2012年5月28日星期一

Internet Infrastructure

Today we are learning about Internet Infrastructure.


Hierarchy Of Networks
-from a single computer to LAN.
-from LAN to ISP.
-from ISP to www.


There are a few things that needed in order to connect to internet. The things are:
-computer
-web browser
-Internet access


However,policy and procedure to bring to internet is complicated.


Internet Protocol
-is the internet standard protocol that provides a common layer over dissimilar network.
-to more packet among 'host', computer through gateways.
-every computer assign unique IP address.
IP address consist of 32 bits, also equal to 4 octets of number from 0-225, represent in decimal form instead if binary.
-IP address consist of 2 part:

  1. Identifying network.
  2. Identifying the node/host.
-class of address determined which part belongs to network and             which part belongs to node.
-all node on a given network share the same network pretix but must have a unique host number.

DOMAIN NAME SYSTEM (DNS)
-internet service that translate domains name like www.yahoo.com into numerical IP address like 204.62.131.129.

INTERNET SERVICE PROVIDER(ISP)
- an organization that provides access to the Internet. 
-  can be either community-owned and non-profit, or privately owned and for-profit.

               


Hypertext Transfer Protocol Secure 
(HTTP)
-combination of the Hypertext Transfer Protocol (HTTP) with 

the SSL/TLS protocol.

-It provides encrypted communication to prevent 

 eavesdropping and to securely identify the web server with     
 which you are actually communicating 

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-it can protect against eavesdropping and tampering with the contents of the site or with the information you send to the site.

-makes it possible to know whether you are talking to the right server and protects from passive and active network attacks