Chapter 2

Question 1

Define Encapsulation

Answer 1

The process of encoding data as it goes down the OSI stack. p. 28

Question 2

Define reference model.

Answer 2

A conceptual blueprint of how communications should take place. p. 28

Question 3

What are some advantages of using the OSI layered model?

Answer 3

It divides the network comunication process into smaller and simpler components.
It allows multiple vendor development thorugh standardization of network components
It encourages industry standardization
It allows various types of hardware to be used. p. 29

Question 4

What are the 7 layers of OSI?

Answer 4

Application
presentation
session
transport
network
data link
physical p. 30

Question 5

What do the top three layers of the OSI model do?

Answer 5

Define how the applications within the end statiosn will communicate with each other and with users. p. 31

Question 6

What do the bottom four layers of the OSI model do?

Answer 6

Define how data is transmitted end to end. p. 31

Question 7

What happens at the Application layer?

Answer 7

The spot where users communicate with teh computer. It chooses and determines the availability of communicating partners along with the resources necessary to make the connection. p. 31

Question 8

What happens at the Presentation layer?

Answer 8

It presents data to the application layer. p. 33

Question 9

What happens at the Session layer?

Answer 9

Responsible for setting up managing and then tearing down sessions between presentation layer entitites. Also provides dialog control between devices or nodes. It coordinates communication between systems in three modes. p. 33

Question 10

What happens at the Transport layer?

Answer 10

segments and reassembles data into a data stream. Provides end to end data transport servicdes and can establish a logical connection between the sending host and destination host on an internetwork. p. 33

Question 11

What happens at the Network Layer?

Answer 11

Manages devides addressing, tracks the location of devices on the network and determines the best way to move data. p. 39

Question 12

What happens at the Data Link layer?

Answer 12

provides physical transmission of the data and handles error notification, network topology, and flow control. p. 42

Question 13

What happens at the Physical layer?

Answer 13

Sends bits and recieves bits. p. 44

Question 14

true or false: If you uninstall the TCP/IP network card you can still use Internet Explorer to view an HTML document?

Answer 14

True p. 31

Question 15

true or false: Microsoft word lies within the application layer.

Answer 15

False, it interfaces with the application layer protocols. p. 32

Question 16

What are the three modes of the session layer?

Answer 16

Simplex, half duplex, and full duplex p. 33

Question 17

What are two protocols that work at the session layer?

Answer 17

TCP and UDP p. 33

Question 18

Define virtual circuit.

Answer 18

When a host transmits down the model the senders TCP process contacts the destinations TCP process to establish a connection. This type of communication is known as connection oriented. p. 34

Question 19

What happens during the initial handshake of the TCP process?

Answer 19

The two TCP process agree on the amount of information that will be sent in either direction before teh recipient TCP sends back and acknowledgement. p. 34

Question 20

What happens at the session layer if a machine recieves a flood of datagrams too quickly for it to process?

Answer 20

It stores them in a memory section called a buffer. p. 35

Question 21

What are some network devices that work at all layers of the OSI model?

Answer 21

Network managemtn stations
Web and application servers
Gateways
Network hosts p. 39

Question 22

What are some network devices that work primarily at the physical layer of the OSI model?

Answer 22

Network interface cards
Transceivers
Repearters
Hubs

Question 23

What are two types of packets used at the network layer?

Answer 23

Data packets

Route update packets

Question 24

What are data packets used for?

Answer 24

They transport user data throught he internetwork. Protocols used to support data traffic are called routed protocols. ie IP and IPv6

Question 25

What are Route update packets used for?

Answer 25

Used to update neighboring routers about the networks conected to all routers within the internetwrok. p. 40