Ch.2 Open Systems Interconnect (OSI) Reference Model

Question 1

Layer 7 of the OSI model

Answer 1

Application

Question 2

Layer 6 of the OSI model

Answer 2

Presentation

Question 3

Layer 5 of the OSI model

Answer 3

Session

Question 4

Layer 4 of the OSI model

Answer 4

Transport

Question 5

Layer 3 of the OSI model

Answer 5

Network

Question 6

Layer 2 of the OSI model

Answer 6

Data Link

Question 7

Layer 1 of the OSI model

Answer 7

Physical

Question 8

What do the upper 3 layers define in the OSI model?

Answer 8

the rules of how the applications working within host machines communicate with each other as well as with end users

Question 9

What do the bottom 4 layers of the OSI model define?

Answer 9

defines how the actual data is transmitted from end to end

Question 10

What are the upper 3 OSI layers?

Answer 10

Session, Presentation, Application

Question 11

What are the lower 4 OSI layers?

Answer 11

Physical, Data link, Network, Transport

Question 12

Moves bits between devices. Specifies voltage, wire speed, and pin-out of cables

Answer 12

Physical

Question 13

Combines packets into bytes and bytes into frames, Provides access to media using MAC addresses, Performs error detection but not correction

Answer 13

Data Link

Question 14

Provides logical addressing, which router user for path determination

Answer 14

Network

Question 15

Provides reliable or unreliable delivery, performs error correction before retransmit

Answer 15

Transport

Question 16

Keeps different applications data separate

Answer 16

Session

Question 17

Presents data, Handles processing such as encryption

Answer 17

Presentation

Question 18

Provides a user interface

Answer 18

Application

Question 19

Layer that deals with translating services and deals with tasks like data compression, decompression, encryption and decryption.

Answer 19

Presentation Layer

Question 20

Layer that is responsible for allowing multiple web browser sessions on your desktop at the same time

Answer 20

Session

Question 21

3 different The session layer uses to coordinate communications between systems

Answer 21

Simplex, half-duplex, full-duplex

Question 22

Mode of communication that can only communicate in one direction

Answer 22

Simplex

Question 23

Mode of communication that communicates both directions but only one direction at a time

Answer 23

half-duplex

Question 24

Mode of communication that can communicate bidirectional

Answer 24

full duplex

Question 25

Layer that involves reliable networking and deals with acknowledgments, sequencing and flow control

Answer 25

Transport layer

Question 26

Steps in a TCP handshake

Answer 26

1. The first “connection agreement” segment is a request for synchronization
2. the next segments acknowledge the request and establish connection parameters
3. Acknowledgement. notifies the destination host that the connection agreement has been accepted. Data transfer can now begin.

Question 27

short hand steps of TCP handshake

Answer 27

SYN, SYN/ACK, ACK