distan stancce bet betwe ween en !ar !arious ious bloc blocks ks
#um #umber ber of of +om +ompu putters ers
7lock to 7lock 7
7lock 7 to 7lock +
7lock + to 7lock (
7lock to 7lock (
7lock 7 to 7lock (
7lock to 7lock +
Suest a most suitable cable layout of connections between the 7locks. Sues Suestt the the most most suitab suitable le plac places es Bi.e Bi.e.. 7lock 7lock?? to to house house the ser!er ser!er of this this orani oraniEa Eatio tion n with with a suitab suitable le reason reason..
Suest the placement of the followin de!ices with justification6 a. *epeat *epeater er b. ub1Sw ub1Switc itch h i!. %he ora oraniE niEati ation on is plann plannin in to to link link its head head offi office ce situa situated ted in in +ity +ity in a hilly hilly rei reion on where where cabl cablee connec connectio tion n is not feas feasibl ible, e, sue suest st an economic way to connect it with reasonably hih speed
AN# - i? +at 9 +able for connectin 7locks and usin a *)&)%)* *)&)%)* between 7 and +, 7 and (, and ( and also between and + Bsince it is just near to 8::? *)&)%)*S for reeneratin sinal and +at 9 for transferrin data between blocks and it is n etworkin cable.
ii? Suitable place to house ser!er is 7lock + where 8;9 +omputers are to be placed. iii? *)&)%) *)&)%)* * between between blocks 7 and +, 7 and (, and ( and and + for reenerat reeneratin in sinal. sinal. SWI%+)S SWI%+)S 1 37 in each block to connect connect the +omputers on "#. i!? *(I' WV) transmissi transmission on link to connect to office in hilly area as these wa!es can tra!el lon distance, penetrate penetrate in buildins and also omni directional. #'%) C for layout etc you ha!e draw a diaram of the blocks also and place suitable *)&)%)*S in between the blocks ha!in lon distance and also place SWI%+ 1 37 in the 7locks.
Indian Industries has the followin four buildins buildins in +hennai. (istance between !arious wins is i!en below6 below6 II8 II ;
Wins "ayout &lans Win II8 to Win II / =:m Win II8 to Win II ; ;:m Win II II 8 to Wi Win II II 5 88 9m 9m Win II / to Win II 5 /:m Win II ; to Win II/ ;9m
#o of +omputers in each Win
Win II 8 Win II ; Win II / Win II 5
i? ii? iii? i!? AN#
/9 ;9 H: <:
Suest Suest suitable suitable +7") +7") "G'3%S "G'3%S F'* %)S) %)S) 73I"( 73I"(I#0S I#0S.. #ame the win where the Ser!er Ser!er is to be installed. Austify your answer. Suest the placement placement of ub1Switch ub1Switch in the network. $ention an economic technoloy technoloy to pro!ide Internet Internet accessibility to all all wins. i? (raw diaram of the wins with +at 9 +able placin *)&)%)*S between Wins II8 and II5 as there is more than 8:: m distance. ii? Ser!er to be installed in Win II/ as it has maximum number of computers. iii? SWI%+ 1 37 is to be placed in each Win to connect them in "# and further these SWI%+)S are to be connected to another SWI%+. %his may be placed in Win II/. i!? 7roadband connection as it is cheaper in the SWI%+ which is connectin all Wins Switches and from here all the wins can access it.
Fi 6 #)%W'*DI#0 +'#+)&% +'#+)&%
+onnection of ; or more distinct Bpossibly dissimilar? networks. *e4uires some kind of network de!ice to facilitate faci litate facili tate the connection.
T6PE# 7 MODE5# O8 NETWORK#
"# C "ocal rea #etwork $# C $etropolitan rea #etwork W# C Wider rea #etwork 5o,a+ Area Network connects computers that are physically close toether B 8 mile?. Chih speed Cmulti-access
%echnoloies6 C)thernet 8: $bps, 8::$bps C%oken *in 8< $bps CF((I 8:: $bps Wier Area Network connects computers that are physically far apart. Jlon-haul networkK. -typically slower than a "#. Ctypically less reliable than a "#. "#. Cpoint-to-point
%echnoloies6 Ctelephone lines CSatellite communications -microwa!e 1 radio wa!e links Metro*o+itan Area Network
"arer than a "# and smaller than a W# - example6 campus-wide network - multi-access network %echnoloies6 Ccoaxial cable Cmicrowa!e
%opoloies refer to the techni4ues techni4ues 1 ways of inter connectin connectin computers or networks. $eans how the computers computers and networks are connected connected to each other. %hese can be connected in the followin followin ways C Rin2 To*o+o2 i? +omm +ommun unic icat atio ion n is is one one way way in this this topo topolo loy y.. %he %he spe speed ed is is slow slow.. ii? token token which carries carries the data carry carry on runnin runnin in the rin. 'nly one node communicat communicates es at at a time. iii? #ode for for which which the data data is is attached attached to the token token capture capturess the token token and and after after usin data relea releases ses it on on the rin. rin. i!? i!? "ike "ike this this the the rin rin carr carry y on on mo! mo!in in. . !? If one node node becom becomes es unse unser!i r!icea ceable ble,, the the whol wholee rin rin #W #W is crashe crashed. d. 9& 7 #eria+ To*o+o2 i? ll nodes nodes are are conn connect ected ed to to a strai straiht ht wire wire Bthin Bthinnet net of coax coaxial ial cable? cable?.. Speed Speed is is slow. slow. ii? ii? 'nly 'nly one one node node can can com commu muni nica cate te at a tim time. e. iii? +ommunicat +ommunication ion is both both directi directional onal but at a time time data data can pass pass only in in one direct direction. ion. t the other end of the bus the sinal sinal is discarded. discarded. i!? If one one node is is unser!i unser!icea ceable ble,, network network past past of that that node node become becomess unser!i unser!icea ceable ble..
#tar 7 Raia+ To*o+o2 i? #odes odes are atta attacched hed to to a 37 1 SWI SWI% %+ ii? #etwork is faster. iii? iii? It is most most wide widely ly used used topo topolo loy y i!? If one node becomes becomes unser! unser!icea iceable, ble, the other nodes in in the network network are are not affec affected ted all other nodes nodes carry carry on on recei!in recei!in inform information ation.. 'nly that node is out of network.
$esh %opoloy %ree %opoloy &oint to &oint 0raph
NETWORKING TECHNI"UE# Peer to Peer C )ach node in the network is ha!in its own resources 1 processin capabilities. It may sh are information amon others. #odes may not ha!e to depend upon others for carryin out their work. )ach node its own master i.e. has no boss. %hey are independent independent and work the way they like. C+ient #erver $C7#' C In this techni4ue there is one dedicated dedicated boss that is known as ser!er. Whole the network works under the ser!er and it has full control on all all the nodes. 7oss is is known as $aster $aster 1 Ser!er. %he other nodes which are controlled controlled by Ser!er are are known as Sla!es 1 +lients. +lients send re4uest to the ser!er and the ser!er recei!es their re4uests and reply.
i? ii? iii? i!?
ub Switch *epeater 7rides
!? !i ? !ii? !iii? ix?
*outer 0ateways *A 59 59 +onnector #I+ C #etwork #etwork Interface Interface +ard +ard 1 )thernet )thernet +ard 1 "# +ard B5H bit $+ $+ ddr '3I-'ra '3I-'raniEat niEational ionally ly 3ni4ue Identifi Identifier? er? $odem
MODE O8 COMMUNICATION# $8U55 DUP5E; :# HA58 DUP5E;' 8&++-D&*+e< ser!ices support the transfer of data in both directions.
Ha+=-D&*+e< ser!ices support the transfer of data in a sinle direction.
NEED 7 9ENE8IT# O8 A NETWORK
-%o share resources in network -(ecrease costs of transfer -Increase speed in transferrin -Impro!es communication Tran)iion Meia 7 C.anne+ o= Co))&ni,ation
%ransmission media is used to establish connecti!ity between computers or networks. %wo %ypes of transmission media G&ie Meia - in this type connectin cables are the communication communication channels between the different different works stations. Na)e Ientit
Twite Pair Cab+e Coa<ia+ Cab+e 'rdin rdinaary )lectr ectric ical al +abl +ablee %V wire wire
O*ti,a+ 8ibre Cab+e hih hih spee peed wire ire ha!i ha!in n thin hin la lass
Conne,tor #*ee Ditan,e Cot T*e
Wire *A 59 8:: C 8::: mbps 8:: meters +heapest S%& L 3&%
Un2&ie Meia sinal.
7#+ 8: mbps 9:: meters +heaper %hinnet 1 %hicknet
pipe in it. S+ 1 S% 8::: mbps - i iabits 8:: km +ostly S$ 1 $$
in this this there there is no no direct direct conne connecti ction on betwee between n the sourc sourcee 1 destina destinatio tion n worksta workstatio tions ns and some some wa!e wa!ess are used used to to transm transmit it the
$icrowa!e *adio Wa!e Satellite Infrared wa!es Data Co))&ni,ation Ter)ino+o2ie
(ata +hannel C is a medium used to carry information 1 data from one point to another point. 7aud 1 7aud 7aud *ate C it the measure measurement ment unit unit of data carry carryin in capacity capacity of a data channel channel bps bps is bits per second transmitted on a data channel channel 7ps 7ytes per second transmitted. 7andwidth C it is amount of information tra!elin throuh a sinle channel at any point of time.
Data Tran)iion #wit,.in2 Te,.ni>&e 7 How t.e in=or)ation i .are 7 Tran=erre in a NW
Information transferred from one node to another node in a network is known as switchin. Switchin takes places in the followin ways C Cir,&it #wit,.in2
- ex %elephone line. In this source is connected to destination destination from end to end.
Mea2e #wit,.in2 - ex )-mails. 3ses store and forward forward technoloy for transfer of information. information.
Source sends information that is recei!ed by its nearby switch office. office. %his switch office sends the information to another switch switch office and that further forwards to another switch office until the whole information information is reached at the switch office that is nearer to the destination. destination. %hen this switch officer forwards information to the destination. Pa,ket #wit,.in2
- %his techni4ue also uses store and forward techni4ue but the data is broken into smaller siEe parts which are known as packets.
&rotocols are the set of rules rules that o!ern the communication o!er a network. Some important protocols are C %+& 1 I& C Tran)iion Contro+ Proto,o+. %his protocol establishes reliable or unreliable connection between between the source and destination. It also breaks the data into sements. I& C Internet Proto,o+. %his protocol is responsible for pro!idin #etwork ddress 1 I& ddress of the destination network. I& ddress is /; bit address. I& ddress is di!ided into #etwork ddress and ost ddress. %%& C ypertext %ransfer &rotocol &rotocol - It allows different types of computers 1 #etworks to establish communication between them. It has two features C re4uests re4uests and responses.
DI88ERENCE 9ETWEEN WIRE5E## 7 MO9I5E Wire+e is without use of wire Bland line 1 physical connection?. Mobi+e - %he de!ice de!ice is in touch with the data source source continuousl continuously y without without physical physical connection connection.. It satellite or laser etc.
:ieo Con=eren,in2 - It is sounds, !ideo, talkin and !iewin o!er internet communication. We need Internet connection, connection, &+ +amera and its its Software, !ideophone Software B#et $eetin? for !ideo conferencin. WWW C World Wide Web is a protocol that allows allows to access documents on the internet. Web Pa2e C document on the net is called a web pae. pae.
UR5 C )ach web pae has an address that is is called 3*". 3niform *esource "ocator. "ocator. H*erte<t C %he contents of a web pae is called called ypertext. It can be audio, !ideo, text, raphic and e!en H*er+ink
link to some other pae.
"ink "ink to some some othe otherr pa paee in in a web web pa paee is is cal calle led d yp yper erli link nk..
Te+net C %erminal )mulation. It is a proram proram that is used to remotely loin network ser!er 1 de!ices. Web 9rower- It is a proram that is used to na!iate throuh the web paes and display their contents. )x Internet )xplorer, )xplorer, #etscape #a!iator #a!iator and $oEilla etc Web #erver C www ser!er that responds responds to the re4uests made by web browsers. Web #ite C location on a web ser!er is called called a web site. It contains web paes and has a uni4ue address. %his address is called 3*".
used to de!elop web paes. HTM5 C ypertext $arkup "anuae C used Web Hotin2 C ostin of web ser!er application application on a computer. Network #e,&rit
s we ha!e seen that the #W offers offers a lare number of benefits. %hese benefits are prone to threats. threats. #W security means to counter such threats threats to the #W. Met.o o= NW #e,&rit
uthentication C i!in passwords etc uthoriEation C only the users loin 7iometric Systems C scan retina 1 (# etc Firewall C pre!ents unauthoriEed access to 1 from a pri!ate network. Cookie C It is a messae sent by web ser!er to the web web browser so that it can keep tract tract of users acti!ities on a specific specific web site. Cra,ker C seek entry to alien #W with the indention to harm them. them.
Ha,ker C seek entry to the alien #W with the intention intention to just ha!e entry without harmin them.