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. 168.212.226.204
(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 ^^