OSI Model

Question 1

L1

Answer 1

Physical
This layer conveys the bit stream through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier.

Question 2

L2

Answer 2

Data Link
This layer provides synchronization for the physical level. It furnishes transmission protocol knowledge and management.

Question 3

L3

Answer 3

Network
This layer handles the routing of the data (sending it in the right direction to the right destination on outgoing transmissions and receiving incoming transmissions at the packet level). The network layer does routing and forwarding.

Question 4

L4

Answer 4

Transport
This layer manages the end-to-end control (for example, determining whether all packets have arrived) and error-checking. It ensures complete data transfer.

Question 5

L5

Answer 5

Session
This layer sets up, coordinates, and terminates conversations, exchanges, and dialogs between the applications at each end. It deals with session and connection coordination.

Question 6

L6

Answer 6

Presentation
This is a layer, usually part of an operating system, that converts incoming and outgoing data from one
presentation format to another (for example, from a text stream into a popup window with the newly arrived text). Sometimes called the syntax layer.

Question 7

L7

Answer 7

Application
This is the layer at which communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified.
(This layer is not the application itself, although some applications may perform application layer functions.)