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Sub topic : Internal architecture of ISP

.

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Recap

In the previous class, you have learnt about

• ARPA Net (Advanced Research Project Agency Net)

• WWW (World Wide Web)

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OBJECTIVES

On completion of this period, you would be able to know about

• ISP

• Typical ISPs

• Types of ISPs

• ISP connection options

• Internal Architecture of ISP

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ISP is an Internet Service Provider that provides

• Internet access to the Individuals

• Internet access to the Companies

• Services such as web site building and virtual hosting

• It can also be called as a Internet Access Provider.

Internet Service Provider

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Typical ISPs

• WorldNet

• AT & T

• IBM Global Network

• MCI

• Netcom

• UUNet etc

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Depending on the Range ISPs can be

• Local ISPs

• Regional ISPs

• National ISPs

• International ISPs

Types of ISPs

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ISP ISP ISP ISP

Regional ISP Regional ISP

National ISP

X X

X XXX

Fig 1.Structure of a national ISP

…….

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National ISP

National ISPNational ISP

National ISP National ISP

NAP

xx

x

Fig.2.Interconnection of national ISPs

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• Home user connection

• Business connection

ISP Connection Options

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• Dial-up

• DSL

• Broad band wireless access

• Cable Modem

• ISDN

Typical Home user connections

ISP

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• DSL

• SHDSL

• Ethernet Technologies

Typical Business connectionsISP

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Fig.3.Internal Architecture of ISP

Router

Router

Internet

SUBSCRIBERS

Set of modems

Remote access server

SMTP server

Web Server

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• Set of Modems

• Remote Access Server

• SMTP Server

• Web Server

• Routers

ISP Architecture consists of

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• Convert Analog signal on the line to the Digital

• Connect ISP to the Subscriber

Set of Modems

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Remote Access Server

• All subscribers are connected to RAS through set of

modems

• Maintains database of valid user id and password

• It also verifies user id and password

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• It is Simple Message Transfer Protocol

• It stores subscribers e-mails until the subscriber connects

to the internet

• It sends and receives mails on behalf of its subscriber

SMTP Server

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• Subscribers can create their own web pages

To provide value added services such as

• News update

• Weather information

• Technical updates

• Sports updates

• Chat facilities

Web Server

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• It maintains routing tables

• Subscribers may be connected to the Internet

through Routers

Routers

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In this class, you have learnt about

• ISP (Internet Service Provider)

• ISP types

• Its Internal Architecture in detail

Summary

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(1) The function of RAS is

(a) To Authenticate the subscriber

(b) To maintains database of valid users

(c) a&b both

Quiz

21

(1) Define ISP

(2) Explain the Internal Architecture of ISP

Frequently Asked Questions