Past
Using the Internet in the Early days (1990's):
- Dial up - http://youtu.be/UsVfElI-7oo
- 128 kbit (Thousands of bits per second)
- We used to pay per minute of connection and would download mail -
disconnect, then reconnect to send mail again.
- Mostly e-mail and text based websites - Netscape, later Internet Explorer
Now we have Broadband ( megabit - millions of bits a second)
via wires or wireless and use of digital mobile telephone systems.. and
even Gigabit (thousands of millions bits a second) - This means much
more information, and more types of information can be moved around quickly.
How did it begin?
The Internet began as a Cold War project to create a communications
network that was immune to a nuclear attack.
In the 1969, the U.S. government created ARPANET, connecting four
western universities and allowing researchers to use the mainframes of
any of the networked institutions.
New connections were soon added to the network, bringing the number of
"nodes" up to 23 in 1971, 111 in 1977, and up to almost 4 million in 1994.
As the size of the network grew so did its capabilities: In its first 25
years, the Internet added features such as file transfer, email, Usenet
news, and eventually HTML.
The Internet is basically a global system of interconnected computer
networks.
http://en.wikipedia.org/wiki/History_of_the_Internet
Here's what it "looks" like today:
http://en.wikipedia.org/wiki/File:Internet_map_4096.png
When was its Birthday ?? Actually, like most inventions it has
evolved gradually….
http://www.geeksaresexy.net/2009/09/02/birth-of-the-internet/
Present
Key Features of the modern Internet:
Common Protocol: (rules of communication) on all machines.
Different computers and devices made by different manufacturers could
"talk" to each other. - TCP/IP
Dynamic routing of Information: Chop up the information into
chunks (packets) If the route is closed one way, send the packet via
another route ! - Bomb proof.
See this simple animation :
http://www.pbs.org/opb/nerds2.0.1/geek_glossary/packet_switching_flash.html
IP addresses Internet computer nodes and routers on the Internet
are identified by unique IP addresses:
IPV4 = four numbers, each from 0 to 255. e.g. 178.24.113.21
Total of 4,294,967,296 addresses. But large blocks of addresses are
reserved for special uses and are unavailable for public allocation.
Despite tricks to enable one number to serve several nodes, (Network
Address Translation) we are running out of numbers! Hence IPV6 which has
eight hexadecimal numbers (each number up to 65535) = and more than
7.9×(ten to the 28) times as many IP numbers as IPv4.
(more than there are grains of sand on all the beaches of the world)
The two systems are completely different and we are still mostly using
IPV4 in 2013, though IPV6 was launched in 2012.
Test your IPV6 connectivity: http://test-ipv6.com/
DNS - Domain Name Service Translates addresses of web sites (words)
into their IP addresses (numbers). A DNS Server - is a computer on the
Internet which processes part of this service - the system has to query
three types of name-server in turn, the answer to each query refining
the search.
See video : http://youtu.be/72snZctFFtA
How Many DNS Servers ?:
http://www.howmanyarethere.org/how-many-dns-servers-are-there-in-the-world/
Videos:
There and Back -A Packet's Tale - How does the Internet work?:
http://youtu.be/WwyJGzZmBe8 (3 minutes)
The Good Warriors of the Net - a rather corny animation by Ericsson
http://youtu.be/x9XWxD6cJuY
Additional Services:
On top of this - There are additional protocols for different services
which use the Internet e.g.
- HTTP : Hyper Text Transfer Protocol (World Wide Web browsing)
Developed by Brit, Tim Berners Lee
- FTP: - File transfer Protocol - uploading and downloading files.
- Telnet protocol - connect directly to another computer and control
it at a distance
- Email protocols - for e-mail which is downloaded to your computer
by programmes like Outlook - IMAP, POP, SMTP
- Peer to Peer (P2P) - File sharing (Torrents)
New protocols for new services:
- VOIP - Voice over Internet Protocols - Telephone using the internet.
- IP Multicast protocol - Video streaming.
Number of Internet Users today:
http://www.internetworldstats.com/stats.htm
More Stats!
http://royal.pingdom.com/2013/01/16/internet-2012-in-numbers/
Despite social networking etc..E-mail is still tops !
- Internet connection now not just via cable and WiFi, 3G telephone
system has become more and more important.
- Laptops with 3G (161million in 2012)
- Tablets with 3G (35m)
- Mobile video already makes up more than half of the data
transmitted worldwide
