How the Internet functions

How does the Internet work?

The Internet is a network of interconnected computers around the world. Packets of data are exchanged over this network. The Internet has existed since 1969 when 4 computers or hosts were linked together in the ARPAnet system.

from http://som.csudh.edu/cis/lpress/history/arpamaps/press.jpg

Email was invented by Ray Tomlinson of BBN in 1972.

By 1980, Email and data exchange the primary activity for the 213 hosts from the US government, researchers and universities. Many countries began to link into the network. The first virtual community was the Well in 1985.

In 1991, Tim Berners-Lee released the World Wide Web (WWW) protocol that used hypertext to link documents together. When you click on a link, you are using hypertext to connect to some other information from another web site or from some other part page on a website. The commercial use of the Internet was allowed after the NSF lifted the restriction. By 1992, there were 1 million hosts on the Internet.

Computers stats

2006 was the 25-Year Anniversary of the PC that began in 1981
IBM-Compatible PC Sales have topped 1. 5B Units Worth $B 3,100.

Operating Systems

1. Windows XP                    57 million                                 (83%)
2. Win 2000                           4 million                                   (6%)
3. Mac                                2.9 million                                   (4%)
4. Win 98                              2 million                                    (2%)
5. Unknown                           907 thousand                            (1%)

Other sources claim a higher rate for Mac use. " Market Share report claims that 6.22 per cent of online traffic in January 2007 was on the Mac platform. Specifically, PowerPC Macs had (4.34 per cent) and Intel-powered Macs had (1.88 per cent)."

Top 7 Browsers Used in Feb. 2007

1. MSIE 6.x	39 million	(58%)
2. MSIE 7.x	16 million	(24%)
3. FireFox	7 million	(11%)
4. Safari	2 million	(3%)
5. MSIE 5.x	780 thousand	(1%)
6. Unknown	650 thousand	(1%)
7. Opera x.x	389 thousand	(1%)

Each computer connected to the Internet has a unique IP address that consists of a 32-bit number that is broken up into four parts separated by a dot. Each part has an 8- bit numbers in the range 0 to 255 called octets.
Check your IP address on your computer : http://www.whatismyipaddress.com/

CIDR (Classless Inter-Domain Routing) uses a network prefix to identify a network gateway. The CIDR acts like a area code in a phone number. In the CIDR address 205.128.11.108/23, the "/23" showes the first 23 bits refer to a unique networkand the rest refer to a specific IP host.

How long does it takes for data to go from point A to point B and back. A typical response time on the Internet is 200 ms, which is 200 milliseconds (thousandths of a second) = 1/5th of one second (http://www.internettrafficreport.com/faq.html#response).

Why does the speed of the Internet need to increase? For Video, TV and other large files.

"In the video age, too much is not enough. Akamai's global network now delivers 300 billion bits a second to computers around the world. That is enough to handle the constant barrage of Yahoo e-mails, iTunes downloads and YouTube-style videoclips. But now imagine that someone uses the Net to broadcast a TV show that gets a single Nielsen point (1% of the nation's 110 million TV households). The delivery would need a trillion bits, a terabit, per second. CSI would need 14 terabits. To deliver the same show in high def would require 100 terabits. That's 300 times Akamai's current output." Scott Woolleyin Forbes on 04.23.07