ASSIGNMENT NO 1st
M.NOMAN ARSHAD
BSIT-F13-LC-08
MISS SUBEEN
UNIVERSITY OF SARGODHA
A comparison of Network Models TCP/IP & OSI .
There are two network models that describe how networks 'work'. The OSI Model, the older model, was designed for the OSI protocol stack. While different organizations were battling over standards, Vint Cerf and Bob Khan worked out the TCP/IP software from which the TCP/IP Model was co-designed. The diagram below shows how the two networking models compare, and how the logical and physical networking protocols relate to the layers in each of the two models. -
There are seven layers in the OSI Model, only four in the TCP/IP model. This is because TCP/IP assumes that applications will take care of everything beyond the Transport layer. The TCP/IP model also squashes the OSI's Physical and Data Link layers together into the Network Access Layer. Internet Protocol really doesn't (and shouldn't) care about the hardware underneath, so long as the computer can run the network device and send IP packets over the connection.
The TCP/IP Network Model.
The TCP/IP network model has four basic layers:
Network interface (layer 1): Deals with all physical components of network connectivity between the network and the IP protocol
Internet (layer 2): Contains all functionality that manages the movement of data between two network devices over a routed network
Host-to-host (layer 3): Manages the flow of traffic between two hosts or devices, ensuring that data arrives at the application on the host for which it is targeted
Application (layer 4): Acts as final endpoints at either end of a communication session between two network hosts
The OSI Network Model.
Physical (Layer 1)
This layer conveys the bit stream - electrical impulse, light or radio signal -- through the network at the electrical and
