28/5/12
INTERNET INFRASTRUCTURE
Hierarchy
of networks :
- - From single computer to LAN
- - From LAN to ISP
- - From ISP to WWW
In order to
connect yourself to the Internet,
-
Computer
- Web
browser
-
Internet
access (ISP)
However,
policy and procedure to bring you to internet is quite complicated.
Internet
Protocol (IP)
- To
move packets among ‘Host’ computer through gateways.
- Every
computer assign unique IP address.
- IP
address consist of 32 bits (shown as 4 octets of numbers from 0-225 represented
in decimal form instead of binary).
IP address consists of 2 part :
o
Identifying the network
o
Identifying the node/host
Class
of address determines which part belongs to the network address and which part
belongs to node.
o
E.g. : Fakulti Pendidikan UTM uses 168
as Identity for network.
All
nodes on given network share the same network (share network identifier) prefix
but must have a unique host number.
-Binary
address start with 0, therefore decimal number can be anywhere from 1 to 126.
-The
first 8 bits (the first octet) identify the network and the remaining 24 bits
indicate the host within the network.
-102.168.212.226
Class B network (0>X = Class B)
-Binary
address start with 10 = decimal number can be anywhere from 128 to 191.
-The
number 127 is reserved for loopback and is uses for internal testing on local
machine.
-The
first 16 bits = identify the network and the remaining 16 bits indicate the
host.
-168.21.226.104
Class C network
-Binary
address start with 110 = decimal number can be anywhere from 192 to 223.
-The
first 24 bits = identify the network
-200.168.212.226
Class D network
-Binary
address start with 1110 = decimal number can be anywhere from 224 to 239.
-Used
for support multitasking.
Class E network
-Binary
address start with 1111 = decimal number can be anywhere from 240 to 255.
-Used
for experiment, never been documented/ utilized in a standard way.
- 127.0.0.1 is the loopback Internet protocol (IP) address also referred to as the “localhost.”
- The address is used to establish an IP connection to the same machine or computer being used by the end-user.
- The same convention is defined for computer’s that support IPv6 addressing using the connotation of ::1.
- Establishing a connection using the address 127.0.0.1 is the most common practice; however, using any IP address in the range of 127.*.*.* will function in the same or similar manner.
- The loopback construct gives a computer or device capable of networking the capability to validate or establish the IP stack on the machine.
- 127 is an easy number to remember (01111111).
- 127 is the last network number in a class A network with a subnet mask of 250.0.0.0.
- 127.0.0.1. is the first assignable address in the subnet.
DNS (DOMAIN NAME
SYSTEM)
- - Internet
service that translates domain names like www.yahoo.com
into numerical IP address like 204.63.131.129.
- - moe.gov.my → DNS
- - Why
we use DNS?
o
Domain names or alphabetic, because it
is easier to remember.
ISP (INTERNET SERVICE
PROVIDER)
- it refers to a company that provides Internet services, including personal and business access to the Internet.
- The service provider provides a software package, username, password and access phone number.
- Equipped with a modem or broadband.
- In addition to serving individuals, ISPs also serve large companies, providing a direct connection from the company's networks to the Internet. ISPs themselves are connected to one another through Network Access Points (NAPs).
- ISPs may also be called IAPs (Internet Access Providers).
- it refers to a company that provides Internet services, including personal and business access to the Internet.
- The service provider provides a software package, username, password and access phone number.
- Equipped with a modem or broadband.
- In addition to serving individuals, ISPs also serve large companies, providing a direct connection from the company's networks to the Internet. ISPs themselves are connected to one another through Network Access Points (NAPs).
- ISPs may also be called IAPs (Internet Access Providers).
Eg : Celcom, mobile
What is HTTP?
Hyper Text Transfer Protocol
Hyper Text Transfer Protocol
•Client sends request
(HEAD, GET, PUT)
•Server replies with
–response code
(3-digit)
–response text (string)
–document (depending on
code)
•Client displays
document or error to user
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