Just Mine: Day 8 - Wednesday, 30 May 2012

Hi everyone. Today is the last class for this subject. The topic for today's lesson is Internet Infrastructure.

The Internet:

Computer Network Hierarchy

1. From a single computer to LAN

2. From LAN to ISP

3. From ISP to WWW

Internet Service Provider (ISP)

A regional or national access provider.

A regional ISP usually provides Internet access to a specific geographic area.

A national ISP is a business that provides Internet access in cities and towns nation wide.

In order to connect with Internet, you need to have:

1. computer

2. web browser

3. internet access

How Data and Information Travel the Internet

Computers connected to the Internet work together to transfer data and information around the world using servers and clients and various wired and wireless transmission media.

On the Internet, computer is a client that can access data, information, and services on a variety of servers. The inner structure of the Internet works much like a transportation system. Several main transmission media carry the heaviest amount of traffic on the Internet. These major carriers of network traffic are known collectively as the Internet Backbone.

Internet Addresses

The Internet relies on an addressing system to send data and information to a computer at a specific destination.

An IP address, short for Internet Protocol address, is a number that uniquely identifies each computer or device connected to the Internet.

The IP address usually consists of four groups of numbers, each separated by a period. The number in each group is between 0 and 255.

For example, 72.14.207.99 are an IP address. In general, the first portion of each IP address identifies the network and the last portion identifies the specific computer.

These all-numeric IP addresses are difficult to remember and use. Thus, the Internet supports the use of a text name that represents one or more IP addresses. A domain name is the text version of an IP address.

IP address ----> 72.14.207.99

Domain name ----> www.google. com

Domain Name System (DNS)

The method that the Internet uses to store domain names and their corresponding IP addresses. When you specify a domain name, a DNS server translates the domain name to its associated IP address so that data and information can be routed to the correct computer.