O.S.I Model

                                o.s.i model

     ( osi model) it is the part of data transformation

osi model-it is the model define by( i.s.o.) which tells about flow of information from 

one system to another the whole model divided in 7 layer.

1. physical layer

2.data link layer

3.network layer

4.transport layer

5.session layer

6.presentation layer

7.application layer

every layer have different work i define it next session.

physical layer-it convert binary bits 

in to electrical or optical before transmitting

data & again converts the electrical signal into binary bits& reciving bit. it deals with media type transletions mode topology. the device work in this layer are hub & repeater.

data link layer- it recieving to data from network layer & convert them in to frames.

device on this layer switch & bridge. in this fram there are four block & each block consist their own data. first block have mac address, second block have net address , third block have data fourth have error code.

mac address- it is 48 bit physical address of machine ( nic card) it can not be changed by user

net work layer- it receive data from trans form layer & converting them into packet. the device on this layer router & brouter.

transport layer- it create segmentof data recived from session layer.

session layer- it create session for data transmission it establiss connection manage it & after transmission terminate the connection.

presentation layer- this layer decrypt to data. any  one don't open data .it give security to data.

application layer- all data display on screen in this layer