Provides end-to-end connectivity specifying how data should be formmated, addressed, transmitted, routed, and received at the destination. Protocols exist for a variety of different types of communication services between computers.
THE FOUR LAYER-MODEL OF TCP/IP MODEL
- APPLICATION LAYER
- TRANSPORT LAYER
- NETWORK LAYER
- NETWORK ACCESS LAYER
OSI MODEL
It is a way of sub-dividing a communications system into smaller parts called layers. Similar communication function are grouped into logical layers. A layer provides services to its upper layer while receiving services from the layer below. On eachy layer, an instance provides service to the instances at the layer above and requests service from the layer below.
