Protocols

Question 1

How many layers in OSI model ?

Answer 1

7

Question 2

What is the application layer in OSI model ?

Answer 2

HTTPS HTTP FTP SMTP etc

Question 3

What is the role of the presentation layer of the OSI model ?

Answer 3

Translate binary to ASCII + Data Compression (lossy and lossless) + Encryption/Decryption

Question 4

What is the role of the session layer in the OSI Model ?

Answer 4

Manages the session. For example; Authentication and Authorisation. Overlooking & Managing the data packets for that session

Question 5

What is the role of Transport layer in OSI model ?

Answer 5

Segmentation(breaking down data into segments with a sequence number and port number), Flow Control(deciding the Mbps the data is sent at), Error Control(performs “checksum” to check no loss of data packets and resends if data packet was lost)

Question 6

What is the Network layer in the OSI model ?

Answer 6

Logical addressing(IP addressing of segments to and from), Path determination(deciding the fastest route for the packets to travel), Routing(sending the packets to the right network and end device via IP address on packets)

Question 7

What is the Data Link layer in OSI model ?

Answer 7

Assigns physical addressing to data packet segments (MAC address) to form a “frame” for the data packet. Performing encapsulation of data packets. Adding a header and tail to the data packet segments that are decapsulated by the router and encapsulated again before sending.

Also provides CSMA carrier sense multiple access; where it makes sure communication from devices on the same network do not have their data packets collide and cause error when trying to send to the media or receive from.

Question 8

What is the role of the physical layer in the OSI model ?

Answer 8

Physical layer converts the binary digits to the signal (media) it is being transmitted through. Radio waves, light pulses, electric currents.