LEC 1

Question 1

refers to information presented in whatever form
is agreed upon by the parties creating and using
the data

Answer 1

DATA

Question 2

are the exchange of data between two devices via some form of transmission medium such as a wire cable

Answer 2

Data Communications

Question 3

Data Communications: Fundamental Characteristics

Answer 3

Delivery
Accuracy
Timeliness
Jitter

Question 4

The system must deliver data to the correct destination.

Answer 4

DELIVERY

Question 5

The system must deliver the data accurately.

Answer 5

ACCURACY

Question 6

The system must deliver data in a timely manner

Answer 6

TIMELINESS

Question 7

refers to the variation in the packet arrival
time. It is the uneven delay in the delivery of
audio or video packets

Answer 7

JITTER

Question 8

Components of Data Communications

Answer 8

Message
Sender
Receiver
Transmission Medium
Protocol

Question 9

the information (data) to be communicated.

Answer 9

MESSAGE

Question 10

the device that sends the data message.

Answer 10

SENDER

Question 11

the device that receives the message.

Answer 11

RECEIVER

Question 12

the physical path by which a message travels from sender to receiver.

Answer 12

TRANSMISSION MEDIUM

Question 13

a set of rules that govern data communications. It
represents an agreement between the
communicating devices.

Answer 13

PROTOCOL

Question 14

5 DATA REPRESENTATION

Answer 14

Numbers
Text
Images
Audio
Video

Question 15

represented as a bit pattern, a sequence of bits.

Answer 15

Text

Question 16

T/F

Different sets of bit patterns have been designed to represent text symbols.

Answer 16

True

Question 17

Each set is called a

____, and the process of representing symbols is called ______.

Answer 17

code

coding

Question 18

also represented by bit patterns.

Answer 18

NUMBERS

Question 19

However, a code such as ASCII is not used to represent numbers; the number is directly converted to a binary number to simplify mathematical
operations

Question 20

___ also represented by bit patterns. In its simplest
form, an image is composed of a matrix of pixels
(picture elements), where each pixel is a small dot. The size of the pixel depends on the resolution.

Answer 20

IMAGES

Question 21

refers to the recording or broadcasting of sound

or music. It is continuous, not discrete

Answer 21

AUDIO

Question 22

refers to the recording or broadcasting of a
picture or movie

either be produced as a continuous entity or it can be a combination of images

Answer 22

VIDEO

Question 23

format of data block. the order in which they are presented

Answer 23

SYNTAX

Question 24

refers to the meaning of each section of bits; how a particular pattern is interpreted, and what action is to be taken based on that interpretation

Answer 24

SEMANTICS

Question 25

speed and sequencing. Refers to two characteristics: when data should be sent and how fast they can be sent

Answer 25

TIMING

Question 26

not approved but widely adopted

Answer 26

de facto (in practice)

Question 27

approved by an organization

Answer 27

de jure ( in law)

Question 28

direction of data flow: ____ one direction only

Answer 28

simplex

Question 29

direction of data flow: ____ both directions. one at a time

Answer 29

half duplex

Question 30

direction of data flow: ____ both directions. simultaneously

Answer 30

full duplex

Question 31

a set of devices connected by media links

Answer 31

networks

Question 32

T/F | EBCDIC is an 8-bit character encoding used mainly in IBM Mainframe

Answer 32

True

Question 33

point to point connection examples: telephone, two-way radio (walkie-talkie)

Answer 33

------

Question 34

Most popular approach for wireless communication

Answer 34

multipoint connection examples: voice over IP / IP telephony

Question 35

____ physical or logical arrangement of devices

Answer 35

TOPOLOGY

Question 36

fully connected mesh

Answer 36

``` pros: dedicated links robustness privacy easy to idnetify fault ``` cons: a lot of cabling i/o ports difficult to move

Question 37

star topology

Answer 37

``` pros: one i/o port per device little cabling easy o install robustness easy to identify fault ``` cons: single point of failure more cabling required

Question 38

____ data is broadcasted to every one of its ports

Answer 38

HUB

Question 39

____ knows exactly which port to send the data

Answer 39

SWITCH

Question 40

BUS TOPOLOGY

Answer 40

pros: little cabling easy to install cons: difficult to modify break in the bus cable stops all transmission

Question 41

can be unidirectional or bidirectional

Answer 41

RING TOPOLOGY

Question 42

RING TOPOLOGY

Answer 42

PROS: easy to install easy to identif fault cons: delay in large ring break in the ring stops all transmission

Question 43

network in a single office, building, or campus

Answer 43

LAN (LOCAL AREA NETWORK)

Question 44

Network providing long-distance communication over a country

Answer 44

WAN (WIDE AREA NETWORKS)

Question 45

MAN (metropolitan area networks

Answer 45

Network extended over an entire city

Question 46

SWITCHING

Answer 46

dedicated circuits circuit switching packet switching

Question 47

Telephone switches establish circuits for communication

Answer 47

CIRCUIT SWITCHING

Question 48

Data are put into packets. | each stamped with source and destination

Answer 48

PACKET SWITCHING

Question 49

_____knows where to forward packets

Answer 49

routers

Question 50

devices capable of communicating in several standards

Answer 50

gateways / routers

Question 51

Two or more networks connected become an | _______.

Answer 51

internetwork / internet

Question 52

largest internetwork in the world devices communicationg with TCP ./ IP protocol suite

Answer 52

internet