OSI Data Link Layer: MAC Techniques

Question 1

Methods of Shared MAC Media

Answer 1

• Controlled Access
• Contention-based Access

Question 2

A method of Shared MAC media wherein only one device transmits at a time; devices wanting to transmit must wait for their turn

Answer 2

Controlled Access

Question 3

A method of Shared MAC media wherein devices can transmit at the same time

Answer 3

Contention-based Access

Question 4

Mechanisms that resolve contention

Answer 4

• CSMA/CD for Ethernet Networks
• CSMA/CD for 802.11 Wireless Networks

Question 5

Contention-based Access for Shared Media uses what process to first detect whether the media is carrying a signal

Answer 5

Carrier Sense Multiple Access (CSMA)

Question 6

Other name for Controlled Access for Shared Media

Answer 6

Scheduled Access or Deterministic

Question 6

Other name for Contention-Based Access for Shared Media

Answer 6

• Non-deterministic

Question 7

What is CSMA/CD

Answer 7

Contention-Based Access for Shared Media/Collision Detect

Question 7

It is a CSMA method that monitors the media for the presence of a data signal

Answer 7

CSMA/CD

Question 8

What is CSMA/CA

Answer 8

Contention-Based Access for Shared Media/Collision Avoid

Question 9

It refers to an arrangement of the nodes and the physical connections between them

Answer 9

Physical Topology

Question 9

It is a CSMA method that examines the media for the presence of a data signal (?)

Answer 9

CSMA/Collision Avoid

Question 10

It refers to the way a network transfers frames from one node to the next

Answer 10

Logical Topology

Question 11

How is MAC implemented in a point-to- point topology

Answer 11

It connects two nodes directly so MAC protocol can be very simple; all frames on the mediacan only travel to or from two nodes

Question 12

How is MAC implemented in a Multiaccess Topology

Answer 12

It enables a number of nodes to communicate by using the same shared media

Question 13

How is MAC implemented in a Ring topology

Answer 13

Each node in turn receives a frame and uses a controlled MAC technique token passing

Question 14

Three Parts of a Frame

Answer 14

Header
Data
Trailer

Question 15

Device addresses in layer 2 are referred to as what?

Answer 15

Physical Addresses

Question 16

Frame header fields

Answer 16

Start of Frame Field
Source and Destination address fields
Priority/Quality of Service Field
Type Field
Logical Connection control field
Physical link control field
Flow control field
Congestion Control Field

Question 17

Frame trailer fields

Answer 17

Frame Check Sequence Fields
Stop Field

Question 18

Process that refers to the determination of whether the frame arrived without error

Answer 18

Error Detection

Question 19

It refers to creation of a logical summary contents of the frame by the transmitting node

Answer 19

Cyclic Redundancy Check

Question 20

Ethernet Frame fields

Answer 20

Preamble
Destination Address
Source Address
Type
Data or Payload
Frame Check Sequence (FCS)

Question 21

Options that PPP can make within a session

Answer 21

• Authentication:
• Compression
• Multilink

Question 22

It is a method by PPP wherein it requires the nodes on each end of the PPP link to authenticate in order to establish communications over a point to point link

Answer 22

PPP Authentication

Question 23

It is a PPP method where in it reduces the size of a data framee transmitted over a network link

Answer 23

PPP Comprehension

Question 24

It is a PPP method wherein it uses multiple data links to send frames

Answer 24

Multilink