internet infrastructure

• internet is a global network connecting millions of computer using a common set of communication protocols called TCP/IP.
• a hierarchy of networks:
• single c0mputer => LAN => ISP => WWW
• to connect with the internet, we need:
• computer
• web browser
• internet access

INTERNET PROTOCOL (IP)

• provides a common layer over dissimilar networks
• used to move packets among 'host' computers and through gateways
• IP add consist of 32 bit ( 4 octets of number from 0-255 represented in decimal form instead of binary form).
• IP add ==> 168.212.226.204
• binary form ==> 10101000.11010100.11100010.11001100
• IP add consist of 2 part:
• identifying the network
• identifying the node/host

CLASS A NETWORK

• binary add start with 0
• decimal number can be anywhere from 1 t0 126
• the 1st 8 bits (1st 0ctet) identify the network and the remaining 24 bits indicate the host within the network.
• example:  102.168.212.226
•  102 ==> identify the network
• .168.212.226 ==> identify the host

CLASS B NETWORK

• binary add start with 10
• decimal number can be anywhere from 128 to 191
• the 1st 10 bits (1st 2 octet) identify the network and the remaining 16 bit indicate the host within the network
• example: 168.212.226.204
• 168.212 ==> identify the network
• 226.204 ==> identify the host

* 127 is reserved for loopback and is used for internal testing  on the local machine

CLASS C NETWORK

• binary start with 110
• decimal number can be anywhere from 192 to 223
• the 1st 24 bits (1st 3 octet) identify the network and the remaining 8 bits indicate the host within the network.
• example: 200.168.212.226
• 200.168.212 ==> identify the network
• 226 ==> identify the host

CLASS D NETWORK

• binary add start with 1110
• decimal number can be anywhere from 224 to 239
• used to support multicasting

CLASS E NETWORK

• binary add start with 1111
• decimal number can be anywhere from 240 to 255
• used for experimentation.
• never have been documented or utilized in a standard way

DOMAIN NAME SYSTEM (DNS)

• internet service that translate domain names like www.hotwired.com into numerical IP add (204.62.131.129) which computer on the net use to communicate with each other.
• Internet naming scheme which consist of a hierarchical sequence of names
• from the most specific to the most general (left to rigth),
• separate by dots (emoe.gov.my)
• domain name are alphabetic (easeir to rememner)

INTERNET SERVICE PROVIDER (ISP)

• can be either community-owned and non-profit, or privately owned and for-profit.
• also called IAPs ( Internet Access Providers)
• company that provides access to the internet.
• for a monthly fee, the service provider gives you a software package, username, password, and access phone number.
• equipped with a modem, you can then log on to the internet and browse the www or send and receive e-mail
• ISPs are connected to one another through Network Access Points (NAPs)

HTTP

• short for HyperText Transfer Protocol
• defines how message are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands.
• transfer the content of a web page into a browser for viewing.