Module 6. 1 - Data Link Layer

Question 1

what layer is data link layer

Answer 1

layer 2

Question 2

data link layer is responsible for? Explain

Answer 2

NIC to NIC communications
-DLL enables upper layers to access physical media but completely unaware of how data is being transmitted
- DLL accepts layer 3 packets from network layer and encapsulates them into layer 2 frames
- controls how data is placed and received to ensure smooth communication over any network
- exchanges frames between endpoints over the network media
-receives encapsulated data from physical medium , decapsulate and pass and forwards it to the upper layer protocols
- performs error detection and rejects any corrupt frames

Question 3

node device

Answer 3

physical device that connects to a networks and can receive, create, store, or forward data along a communications path

Question 4

importance of data link layer

Answer 4

to make the network layer and above operate consistently over diverse network setups

Question 5

without data link layer

Answer 5

network layer and above would have to adapt to every connecting type of media that exists along a delivery path

Question 6

sublayers of IEEE 802 standards

Answer 6

Logical Link Control
Media Access Control

Question 7

LLC

Answer 7

handles the connection between the software and hardware, letting different network protocols use the same network.

Question 8

MAC

Answer 8

ensures devices don’t collide when sending data, and provides device-specific address (MAC address)

Question 9

MAC sublayer data encapsulation

Answer 9

Frame delimiting, addressing, error detection

Question 10

hop along path function for providing access to media

Answer 10

Accepts a frame from a medium
Decapsulate the frame
Re-encapsulates the packet into a new frame
Forwards the new frame appropriate to the medium of that segment of the physical network

Question 11

maintains the protocols and services for the TCP/IP

Answer 11

Internet Engineering Task Force (IETF)

Question 12

Engineering organizations that define open standards and protocols that apply to the network access layer

Answer 12

-Institute of Electrical and Electronics Engineers (IEEE)
-International Telecommunications Union (ITU)
-International Organization for Standardization (ISO)
-American National Standards Institute (ANSI)