Transcript
Page 1: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Internet Service Providers (ISP)HOW INTERNET SERVICE PROVIDERS WORK

Page 2: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

What is the role of an (ISP)?

Internet Service Providers (ISP)

'An Internet Service Provider (ISP) is a company that provides a user with access to the Internet, usually for a fee.'

Page 3: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Networks

Internet Service Providers (ISP)

‘Home’

Local Area Network (LAN)

‘Business Network’

There are small, medium and larger computer networks all needing access to the Internet.

Page 4: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

The Internet

Internet Service Providers (ISP)

‘Home Computer’

Packets of data are transmitted over the Internet using switched technology guided by the IP address of end computer.

The Internet

‘Another Computer’

21.34.129.86 28.203.156.94

Packet of data’

Page 5: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Transmitting Data packets

Internet Service Providers (ISP)

‘Home Computer’

Here is a more detailed arrangement of how data packets are transmitted across a network.

Modem

Public Telephone Network

RouterModem Pool ISP Port

Server

Router

ISP B

ack

bone

RouterRouter CSU / DSU CSU / DSU‘Another Computer’

LAN

21.34.129.86

28.203.156.94

Page 6: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Internet Service Provider (ISP)

Internet Service Providers (ISP)

‘Business Network’

Small and large networks connect to an ISP via a point of presence (POP).

‘Home’

‘Home Network’

POP• Conventional Phone• Digital subscriber

line• Cable Modem

Point of Presence (POP)

Internet Service

Provider (ISP)

Page 7: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Network Access Point (NAP)

Internet Service Providers (ISP)

‘Business Network’

The ISP then connects to a Network Access Point via a T3 line (night data speed through put)

POP• Conventional Phone• Digital subscriber

line• Cable Modem

Point of Presence (POP)

Internet Service

Provider (ISP)

‘Home’

NAP

Internet Service

Provider (ISP)

T1 Line

T3 Line

Page 8: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Internet Backbone

Internet Service Providers (ISP)

‘Business Network’

The data packets (datagrams) are then sent at high speed across the Internet backbone.

POP• Conventional Phone• Digital subscriber

line• Cable Modem

Point of Presence (POP)

Internet Service

Provider (ISP)

‘Home’

NAP

Internet Service

Provider (ISP)

T1 Line

T3 Line

Internet Backbone

Page 9: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Internet Backbone

Internet Service Providers (ISP)

‘Network Access Points’

This is a simplified diagram of how different networks interface.

Metropolitan Exchange (MAE) privately ownedInternet

Service Providers (ISP)

NAP

NAP

NAP

NAP

RegionalISP

RegionalISP

RegionalISP

RegionalISP

MAE

LocalISP

LocalISP

LocalISP

LocalISP

LocalISP

LocalISP

‘Regional ISP’

‘Local ISP’Internet Backbone

Page 10: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Internet Backbone

Internet Service Providers (ISP)

‘Network Access Points’

A backbone is typically a fibre optic trunk line (OC carrier) that can carry data at high speed.

There are many companies that operate their own high capacity trunk lines (NSP), such as:

- IBM- UUNet- CerfNet- BBN- SprintNet- PSINet

Metropolitan Exchange (MAE) privately ownedInternet

Service Providers (ISP)

NAP

NAP

NAP

NAP

MAE

Internet Backbone

Page 11: Internet Service Providers (ISP) HOW INTERNET SERVICE PROVIDERS WORK

Following Data Packets

Internet Service Providers (ISP)

You can follow a datagram through all the different paths taken to end up at the destination IP address.

In the windows command prompt tyle in, tracert www.bbc.co.uk

(or you can perform the following request online:

http://traceroute-online.com/


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