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Assignment no # 3

Integrated Services Digital Networks (ISDN) Introduction

A few years ago, when PCs transferred data so slowly that PCs users

could see pages download line by line, the Baby Bells promised that a

technology called ISDN would be the solution After a decade of

inaccurate initiation and failed e!pectation, ISDN is "nally reachingimpulse

Before high# speed cable modems and digital subscriber lines, ISDN

was the only way to run the Internet $hereas ISDN doesn%t &ualify

technically as a broadband connection, it can transfer data between

the Internet and PC at up to '()*bps##more than double the speed of a

standard +* modem

ISDN lin- two digital channels within a single phone line so it can carry

.oice, data, fa!es, and .ideo simultaneously,

Integrated Services Digital Network (ISDN)

Integrated Ser.ices Digital Networ- /ISDN0 is an e!clusi.ely digital

telephone1 telecommunications networ- for carrying .oice, data,

images, and .ideo at high speed by sending digitally encoded signals

ISDN pro.ides 2end#to#end2 digital ser.ice and can wor- on the copper

wiring phone lines that are in most homes and businesses today

ISDN is a telephone company technology that pro.ides digital ser.ice

typically in increments of 3*bps channels ISDN has been around formany years, but its popularity is now only beginning to increase due to

the limitations of analog modems and the increase of Internet usage

ISDN re&uires the Phone Company to install ser.ices within their phone

switches to support this digitally switched connection ser.ice 4he 5ise

of this ser.ice initially had a slow start and was delayed by high costs,

lac- of standards and low acceptance rate by consumers

Two basics of ISDN Services

' Primary 5ate Interface /P5I06 is the ISDN e&ui.alent of a 4' circuit Itpro.ides (7 B#Channels and a 3 *ilobit#per#second D#channel and

runs at '+33 megabits per second

( Basic 5ate Interface /B5I06 is deli.ering to the o8ce or home It

pro.ides two B#channel and one D#channels o.er one or two pairs of

phone wires at a speed of '33 *bps B#channels are 2bearer2

channels that carry data and ser.ices 4he D#channel usually carries

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the signaling and administrati.e o.erhead used to set up or

terminated calls

Functionalit

All ISDN lines pro.ide three discrete communications circuits

9ach ISDN line actually has three channels: a '- signaling data

channel /D channel0 and two 3*#bearer channels /B channel0 4he D#channel shuttles dialing, caller ID, and ringing information between the

user%s ISDN e&uipment and the local Phone Company and is not

typically used for data 4he ISDN router can use the B#channels for

.oice calls or for data 9ach channel has a separate phone number,

allowing user to place .oice calls on one channel while sending or

recei.ing data o.er the other 4he two bearer channels each pro.ide

3 *bps of dial#up bandwidth Similar to ordinary phone lines, bearer

channels pro.ide a switched connection between one ISDN line and

another phone line

Internal ISDN adapters can ta-e the fullest ad.antage of ISDN line

4hese are cards that go inside a PC Internal adapters re&uire user to

open the PC to install the card In order to install an internal adapter,

user needs a slot free in the PC that supports the same type of bus

/ISA, 9ISA, PCI, for e!ample0 as the card user want to install

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9!ternal ISDN adapters are easy to install and do not re&uire any

special software, but they do not pro.ide the same le.el of

performance that internal adapters do 9;495NA

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>igh#speed electronic "le deli.eries to remote customers

9!amples6

5esearchers

*nowledge $or-ers

Students

Businesses

?o.ernment Agencies

4elecommuters

>igh#speed access to head&uarters% igh#speed access to other telecommuters

9!amples6

Programmers and software de.elopers

9ngineers

?raphic artists

Architects @ultimedia de.elopers

Anyone who wants high#speed access

or periodic transfers of large amounts of data when6

ull#time dedicated connections are not re&uired or cost eecti.e

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Analog dial#up ser.ice is not fast enough to handle the "le sies

re&uired

9!amples6 Nightly uploading of indi.idual branch1store location daily acti.ity

data

Database access and updating

>ost#to#host or terminal#to#host "le transfer

Screen sharing

Collaboration with customers on graphic#intensi.e "les

Ad.ertising 9ngineering Architecture

Des-top publishing

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Eideoconferencing sa.es tra.el time and e!pense while

facilitating face#to#face communications

$ith ISDN, Eideoconferencing has the Fe!ible connecti.ity of a

phone call

9!amples6

5emote meetings Collaborati.e pro=ects with remote wor- teams

4raining

Arraignments

Security sur.eillance

Customer ser.ice

4ra8c monitoring

PC screen sharing and =oint document editing Gsing PC and telephone simultaneously

9stablishes a .oice call on one B channel and a circuit#switched or

pac-et#switched data call on the other B channel

4ransfers large data "les at speeds up to 3 *bps

9!amples6

Hn#line completion of forms, contracts, "nancial documents

5emote co#authoring and editing

acilitation of wor- group collaboration, planning and scheduling

4ight deadline information1data transfer between users or

locations

9!amples6

Small businesses that cannot ris- missing incoming calls

because the line is busy

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Store#front or home#based mail order businesses

5estaurants and other businesses that depend on telephone

reser.ations, appointments and orders

!a$abilit

ISDN can perform multiple applications such as.ideoconferencing, electronic courier ser.ices and small o8ce#home

o8ce needs 4he ser.ices lets users maintain constant *#bps

connections to a corporate

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ISDN %ene&ts

5educed Networ- @anagement and @aintenance Simpli"ed maintenance using the public switched networ- for

.oice, data and pac-et switching

No need to predetermine all possible connection re&uirements

Dial#up access to dierent I9Cs

Communications Cost Sa.ings

Data

5educed retransmissions o.er analog dial#up, sa.ing time

and money

Increased transmission speeds at the same per#minute rates

intra

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Hne line pro.ides two .oice channel capability o.er one

twisted pair

Pac-et switched data on B or D channel

9asy Networ- Connecti.ity and 9!pansion

Data communication as easy as a .oice phone call

Bandwidth#on#demand @a-es international or nationwide communication aordable

9!panded a.ailability to support growing digital data applications

5eliability

B#channel data capability

Circuit Switched Data /CSD0 Networ-

B#Channel Pac-et Data

Designed and engineered for switched digital data ser.ices

9nhanced networ- maintenance and testing capabilities

9nd#to#end digital technology

B#channel .oice capability

@ost reliable .oice ser.ices a.ailable

le!ibility

Simultaneous .oice and data ISDN line

$idely a.ailable dial#up ser.ices for .oice and data

le!ible access to I9C%s .oice and data networ-s

I9C pro.ides inter

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Broadband ISDN capabilities '++ @bps and higher

' ISDN

4here are other technologies that ha.e capabilities similar to ISDNAlternati.es include + -bps modems, cable modems, AsymmetricalDigital Subscriber ere are some of the ad.antages of ISDN6 It pro.ides guaranteed dedicated bandwidth, which is not shared

among many users thus oering security and consistency

It uses the e!isting phone line and can easily be con.erted for ISDNser.ice

It supports dialed digital connections worldwide It pro.ides clean, clear .oice connections and high#&uality data

connections

It simultaneously supports feature rich .oice, data, and .ideo calls

It connects &uic-ly to the Internet unli-e a dial#up modem

ull duple! operation # bandwidth is the same in both directions iea ' @egabyte "le can be sent as &uic-ly from the user to thenetwor- as from the networ- to the user

4here is wide .ariety of user e&uipment a.ailable that wor-s with

ISDNData Transfer ate

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!onclusion

ISDN has been persistently maintaining their capability in the

communication mar-et Because ISDN is an international, open, public

system with guaranteed deli.ery, therefore this technology is an

industry preference 4oday ISDN is a.ailable from practically e.ery

telephone company: howe.er, the installation, monthly and usage

charges .ary by region ISDN is a.ailable to nearly 'KK percent of thepopulation in densely populated states and LK to )K percent of phone

customers in rural states ISDN has three ma=or ad.antages: bandwidth

optimiation, allowing one phone line to act as two, combining the

power of two lines onto one circuit for faster speed, its reliability and

simplicity for computer illiterate users ISDN is standards based both

in the GS and foreign countries

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Because of speed#depri.ed, Internet users will consider ISDN as their

choice instead of waiting for ADS