OSI Model

Question 1

What does OSI stand for in OSI Model?

Answer 1

Open Systems Interconnection.

Question 2

What does the OSI provide?

Answer 2

A standard for different computer systems to be able to communicate with each other.

Question 3

What are the seven layers of the OSI?

Answer 3

7. Application Layer.
8. Presentation Layer.
9. Session Layer.
10. Transport Layer.
11. Network Layer.
12. Datalink Layer.
13. Physical Layer.

Question 4

What is the application layer (7) of OSI?

Answer 4

Human computer interaction layer, where applications can access network services.

Question 5

What does the presentation layer (6) of OSI do?

Answer 5

Ensures that data is in a usable format and is where data encryption occurs.

Question 6

What does the session layer (5) of OSI do?

Answer 6

Maintains connections and is responsible for controlling ports and sessions.

Question 7

What does the transport layer (4) of OSI do?

Answer 7

Transmits data using transmission protocols including TCP and UDP.

Question 8

What does the network layer (3) of OSI do?

Answer 8

Decides which physical path the data will take.

Question 9

What doe the datalink layer (2) of OSI do?

Answer 9

Defines the format of data on the network.

Question 10

What does the physical layer (1) of OSI do?

Answer 10

Transmits raw bit stream over the physical medium.

Question 11

How is the OSI model useful?

Answer 11

Troubleshooting network problems.

Question 12

What is the only layer that directly interacts with data form users in the OSI?

Answer 12

Application layer.

Question 13

What is the application layer responsible for in the OSI?

Answer 13

Protocols and data manipulation that the application software relies on to present meaningful data to the user.

Question 14

What are examples of application layer protocols?

Answer 14

HTTP, SMTP

Question 15

What is the presentation layer responsible for in the OSI?

Answer 15

Translation, encryption, and compression of data.

Question 16

What is the session layer responsible for in the OSI?

Answer 16

Opening and closing communication between two devices.

Question 17

How can the session layer help with synchronization of data transfer between devices?

Answer 17

Using checkpoints so in case of disconnect or crash, transfer can resume at checkpoint.

Question 18

What is the transport layer responsible for in the OSI?

Answer 18

End-to-end communication between two devices as well as flow control and error control.

Question 19

What does the transport layer do to the data before moving it from the session layer to the network layer?

Answer 19

Breaks it up into chunks called sessions.

Question 20

What is the transport layer on the receiving device responsible for?

Answer 20

Reassembling the segments into data the session layer can consume.

Question 21

What does flow control determine in the transport layer?

Answer 21

Optimal speed of transmission to ensure that a sender with a fast connection doesn’t overwhelm a receiver with a slow connection.

Question 22

What does error control do in the transport layer?

Answer 22

Ensures that the data received is complete, and requests a retransmission if it isn’t.

Question 23

What is the network layer responsible for in the OSI?

Answer 23

Facilitating data transfer between two different networks. Finding the best physical path for the data to reach its destination (routing).

Question 24

When is the networking layer unnecessary?

Answer 24

When the two communicating devices are on the same network.

Question 25

What does the network layer do on the senders device/

Answer 25

Breaks up segments from the transport layer into packets.

Question 26

What does the network layer do on the receivers device?

Answer 26

Reassembles packets.

Question 27

What is the datalink layer responsible for in the OSI?

Answer 27

Facilitating data transfer between two devices on the SAME network. Also, responsible for flow control and error control in intra-network communication.

Question 28

What does the datalink layer do with packets from the network layer?

Answer 28

Brakes them into smaller pieces called frames.

Question 29

What is the physical layer responsible for in OSI?

Answer 29

Converting data into bit streams (0s and 1s).

Question 30

What is the physical equipment involved in the physical layer?

Answer 30

Switches and cables.

Question 31

In the physical layer, what must both devices agree upon so that the 1s can be distinguished from the 0s on both devices?

Answer 31

The signal convention.