Chapter 2 OSI

Question 1

Name all 7 layers of the OSI

Answer 1

physical
data link
network
transport
session
presentation
application

Question 2

What is Encapsulation?

Answer 2

The process of taking data from the previous layers and passing them onto the next, the reverse of this is DE-capsulation

Question 3

What is data called while it is on the top 3 layers of the OSI?( session, presentation, application )

Answer 3

DATA

Question 4

Data is referred to as what on the Transport layer?

Answer 4

Segments

Question 5

data from transport layer to network layer is now called?

Answer 5

PACKET

Question 6

From the Network to Data link layer data is turned into what?

Answer 6

FRAME

Question 7

From the Data link layer to the physical later data is turned into what?

Answer 7

BITS

Question 8

PHYSICAL LAYER - FIRST!!!!

Answer 8

• deals with all aspects of physically moving data from one computer to the next
• Translates data into 1’s & 0’s
• decides how data is encoded on the media used to transport the data ( coaxial, fiber optic etc )

Question 9

What devices are typically found on the physical layer?

Answer 9

Hubs, Wires

Question 10

DATA LINK LAYER - SECOND!!!!!

Answer 10

• moves data from one computer to another
• contains an addressing mechanism for finding the computer or other device on the shared network segment it is trying to communicate with

Question 11

What devices are typically found on the DATA link layer?

Answer 11

Switches

Question 12

What protocols are found here?

Answer 12

point to point protocol PPP and the Ethernet protocol

Question 13

Data link layer is split into two sublayers called?

Answer 13

Logical link control & Media access control

Question 14

what is the logical link sublayer?

Answer 14

is the creation of the IEEE 802.2 standard, which was created to facilitate communications between the upper network layer and the lower physical layer

Question 15

What is the Media access control sublayer?

Answer 15

one of the primary functions is to determine which computer has access to the network media at any given time. The “MAC” layer provides access control to the media as it implies. Also is responsible for determining where one frame begins and ends or “frame synchronization”

Question 16

TIME BASED FRAME SYNCHRONIZATION

Answer 16

places a specific amount of time between each frame in a stream of frames. After a set amount of time the computer knows where the frame ends and begins. Extra time can creep in and throw this off

Question 17

CHARACTER COUNTING

Answer 17

keeps track of how many characters in a frame

Question 18

BYTE STUFFING

Answer 18

uses a predefined set of bytes to start off a frame and uses a different set of predefined bytes to end a frame