THE SEVEN LAYERS OF OSI

The Seven Layers of OSI Model

It is a model to standardize networking.  OSI means Open System Interconnection.  Allow different companies (nodes) to talk to different other companies.  They usually brought in the range of communication for others.

This OSI model is helping different devices to communicate with each-other.  It gives signal to devices when and how to send data or not to send data.

The bottom layers, physical layer and data link layer, transmit data.  Middle layers, network layer, transport layer and session layer, usually communicate with different computers and other devices.  Top layers,  presentation layer and application layer, usually software applications until these present data to us.

INSTALLATION OF A SOFTWARE/PROGRAM

INSTALLING A SOFTWARE:


When installing a software it is recommended to check if it is from a reliable source. Usually the steps of installing a software are considered very simple.  Base idea to install a software is below:


1. Run the setup file
2. Read the agreement instructions and if everything is okay then click on the check box stating normally I agree and click next
3. Indicate the location where you want the software to be installed by clicking on browse and going to the drive location if not as default location like program files.
4. Click next, next and let the software to be installed.
5. Software may ask to see the reading file or auto run after end of installation (depends on users and their preference)
6. When the dialogue box comes as FINISH written on it then click finish and enjoy using the software


Recommendation: Always install software with anti-virus already installed in your computer.

NETWORK TERMINOLOGY

WORK STATION:
Work Station can be as common as personal computer at home (a regular computer).




HOST:
Host in networking means provider of information to its client within a network.  Host gives data.



CLIENT:
Client in networking language means the computer that receives data from host.  Client receives data.




SERVER:
Server allows lot of different users information already stored in it.  For example:  Web page......many work station can be connected to a web page and receive data from there.



NIC (Network Interface Card):
Network Interface Card allows to connect with wire or without wire (wireless) to internet, to a network.  This card needs to be installed in the computer.


PROTOCOL:
Protocol is how data is formatted, transmitted and received. In short, how you send data over a network.


TOPOLOGY:
Topology is the design of a network.  Considering visibility topology can be classified as Physical which can be seen and Logical as how data is transmitted, which cannot be seen.


There are 5 (five) major types of topology, which are:
    -  bus topology
    -  ring topology
    -  star topology
    -  tree topology
    -  mesh topology

INTRODUCTION TO NETWORKING

COMPUTER NETWORK:
Network of interconnected computers that are all connected to each other. Its target is to share information among one computer to another computer.


NETWORK TYPES:
There are three different types of network.
    - LAN (local area network)
    - MAN (metropolitan area network)
    - WAN (wide area network)
These are classified according to the size of the network and area of coverage.


LAN:
Local area network is commonly used inside of an office or one house area.  Mainly, it does not reach outside a building.


MAN:
Metropolitan area network is estimated a coverage size of less than 30 miles area.  There can be more than one building but usually couple of buildings.

WAN:

Wide area network has ability to cover bigger area.  Area over 30 miles are connected through using this network type.


NODE:
Node terminology is used to mean anything that physically connected to network.


COMMUNICATION MEDIA:
The way how nodes are linked is known as Communication Media. For example: two most common communication media can be cable usually used to connect to broadband or fiber optic cable.