1. THE SEVEN LAYERS OF THE OSI MODEL

2. PHYSICAL LAYER Encodes the packets into a signal recognized by the medium that will carry them Ex. Analog signal sent over a telephone line

3. DATA LINK LAYER Calculates the checksum and keeps a copy

4. NETWORK LAYER Routes the message from sender to receiver. Splits the data segments from the transport layer into smaller groups of nits called packets

5. TRANSPORT LAYER (end to end layer) The basic function of the transport layer is to accept data from the session layer, break up the data into smaller units if need be, and send these manageable data packets to the network layer

6. SESSION LAYER Establishes and maintains communications

7. PRESENTATION LAYER Translates the converted message data into a language the receiving computer can process (from ASCII to EBCDIC)

8. APPLICATION LAYER Serves as an interface between the user and the network