CH01 Introduction to Data Communications

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Copyright 2011John Wiley & Sons, Inc. 1 - 1

Business Data Communicationsand Networking

11th Edition

Jerry Fitzgerald and Alan Dennis

John Wiley & ons! "nc

Dwayne Whitten, D.B.A

ays B!siness School

"e#as A& $ni%ersity




Cha#ter 1

Introduction to Data

Communications



Copyright 2011John Wiley & Sons, Inc. 1 -

Cha#ter 1 $utline

1.1 ' Intro(!ction – Brie) history o) Data Co**!nications, Co**!nications, In)or*ation

Syste*s an( the Internet

1.2 - Data Co**!nications +etwors

– +etwor co*ponents, networ types

1. - +etwor o(els – SI *o(el, Internet *o(el, trans*ission %ia layers/

1. - +etwor Stan(ar(s

– Stan(ar(s *aing, co**on stan(ar(s

1. - !t!re "ren(s

– 3er%asi%e networing, integration o) %oice, %i(eo, an( (ata, newin)or*ation ser%ices

1.4 ' I*plications )or anage*ent



1%1 "ntroduction





"normation Age

• irst In(!strial 5e%ol!tion – Intro(!ction o) *achinery

– +ew organi6ational *etho(s

– Change( the way people wore(

• Secon( In(!strial 5e%ol!tion ' In)or*ation Age

– Intro(!ction o) co*p!ters

– Intro(!ction o) networing an( (ata co**!nication

– Change( the way people wore( again

• aster co**!nication Collapsing In)or*ation lag

• Bro!ght people together 7lo8ali6ation




'he Colla#sing "normation (ag

1900 190 20091:0

large ;!antities o)in)or*ation trans*itte( ina )raction o) a secon(

telegraph

In)or*ation too (ays

or wees to 8e

trans*itte(

In)or*ation

trans*itte( in *in!tes

or ho!rs

<istorical (e%elop*ents inelectronic co**!nications

spe( !p the rate an( %ol!*e o)

trans*ission o) in)or*ation

growth o) teleco**!nications an(especially co*p!ter networs 7lo8ali6ation

o) networs



Copyright 2011John Wiley & Sons, Inc. 1 - =

'hree )arts to *nderstanding

Networking

1. Concepts of networking – <ow (ata *o%es )ro* one co*p!ter to another o%er a

networ

– "heories o) how networs operate

2. Technologies in use today – <ow theories are i*ple*ente(, speci)ic pro(!cts

– <ow (o they wor, their !se, applications

3. Management of networking technologies

– Sec!rity

– +etwor Design

– anaging the networ



Copyright 2011John Wiley & Sons, Inc. 1 - :

Ad+ances in )hone 'echnology

1:=4

3hone

in%ente(

)irst trans-continental

an(transatlantic

phoneconnections

191

1919

Strowger >stepper?switch,

rotary (ial phones

>ena8ling a!to*atic

connections?

19:

icrowa%e

tr!n lines

>Cana(a?

1942

"elstar>"eleco**!nications

%ia satellite?, a#ser%ices, (igitaltrans*ission >"-

carriers?

1949

3ict!re)one

>)aile(

co**ercially?

19=4

3acet-switche((ata

co**!nications

19:

Cell!lar

telephone




,egulation o "n+entions

1900

*illions o) phones

in !se in the $S

5eg!lation8egan in the$SA >ICC?

19

CC esta8lishe(

194:

Carter)one co!rt

(ecision allowing

non-Bell C3@

19=0

CI wins co!rt case

8egins pro%i(ing so*e

long (istance ser%ices

19:

Consent

(ecree 8y $S

)e(eral co!rt

1994

1994 $S

"eleco*

Act

A time fortechnologicalchange

1::

A"&"

3hone

in%ente( >rapi(

acceptance?

1:=4

Bell Syste*

(e )acto

*onopoly

1910

Deregulation

period




1-./ Consent Decree

Di%estit!re o) 11: 5BCs• AT&T broken up into one long distance company (AT&T and !

"egional #ell $perating Companies ("#$C%s

Dereg!lation IECs an( F@Cs• Competitie long distance (I'C market )CI & *print enter long

distance telephone market (among others

• +ocal ,-change Carrier (+,C serice markets remained under

"#$C monopoly




* 'elecom Act o 1--0

• "eplaced all current laws. /CC regulations.0123 consent decree. and oerrules state

laws

• )ain goal4 open local markets to competition• To date. though. local and long distance

competition slow to take hold

– +arge I'Cs e-pected to moe into the local

markets. happening only recently

– +ikewise. "#$Cs e-pected to moe into long

distance markets. happening only recently




Worldwide Com#etiti+e arkets

• Internet *aret – @#tre*ely co*petiti%e with *ore than 000 Internet

Ser%ice 3ro%i(ers >IS3s? in the $S alone.

– <ea%y co*petition in this area *ay lea( to a shae o!tin the near )!t!re.

• Worl( "ra(e rgani6ation >W"? agree*ent>199=?

– co**it*ents 8y 4: co!ntries to open, (ereg!late orlessen reg!lation in their teleco* *arets

• !lti-national teleco* co*panies – $S co*panies o))ering ser%ices in @!rope, So!th

A*erica

– @!ropean co*panies o))ering ser%ices in $SA




2istory o "normation ystems

Data co**!nications o%er

phone lines >8eca*e

co**on an( *ain)ra*es

8eca*e *!lti-!ser syste*s?

Batchprocessing*ain)ra*es

+etworinge%erywhere

3C FA+s

8eco*e

co**on

190 1940 1990 200019=0 19:0

nline real-ti*e,

transaction oriente(

syste*s >replace( 8atch

processing. DBSs

8eco*e co**on?

3C re%ol!tion




"nternet ilestones

riginally calle(A53A+@", the Internet8egan as a *ilitary-aca(e*ic networ

1949

Worl(wi(e%er 1 8illion

Internet !sers

200=1990

co**ercial

access to

the Internet

8egins

A53A+@" splits• ilnet - )or *ilitary• Internet - aca(e*ic,

e(!cation an( research

p!rposes only

19:

+S+et

create( as

$S Internet

8ac8one

19:4

7o%ern*ent

)!n(ing o) the

8ac8one

en(s

199



Net Neutrality


+et ne!trality *eans that )or a gi%en type o) content >i.e. e*ail,

we8, %i(eo, etc?, all content pro%i(ers are treate( the sa*e.

+et ne!trality pre%ents IS3s )ro* gi%ing priority to so*e content

pro%i(ers, while slowing (own others



con%ergence


1%3 Data Comm Networks

Broa(8an( Co**!nications

"eleco**!nications G"rans*ission o) %oice, %i(eo,an(or (ata

5 I*plies longer (istances

- Broa( ter*

Data Co**!nications Go%e*ent o) co*p!terin)or*ation 8y *eans o) electricalor optical trans*ission syste*s



Copyright 2011John Wiley & Sons, Inc. 1 - 1=

Com#onents o a (ocal Area Network



Copyright 2011John Wiley & Sons, Inc. 1 - 1:

Network 'y#es 45ased on cale6

• Focal Area +etwors >FA+? - roo*, 8!il(ing – a gro!p o) 3Cs that share a circ!it.

• Bac8one +etwors >B+? - less than )ew *s

– a high spee( 8ac8one lining together organi6ational FA+sat %ario!s locations.

• etropolitan Area +etwors >A+? - >*ore thana )ew *s?

– connects FA+s an( B+s across (i))erent locations

– )ten !ses lease( lines or other ser%ices !se( to trans*it

(ata.• Wi(e Area +etwors >WA+s? - >)ar greater than 10

*s?

– Sa*e as A+ e#cept wi(er scale




(ANs and Back5ones! Wide Area and

etro#olitan Area Networks




"ntranet +s% E7tranet

• Intranet – A FA+ that !ses the Internet technologies within an

organi6ation

– pen only those insi(e the organi6ation

– @#a*ple ins!rance relate( in)or*ation pro%i(e( toe*ployees o%er an intranet

• @#tranet

– A FA+ that !ses the Internet technologies across anorgani6ation incl!(ing so*e e#ternal constit!ents

– pen only those in%ite( !sers o!tsi(e the organi6ation

– Accessi8le thro!gh the Internet

– @#a*ple S!ppliers an( c!sto*ers accessing in%entoryin)or*ation in a co*pany o%er an e#tranet




(ayered "m#lementation o

Communications Functions

Applications

S

Applications

S

!lti layer

i*ple*entation5Breaing (own into

s*aller co*ponents5@asier to i*ple*ent

Single layeri*ple*entation-+etworing withlarge co*ponentsis co*ple# to!n(erstan( an(

i*ple*ent

Applications

S

C o

* *

! n i c

a t i

o n

Applications

S

C o

* *

! n i c

a t i

o n




1%8 ulti9layer Network odels

• "he two *ost i*portant s!ch networ *o(elsSI an( Internet

• pen Syste*s Interconnection o(el

– Create( 8y International Stan(ar(s rgani6ation >IS?

as a )ra*ewor )or co*p!ter networ stan(ar(s in 19: – Base( on = layers

• Internet o(el

– Create( 8y DA53A originally in early 19=0s

– De%elope( to sol%e to the pro8le* o) internetworing – Base( on layers

– Base( on "rans*ission Control 3rotocol Internet3rotocol >"C3I3? s!ite




:9(ayer odel o $"

• Application Fayer

– set o) !tilities !se( 8y application progra*s

• 3resentation Fayer

– )or*ats (ata )or presentation to the !ser

– pro%i(es (ata inter)aces, (ata co*pression an(

translation 8etween (i))erent (ata )or*ats

• Session Fayer

– initiates, *aintains an( ter*inates each logical session

8etween sen(er an( recei%er

“Please Do Not T ouch Steve’s Pet Alligators”3hysical DataFin +etwor "ransport Session 3resentation Application




:9(ayer odel o $"

• "ransport Fayer – (eals with en(-to-en( iss!es s!ch as seg*enting the

*essage )or networ transport, an( *aintaining thelogical connections 8etween sen(er an( recei%er

• +etwor Fayer

– responsi8le )or *aing ro!ting (ecisions

• Data Fin Fayer

– (eals with *essage (elineation, error control an(networ *e(i!* access control

• 3hysical Fayer

– (e)ines how in(i%i(!al 8its are )or*atte( to 8etrans*itte( thro!gh the networ




"nternet;s <9(ayer odel

• Application Fayer

– !se( 8y application progra*

• "ransport Fayer

– responsi8le )or esta8lishing en(-to-en( connections,translates (o*ain na*es into n!*eric a((resses an(seg*ents *essages

• +etwor Fayer - same as in $*I model• Data Fin Fayer - same as in $*I model

• 3hysical Fayer - same as in $*I model

“Please Do Not Touch Alligators”3hysical DataFin +etwor "ransport Application




Com#arison o Network odels



Copyright 2011John Wiley & Sons, Inc. 1 - 2=

essage 'ransmission *sing (ayers



Copyright 2011John Wiley & Sons, Inc. 1 - 2:

)rotocols

• $se( 8y networ *o(el layers

• Sets o) stan(ar(i6e( r!les to (e)ine how

to co**!nicate at each layer an( how to

inter)ace with a(Hacent layers

recei%er sen(er

Fayer +

Fayer +-1

Fayer +1

Fayer +

Fayer +-1

Fayer +1




essage 'ransmission E7am#le




)oints a5out Network (ayer =iew

• Fayers allow si*plicity o) networing in so*eways

– @asy to (e%elop new so)tware that )its each layer

– 5elati%ely si*ple to change the so)tware at any le%el

• atching layers co**!nicate 8etween (i))erent

co*p!ters an( co*p!ter plat)or*s – Acco*plishe( 8y stan(ar(s that we all agree on

– e.g., 3hysical layer at the sen(ing co*p!ter *!st *atch!p with the sa*e layer in the recei%ing co*p!ter

• So*ewhat ine))icient

– In%ol%es *any so)tware pacages an( pacets

– 3acet o%erhea( >slower trans*ission, processing ti*e?

– Interopera8ility achie%e( at the e#pense o) per)ectlystrea*line( co**!nication




1%/ Network tandards

• I*portance – 3ro%i(e a )i#e(/ way )or har(ware an(or so)tware

syste*s >(i))erent co*panies? to co**!nicate

– <elp pro*ote co*petition an( (ecrease the price

• "ypes o) Stan(ar(s – or*al stan(ar(s

• De%elope( 8y an in(!stry or go%ern*ent stan(ar(s-

*aing 8o(y

– De-)acto stan(ar(s• @*erge in the *aretplace an( wi(ely !se(

• Fac o))icial 8acing 8y a stan(ar(s-*aing 8o(y




tandardization )rocesses

• Speci)ication – De%eloping the no*enclat!re an( i(enti)ying

the pro8le*s to 8e a((resse(

• I(enti)ication o) choices – I(enti)ying sol!tions to the pro8le*s an(

choose the opti*!*/ sol!tion

• Acceptance

– De)ining the sol!tion, getting it recogni6e( 8y

in(!stry so that a !ni)or* sol!tion is accepte(




a>or tandards Bodies

• IS >International rgani6ation )orStan(ar(i6ation?

– "echnical reco**en(ations )or (ata co**!nication

inter)aces

–Co*pose( o) each co!ntrys national stan(ar(s orgs.

– Base( in 7ene%a, Swit6erlan( >www.iso.ch?

• I"$-" >International "eleco**!nications $nion '

"eleco* 7ro!p

– "echnical reco**en(ations a8o!t telephone, telegraphan( (ata co**!nications inter)aces

– Co*pose( o) representati%es )ro* each co!ntry in $+

– Base( in 7ene%a, Swit6erlan( >www.it!.int?




a>or tandards Bodies 4Cont%6

• A+SI >A*erican +ational Stan(ar(s Instit!te? – Coor(inating organi6ation )or $S >not a stan(ar(s- *aing

8o(y?

– www.ansi.org

• I@@@ >Instit!te o) @lectrical an( @lectronic@ngineers?

– 3ro)essional society also (e%elops *ostly FA+ stan(ar(s

– stan(ar(s.ieee.org

• I@" >Internet @ngineering "as orce?

– De%elops Internet stan(ar(s

– +o o))icial *e*8ership >anyone welco*e?

– www.iet).org




ome Data Comm% tandards

Fayer Co**on Stan(ar(s

. Application layer

HTTP, HTML (Web)

MPEG, H.323 (audio/video)

IMAP, POP (e-mail)

. "ransport layer

TCP (I!e"e!)

#P$ (%ovell LA%&)

. +etwor layer IP (I!e"e!)

IP$ (%ovell LA%&)

2. Data lin layer

E!'e"e! (LA%)

"ame ela* (WA%)T+ (MA% ad WA%)

1. 3hysical layer

#-232 able (LA%)

Ca!eo"* !i&!ed 0ai" (LA%)

1.2 ( 4b0& modem)




1%< Future 'rends

• 3er%asi%e +etworing• Integration o) oice, i(eo an( Data

• +ew In)or*ation Ser%ices



Copyright 2011John Wiley & Sons, Inc. 1 - =

)er+asi+e Networking

• eans +etwors will 8e e%erywhere/• @#ponential growth o) +etwor !se

• any new types o) (e%ices will ha%e

networ capa8ility• @#ponential growth o) (ata rates )or all

in(s o) networing

• Broa(8an( co**!nications – $se circ!its with 1 8ps or higher >e.g., DSF?



,elati+e Ca#acities o 'ele#hone! (AN!

BN! WAN! and "nternet Circuits%




"ntegration o =oice! =ideo & Data

• Also calle( Con%ergence/ – +etwors that were pre%io!sly trans*itte(

!sing separate networs will *erge into asingle, high spee(, *!lti*e(ia networ in the

near )!t!re• irst step largely co*plete

– Integration o) %oice an( (ata

• +e#t step

– i(eo *erging with %oice an( (ata

– Will tae longer partly (!e to the high (atarates re;!ire( )or %i(eo




New "normation er+ices

• Worl( Wi(e We8 8ase( – any new types o) in)or*ation ser%ices 8eco*ing

a%aila8le

• Ser%ices that help ens!re ;!ality o) in)or*ation

recei%e( o%er www

• Application Ser%ice 3ro%i(ers >AS3s?

– De%elop speci)ic syste*s )or co*panies s!ch as

pro%i(ing an( operating a payroll syste* )or a co*pany

that (oes not ha%e one o) its own

• In)or*ation $tilities >!t!re o) AS3s?

– 3ro%i(ing a wi(e range o) in)o ser%ices >e*ail, we8,

payroll, etc.? >si*ilar to electric or water !tilities?




1%0 "m#lications or anagement

• @*8race change an( acti%ely see to !se newaspects o) networs towar( i*pro%ing yo!rorgani6ation

– In)or*ation *o%e( ;!icly an( easily anywhere an(anyti*e

– In)or*ation accesse( 8y c!sto*ers an( co*petitorsglo8ally

• $se a set o) in(!stry stan(ar( technologies

– Can easily *i# an( *atch e;!ip*ent )ro* (i))erent

%en(ors – @asier to *igrate )ro* ol(er technologies to newer

technologies

– S*aller cost 8y !sing a )ew well nown stan(ar(s



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CH01 Introduction to Data Communications

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