2. Application Layer -
DNS, HTTP, Browser

3. Presentation Layer -

4. Session Layer -
Web browser)

5. Transport Layer -
checksum
End-to-end)
Port)

6. Network Layer -
-
-
Network

7. Data Link Layer -
ACK
(Acknowledge) ACK
NAK (Negative Acknowledge)

8. Physical Layer -
-
Connector) RS-232-
C pin)
Shield Twisted Pair (STP), Unshield
Twisted Pair (UTP), Fibre Optic