Chapter 2

Question 1

(OSI)stands for what? p28

Answer 1

Open Systems Interconnection (OSI)

Question 2

is the process of encoding data as it goes down the OSI stack. p28

Answer 2

Encapsulation

Question 3

is a conceptual blueprint of how communications should take place. It addresses all the processes required for effective communication and divides these processes into logical groupings called layers. p28

Answer 3

reference model

Question 4

If they’re developing a protocol for a certain layer, all they need to concern them- selves with is that specific layer’s functions, not those of any other layer.The technical term for this idea is called?p29

Answer 4

binding

Question 5

Advantages of using the OSI layered model include, but are not limited to, the following: p29

Answer 5

It divides the network communication process into smaller and simpler components, thus aiding component development, design, and troubleshooting.
It allows multiple-vendor development through standardization of network components.
It encourages industry standardization by defining what functions occur at each layer of the model.
It allows various types of network hardware and software to communicate
It prevents changes in one layer from affecting other layers, so it doesn’t hamper development and makes application programming easier.

Question 6

The OSI model has seven layers: p30

Answer 6

Application (Layer 7)
Presentation (Layer 6)
Session (Layer 5)
Transport (Layer 4)
Network (Layer 3)
Data Link (Layer 2)
Physical (Layer 1)

Question 7

Provides a user interface

Answer 7

Application

Question 8

Presents data

Handles processing such as encryption

Answer 8

Presentation

Question 9

Keeps different applications’

data separate

Answer 9

Session

Question 10

Provides reliable or unreliable delivery

Performs error correction before retransmit

Answer 10

Transport

Question 11

Provides logical addressing

which routers use for path determination

Answer 11

Network

Question 12

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

Answer 12

Data Link

Question 13

Moves bits between devices

Specifies voltage, wire speed,and pin-out of cables.

Answer 13

Physical

Question 14

After all of this required synchronization takes place, a connection is fully established and the data transfer begins. This virtual circuit setup is called?p34

Answer 14

overhead.

Question 15

What is a flow control?p35

Answer 15

Flow control provides a means for the receiver to govern the amount of data sent by the sender.

Question 16

What are some of the Flow Control protocols involved ensure that the following will be achieved: p35

Answer 16

The segments delivered are acknowledged back to the sender upon their reception
Any segments not acknowledged are retransmitted
Segments are sequenced back into their proper order upon arrival at their destination
A manageable data flow is maintained in order to avoid congestion, overloading, and data loss

Question 17

what happens when a machine receives a flood of datagrams too quickly for it to process? It stores them in a memory section called a what?p35

Answer 17

Buffer

Question 18

To summarize, a service is considered connection-oriented if it has the following characteristics: p36

Answer 18

A virtual circuit is set up (such as a three-way handshake).
It uses sequencing.
It uses acknowledgments.
It uses flow control

Question 19

The quantity of data segments (measured in bytes) that the transmitting machine is allowed to send without receiving an acknowledgment for them is called.p37

Answer 19

window

Question 20

a technique that requires a receiving machine to communicate with the transmitting source by sending an acknowledgment message back to the sender when it receives data. p38

Answer 20

positive acknowledgment with retransmission

Question 21

The following network devices operate at all seven layers of the OSI model:p39

Answer 21

Network management stations (NMSs)
Web and application servers
Gateways (not default gateways)
Network hosts

Question 22

These devices manipulate mainly the physical aspects of a network data stream (such as the voltages, signal direction, and signal strength). The most popular of these are the following:p39

Answer 22

Network Interface Cards (NICs)
Transceivers
Repeaters
Hubs

Question 23

What is a Network Layer.p39

Answer 23

manages device addressing, tracks the location of devices on the network, and determines the best way to move data, which means that the Network layer must trans- port traffic between devices that aren’t locally attached.

Question 24

Two types of packets are used at the Network layer: p40

Answer 24

Data packets

Route-update packets

Question 25

What are some points about routers that you should definitely commit to memory: p41

Answer 25

Routers, by default, won’t forward any broadcast or multicast packets
Routers use the logical address in a Network-layer header to determine the next hop router to forward the packet to.
Routers can use access lists, created by an administrator, to control security on the types of packets that are allowed to enter or exit an interface
Routers can provide Layer 2 bridging functions if needed and can simultaneously route through the same interface.
Layer 3 devices (routers, in this case) provide connections between virtual LANs (VLANs).
Routers can provide quality of service (QoS) for specific types of network traffic

Question 26

provides the physical transmission of the data and handles error notification, network topology, and flow control.p42

Answer 26

Data Link layer

Question 27

The Data Link layer formats the message into pieces, each called p42

Answer 27

data frame

Question 28

The IEEE Ethernet Data Link layer has two sublayers:p43

Answer 28

Media Access Control (MAC)

Logical Link Control (LLC)

Question 29

Physical layer, which does two important things: p44

Answer 29

It sends bits and receives bits