isdn & bisdn important

8/9/2019 Isdn & Bisdn Important

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Seminar On

ISDN

&

B-ISDN


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Need For Change In Pre-existing Networks:

Lack ofBandwidth, Flexibility and Quality of Analog Voice

Transmission Equipments.

The Public Telephone network Could not effectively

support Non-Voice Services.

Private networks were unable to offeraccess to other

Networks and Users.

Inadequate Support for linking geographically distinct

Networks.

Pre-ISDN Scenario


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ISDN OverviewThere are many types of WAN technologies that can be used to solve the

problems of users who need network access from remote locations.

In this chapter, you will learn about the

services, standards, components, operation, and configuration of

Integrated Services Digital Network (ISDN) communication.

ISDN has been specifically designed to solve the low bandwidth

problems that small offices or dial-in users have with traditional

telephone dial-in services.

Telephone companies developed ISDN with the intention of creating a

totally digital network whilst making use of the existing telephone

wiring system.

ISDN works very much like a telephone - When you make a data call with

ISDN, the WAN link is brought up for the duration of the call and is

taken down when the call is completed


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ISDN allows digital signals to be transmitted over existing

telephone wiring.

This became possible when the telephone company switches

were upgraded to handle digital signals.

ISDN is generally viewed as an alternative to leased lines,

which can be used for telecommuting and networking smalland remote offices into LANs.

What is ISDN?


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ISDN's ability to bring digital connectivity to local sites has many benefits,

including the following:

ISDN can carry a variety ofuser traffic signals including:

digital video, packet-switched data, and telephone network services.

ISDN offers much faster call setup than modem connections

because it uses out-of-band (D, or delta, channel) signaling. For example, some ISDN calls can be setup in less than one second.

ISDN provides a faster data transferrate than modems by using the

bearer channel (B channel of 64kbps).

With multiple B channels, ISDN offers users more bandwidth on WANs

than some leased lines. For example, if you were to use two B channels, the bandwidth capability

is 128Kbps because each B channel handles 64Kbps.

ISDN can provide a clear data path over which to negotiate PPP links.

What Can ISDN Do?


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There are two ISDN services:

BRI (Basic Rate Interface)

PRI (Primary Rate Interface).

The ISDN BRI service offers two 8-bit B channels and one 2-bit D

channel.

ISDN BRI delivers a total bandwidth of a 144-kbps line into threeseparate channels.

BRI B channel service operates at 64 kbps and is meant to carry userdata and voice traffic.

The third channel, the D channel, is a 16 kbps signalling channel usedto carry instructions that tell the telephone network how to handle eachof the B channels.

ISBN Services


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Protocols

Protocols ThatBegin With This

Letter

Are Used For These Purposes

E These protocols recommend telephone standards for ISDN. Forexample, the E.164 protocol describes international addressing for ISDN.

I These protocols deal with concepts, terminology and generalmethods. The I.100 series include general ISDN concepts and the structure of

other I series recommendations; the I.200 series deal with service aspects of

ISDN; the I.300 series describes network aspects; the I.400 series describes

how the UNI is provided.

Q These protocols cover how switching and signaling should operate. The term

signalling in this context means call set-up.


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B-ISDN: Broadband Integrated Services Digital Network

Designed to provide similar services as ISDN

B-ISDN is substantially more capable than ISDN

B-ISDN techonolgy.

Asynchronous Transfer mode (ATM) Switching.

Synchronous Optical Network (SONET) for transport

Integrated network forData , Voice and Video.

Broadband ISDN Overview


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ISDN uses existing telephone network (copper pairs);

B-ISDN uses Optical Fibre.

ISDN is primarily Circuit Switching;

B-ISDN uses only Packet Switching specially ATM CELL

switching.

ISDN uses Pre-defined channel rates;

B-ISDN uses Virtual Channels without prescribed ratesas BandWidth on demand

B-ISDN versus ISDN


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Intro To ATM

ATM standard (defined by CCITT) is widely acceptedby common carriers as mode of operation for

communication particularly BISDN.

ATM is a form of cell switching using small fixed-sized

packets.

Basic ATM Cell Format

Header Payload

5 Bytes 48 Bytes


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Asynchronous Transfer Mode(ATM)

MUX

`

Wasted bandwidth

ATM

TDM

4 3 2 1 4 3 2 1 4 3 2 1

4 3 1 3 2 2 1


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Genesis Of ATM

Traffic Integration Voice, video and data traffic

Multimediabecame the buzz word

One-way batch Web traffic

Two-way batch voice messages One-way interactive Mbone broadcasts

Two-way interactive video conferencing

Quality of Service guarantees (e.g. limited jitter, non-blocking streams)

LAN Interoperability

Mobile and Wireless nodes


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Introduction to Optical Fibers

Fibers of glassUsually 120micrometers in

diameterUsed to carry signalsin the form of lightover distances up to

50 km.

No repeatersneeded.


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Introduction (Cont)

Core thin glass centerof the fiber where lighttravels.

Cladding outeroptical materialsurrounding the core

Buffer Coating plastic coating thatprotects the fiber.


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Advantages of Optical Fibre

Thinner

Less Expensive

Higher Carrying CapacityLess Signal Degradation& Digital Signals

Light Signals

Non-FlammableLight Weight


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Areas of Application

Telecommunications

Local Area Networks

Cable TV

CCTV

Optical Fiber Sensors


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How Does Optical Fibre Transmit

Light??

Total Internal Reflection.

Fibre Optics Relay Systems has

-Transmitter

-Optical Fibre

-Optical Regenerator

-Optical Receiver


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Total Internal Reflection in Fiber


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Submitted By:

Tarun Garg

7040301192

Thank You


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References

Wikipedia.org

Google.co.in

ATM networks By Sumit Kasera

ATM networks By RainerHandel, Manfred

N Huber& Stefan Schroder

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