Sunday, 3 June 2012

Internet Infrastructure -- Last Lecture

Wednesday, 30th May 2012
This was the last lecture for SPPM 1013. We had learned about Internet Infrastructure as our last topic of this subject.
Firstly, I learned that there is a hierarchy of Networks : -
(I.)          from a single computer to LAN
(II.)         from LAN to ISP
(III.)       ISP to WWW
Besides, other things I came across several specific terms which related to Internet. These terms were Internet Protocol (IP), Domain Name System (DNS), Internet Service Provider (SP) and Hyper Text Transfer Protocol (HTTP).
These things are really technical stuff but I always have a curios heart to know more about them.

Internet Protocol  (IP)
IP is the Internet Standard that provides a common layer over dissimilar networks which is used to move packets among host computers and through gateways if necessary.
IP addresses are used to identify computers available through the Internet. They are numeric and commonly used by computers to refer to other computers. An IP address consists of 32 bits, which distribute evenly in 4 octets (each octet consists of 8 bits). The numbers in each octet are ranged from 0-225. There are two forms of IP address : -
(I)            Numeric form – eg.
(II)          Binary form – eg. 10101000.11010100.11100010.11001100
 There are two parts in an IP address. The beginning of the IP address indicates the networks that it belongs to whereas the other numbers show the host on that network. All nodes in the same network will begin with the same prefix, the rest of the numbers are representing the specific nodes or hosts. There are 5 classes of networks exist nowadays.
Next, we had learned about Domain Name System (DNS)
DNS reflects the name of the individual or organization associated with that Web site and the different parts of a domain name are separated by a period.
DNS is easier to remember as the identity of a specific website when it is compared to the IP address (no matter numeric or binary address).
Lastly, there were two terms that we were required to find out.
Ø  ISP – Internet Service Provider (ISP) / Internet Access Provider (IAP) is business or other organizations that provide Internet access to others, typically for a fee.
Ø  HTTP – Hyper Text Transfer Protocol (HTTP) is the underlying protocol used by the World Wide Web (WWW). It defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. For instance, when we type URL in the searching bar and clicks ENTER, a HTTP command is then sent to the Web Server in order to reach to the requested web page. HTTP only transfers the contents of web page into browser for viewing.

That’s all from me ^^