Required a layered structure
Why ?
– Computer network is a complicated task.- It’s easier to implement a complicated task by breaking it to several simple tasks – A simple task is done by a layer- The result of the layer will be passed to the next layer
- The next layer use this result and perform a task and pass the result to the next
The layer approach for computers network is describe by the following two standards :
1. OSI (Open System Interface) Reference model.
-> 7 layer (this is academic not implemented)
2.TCP (Transport Communication Protocol)/IP (Internal Protocol)
-> 5 layer (this is used in the internet)
