Download - The OSI Model
What is an OSI?
•OSI stands for Open System Interconnection
•This was developed by the ISO (International Organization for Standardization) in the year 1977.
What is the Main Objective of the OSI
Model?
–To standardize Networking to make sure that everyone was connected through a common network standard.
7 Layers
Layer Function7 Application
6 Presentation
5 Session
4 Transport
3 Network
2 Data link
1 Physical
To Remember the 7 Layer
Layer Function
Note
7 Application All
6 Presentation People
5 Session Seem
4 Transport To
3 Network Need
2 Data link Data
1 Physical Processing
PHYSICAL
•This is the Layer that physically connect the networks together.
•Hardware•Medium of Signals
–Such as Cables, satellite, etc.
Some Physical Layer Devices
Split the data into packets This layer makes possible divide a way to exchange data
or a common local media
DATA LINK
Send packets to address Supplies the means to
exchange pieces of data over the network between identified and devices.
NETWORK
Ensures that packets arrive, and error free and are in correct order
TRANSPORT
Established and coordinates connection between computers
This layer establishes, manages, and terminates connection also known as session between 2 network address
SESSION
Allows transfer of files between different formats. Encryption is one of the services in this layer.
Encryption is the translation of data into a secret code. Encryption is the most effective way for data security. To read an encrypted file you must have a password or a secret key.
PRESENTATION
This is the layer where people do their work , such as sending e-mail or requesting to transfer a file across the network
E-mail, files requests, file transfers, etc.
APPLICATION