1.1 - Understanding the OSI Model

Question 1

Name the OSI model in order (bottom to top).

Answer 1

Layer 7: Application
Layer 6: Presentation 
Layer 5: Session
Layer 4: Transport 
Layer 3: Network
Layer 2: Data Link
Layer 1 : Physical

Question 2

What is the one of the abbreviations used to reference the OSI model layers?

Answer 2

Please Do Not Throw Sausage Pizza Away

P / D / N / T / S / P / A

Question 3

What is layer 1? And what happens at this layer?

Answer 3

“Physical” layer. This layer deals with the physics of the network such as:

-signaling, cabling, connecters

Question 4

What is layer 2? And what happens at this layer?

Answer 4

“Data Link” layer. The switching layer, which pertains to MAC addresses on ethernet. Basic network “language.”

Question 5

What is layer 3? And what happens at this layer?

Answer 5

The network/routing layer. Sending fragments of data to certain IP address across different networks.

Question 6

What is layer 4? And what happens at this layer and what does it refer?

Answer 6

Transport layer. Refer to as the post office layer - sorting out whether the data is TCP or UDP.

Question 7

What is layer 5? And what happens at this layer and the different protocols of sending data?

Answer 7

Session layer. This starts the communication between devices. Control and tunneling protocols. (Half/Full duplex)

Question 8

What is layer 6? And what happens at this layer?

Answer 8

Presentation layer. Responsible for delivery and formatting of info to the applications layer to further display for “humans.”

Question 9

What is layer 7? And what happens at this layer?

Answer 9

Application layer. What we see on the screen (HTTP, FTP, DNS, POP3).