OSI Model

Question 1

• this layer is composed of the signal being transmitted, cabling, connectors, and hubs.
• the physical links that enable bit transmission between devices

Answer 1

Layer 1 - physical layer

PDU = bit

Question 2

• simple switches operate at this layer
• data is formatted and prepared for transmission
• typically includes error detection and correction to ensure reliable delivery of data

Answer 2

Layer 2 - data link layer

PDU = frame (if using Ethernet)

Question 3

• Layer responsible for logical addressing
• provides connectivity and path selection between two host systems
• fragments packets to be sent across network

Answer 3

Layer 3 - network layer

PDU = packet

Question 4

• segmentation, transfer, and reassembling of data between end devices happens here
• common to use TCP and/or UDP

Answer 4

Layer 4 - transport layer

PDU = segment of TCP and data gram of UDP

Question 5

• establishes, manages, and terminates sessions between two communicating hosts
• synchronizes dialog between presentation layer of two hosts and manages data exchange

Answer 5

Layer 5 - session layer

Question 6

• translates lower level data into a format the application layer can use
• character encoding happens at this layer

Answer 6

Layer 6 - presentation layer

Question 7

• does not provide services for any other OSI model layer

* provides network services to the applications of the user

Answer 7

Layer 7 - application layer