module 6

Question 1

data communication system

Answer 1

eletronic transfer of data from one location to another

Question 2

major components of data communication system

Answer 2

sender and receiver devices
modems or routers
a communication channel

Question 3

bandwidth

Answer 3

the amountof data that can be transferred from one point to another in 1 second

Question 4

attenuation

Answer 4

loss of power in a signal as it travels from the sending device to the receving device

Question 5

communication media

Answer 5

connect the sender and receiver devices - can be conducted or radiated

conducted media: provides a physical path (cable) that signals are transmitted on
radiated media: use an antenna for transmitting data through air or water

Question 6

data transmission are divided in two types

Answer 6

broadband: multiple pieces of data sent simultaneously
narrowband: voice grade transmission that can transfer limited information in a specific period of time

Question 7

sender and recevier devices

Answer 7

input/output device
smart terminal
personal computer
netbook computer
supercomputer
smartphone

Question 8

modem

Answer 8

device that connects the user to the internet

Question 9

three types of processing configurations

Answer 9

centralized
decentralized
distributed

Question 10

centralized processing

Answer 10

all processing is done at one central computer

Question 11

decentralized

Answer 11

each user, department, or division has its computer
more responsive that a centralized processing system
high costs due to # of systems and duplication of efforts

Question 12

distributed processing

Answer 12

solves the problems that centralized and decentralized processing faced
processing is distributed

Question 13

Open Systems Interconnection model (OSI)

Answer 13

seven layer architecture
defines how data is transmitted from computer to computer
each layer performs a specific task

Question 14

seven layers an osi model

Answer 14

application
presentation
session
transport
network
data link
physical

Question 15

three major types of networks

Answer 15

local area networks (LAN)
wide area networks (WAN)
metropolitan area networks (MAN)

Question 16

LAN

Answer 16

connects workstations and peripheral devices in close proximity
used to integrate services within a limited geographical area

Question 17

WAN

Answer 17

can span several cities, states or countries
speed determiend by interconnections

Question 18

MAN

Answer 18

designed to handle data commincation for multiple orgs in a city

Question 19

five common topologies

Answer 19

star
ring
bus
hierarchal
mesh

Question 20

star

Answer 20

consists of central computer and nodes
host computer supplies the main processing power

Question 21

ring

Answer 21

no host computer required
each computer manages its own connectivity
arranged in a circle

Question 22

bus

Answer 22

connects nodes along a network segment
ends of the cable are not connected

Question 23

hierarchical

Answer 23

combines computers with different processing strengths
failure of nodes at the bottom level may not have a negative impact on network performance
middle and top nodes are crucial for network operations

Question 24

mesh

Answer 24

every node is connected to every other node
highly reliable
costly and difficult to maintain

Question 25

protocols

Answer 25

agreed upon methods and rules to exchange info applied to hardware connections, data transmission and file transfers specify the format of message packets

Question 26

routing

Answer 26

determining the route that data packet is transferred uses a routing table to determine the best route for the packet

Question 27

centralized routing

Answer 27

where one node is in charge of selecting the path for all packets

Question 28

distributed routing.

Answer 28

relies of each node to calculate the best possible route

Question 29

three levels of logic

Answer 29

presentation: focuses on how data is returned to the client application: focuses on software processing requests for users data management: focuses on data management and storage operations

Question 30

two tier architecture

Answer 30

client (tier 1) communicates. directly with the server (tier 2)

Question 31

N-tier architecture

Answer 31

works to balance the workload b/w the client and server removes the application logic from the client and server and places it on a middle-tier server

Question 32

wireless tech

Answer 32

wireless LANs (WLAN) wireless WANs (WWAN)

Question 33

WiMax

Answer 33

worldwide interoperability for microwave access designed for wireless MANs

Question 34

mobile networks

Answer 34

three part architecture: base stations mobile telephone switching offices subscribers

Question 35

techniques to improve security

Answer 35

include a service set identifier (SSID) use a wired equivalent privacy (WEP) use an extensible authntication protocol (EAP) use wifi protected access (WPA) use WPA2

Question 36

convergence

Answer 36

integration of voice, video and data to that multimedia info can be used fro decision making