OSI protocol layers

first layer

• transport

• data link

• presentation

• application

second layer

• transport

• data link

• presentation

• application

third layer

• session

• data link

• physical

• application

fourth layer

• session

• transport

• physical

• application

fifth layer

• session

• transport

• network

• application

sixth layer

• session

• transport

• network

• data link

seventh layer

• physical

• transport

• network

• data link

converts bits into an effect that can be sent e.g. light / radio signal

• transport layer

• applications layer

• physical layer

• data link layer

opens a connection between 2 WANs

• session layer

• applications layer

• physical layer

• data link layer

ensures information is presented in a human-friendly way

• session layer

• applications layer

• physical layer

• data link layer