The Seven Layer OSI Model

Question 1

Application Layer

Answer 1

Interface between two applications, each on separate computers.

Question 2

Presentation Layer

Answer 2

Responsible for reformatting, compressing, and or encrypting data in a way that the application on the receiving end can read.

Question 3

Session Layer

Answer 3

Describes how data between applications is synced and recovered if messages don’t arrive intact at the receiving application.

Question 4

Transport Layer

Answer 4

transports Applications layer payloads from one application to the other. The two main Transport layer protocols are TCP and UDP

Question 5

Network Layer

Answer 5

Moves message from one node to another until they reach the destination host.

Question 6

What are layer 1 and layer 2 responsible for?

Answer 6

Interfacing with physical hardware only on the local network. The protocol at these layers are programmed into the firmware of a computer NIC’s and other networking hardware.

Question 7

Decapsulation

Answer 7

Removing a header and trailer from a lower layer’s PDU.

Question 8

What is the difference between a switch and a router?

Answer 8

A switch belongs to the LAN and a router belongs to 2 or more LANs. A host on a LAN cannot communicate with a host on another LAN w/o a router to manage that communication and stand as a gateway between those networks.