OSI Model (for final exam)

Question 1

Layer 1

Answer 1

1. Physical - Transmission and reception of raw bit streams over a physical medium - sends bits
   EX: DSL, USB

Question 2

Layer 2

Answer 2

2. Data link - Reliable transmission of data frames between two nodes connected by a physical layer - sends bits or frames
   EX: PPP, IEEE 802.2, L2TP

Question 3

Layer 3

Answer 3

3. Network - Structuring and managing a multi-node network, including addressing, routing and traffic control - sends packets or datagrams
   EX: IPv4, IPv6, IPsec, AppleTalk

Question 4

Layer 4

Answer 4

4. Transport - Reliable transmission of data segments between points on a network, including segmentation, acknowledgement and multiplexing - sends segments
   EX: TCP, UDP

Question 5

Layer 5

Answer 5

5. Session - Managing communication sessions, i.e. continuous exchange of information in the form of multiple back-and-forth transmissions between two nodes - sends data
   EX: RPC, PAP

Question 6

Layer 6

Answer 6

6. Presentation - Translation of data between a networking service and an application; including character encoding, data compression and encryption/decryption - sends data
   EX: ASCII, EBCDIC, JPEG

Question 7

Layer 7

Answer 7

7. Application - High-level APIs, including resource sharing, remote file access, directory services and virtual terminals - sends data
   EX: HTTP, FTP, SMTP