internet infrastructure

the internet is a global network connecting millions of computers using a common set of communications protocol called IP (internet protocol)

INTERNET PROTOCOL

it is the imternet standard protocol that provides a common layer over dissimilar naetworks, used to move packets among host computers and through gateways if necessary.

• used to move packets among host computer

• consist of 32 bits

• 4 octets of no. from 0-255

• represented in decimal form instead of binary form

• easy to remember the decimal no. rather than binary form

• consist of two parts ; identify network and identify nodes

• eg : 168.223.210.221

 class A network

• binary address start with 0

• the decimal no can be anywhere from 1 to 126

• the first 8 bits identify the network

• the others bit indicate the host within the network

• exp : 102 . 168 . 212 . 226 ( first 8 bits is 102)

class B network

• binary addresses start with 10

• the decimal no can ne anywhere from 128 to 191

• the no 127 is reversed for loopback and is used for internal testing on the local mechine.

• exp : 168 . 212 . 226 . 204( 168.212 is to identifies the network) 

class C network

• binary addresses start with 110

• the decimal no can be anywhere from 192 to 223

• the first 24 bits identify the network.

• exp : 200 . 168 . 212 . 226 ( 200.168.212 is first 24 bits)

class D network

• binary addresses start with 1110

• decimal no can be anywhere from 224 to 239

• it are used to support multicasting.

class E network

• binary no start with 1111

• decimal no can be anywhere from 240 to 255

• it are used for experimentation

• they neve been documated or utilized in a standard way. 

domain name system, DNS

• is an internet service

• translates domain names like www.hotwired.com into numerical IP addresses like 204.62.131.129.

• it is the naming scheme which consist of a hierarchical sequence of names

internet service provider, ISP

• also called ISPs

• it is a company that provides access to the internet

• equipped with a modem

• ISPs themselves are connected to one another through NETWORK ACCESS POINTS

HTTP

• hyper text transfer protocol

• defines how messages are formatted and transmitted, and what actions web servers and browser should take in response to various command.