Blog / OSI Model
OSI Stand For
Open System Interconnection, it is a standard to communication two computer accross the network. It defines some standard layer from how bit will be transfer to the application.
The Problem OSI Model Solve
Suppose we want to transfer data between two computer across the internet, the installted hardware and software may be different in this two computer. So encoding and decoding of bits from receiving to showing it to user can be different. This can cause huge problem. To resolve the problem OSI Model is born.
Layers of OSI Model
In OSI model every layer is some package of protocol.
Layer 1: Physical Layer:
Received Sinal and Convert it to frame for the Data Link Layer.
Layer 2: Data Link Layer:
Data link layer embaded in computer network interface card. It perform two basic operation it access media using framing
Physical Address : mac address assigned.
CSMA: Career Sense Multiple Access.
Layer 3: Network Layer:
Send DAta from one computer and other computer. Ip addressing is done here. It’s assign sender and receiver an ip address. Routing is done here.
Layer 4: Transport Layer:
It controls relaibility of data transform. port, secuence,
Automatic Repeat Request
TCP Does give Feedback While UDP does not give any feedback.
Layer 5: Session Layer:
It helps setting up and keep the connection with network. It keep track which data packet belong to which file in a perticular connection. it help with Sessing management, authentication, and in authorization.
Layer 6: Presentation Layer:
It received data from application layer. It’s convert appliation data into binary format. In here computer uses data compression such as gzip. Before that data is encrypted. Translation / Compression / Encryption / Decription
Layer 7: Application Layer:
Is used by network application, means computer application which use Network. Expample: google chrome. There are many protocol involve here, such as http, https, ftp, smtp, telnet etc..
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