#OSI Layers

 OSI(Open System Interconnection)-

 it is developed by ISO(International Standard of Organisation)which describes the flow of information from one computer to another. 

Physical Layer

it is responsible for bits over the medium . 

Data Link Layer

it is responsible for frames . (MAC, LLC) protocol works on this Layer. 

Network Layer

it is responsible for packets and routing . (TCP/IP) protocol works on this Layer.

Transport Layer

it is responsible for end to end delivery of packets. (UDP) protocol works on this Layer. 

Session Layer

it is responsible for creating , maintaining and terminating sessions. (NetBIOS) protocol works on this Layer. 

Presentation Layer

it is responsible for translation , compression, encryption. (SSL, MIME) protocol works on this Layer.

Application Layer

it is responsible for actual form of data. (HTTP, DNS, POP3, SMTP) protocol works on this Layer. 

Note

Protocol

it is set of rules. with the help of this devices communicate with each other.

MAC-Media Access Control

LLC-Logic Link Control

TCP-Transmission Control Protocol

UDP-User Datagram Protocol

IP-Internet Protocol

NetBIOS- Basic Input Output System Network

SSL-Secure Socket Layer.

MIME- Multipurpopse Internet Mail Extension

HTTP-Hypter Text Transfer Protocol

SMTP- Simple Mail Transfer Protocol

POP3- Post Office Protocol Version -3

DNS- Domain Name System .