unit 5: networks

Question 1

what is digital convergence

Answer 1

gradual merger of computing and communications into a new information environment

same information is exchanged among many kinds of equipment, using the language of computers

Question 2

what is a digital signal

Answer 2

each signal is a bit

0s and 1s, off and on

All the data that a computer processes is a series of 0s and 1s

Question 3

what is an analog

Answer 3

most phenomena in life are analog

Analog signals use wave variations, continuously changing

Sound, light, and temperature are analog forms

Traditional TV and radio use analog signals

Humans’ vision operates in analog mode

analog data can be converted into digital formed

Question 4

what is a modem

Answer 4

needed to convert analog data into digital data that computers can use

For data transmission over telephone lines and cables

Modems can convert data by modulating either a analog wave’s amplitude or its frequency

Question 5

steps of modem transmitting data

Answer 5

1. Modems modulate (convert) a computer’s digital data to analog data
2. transmit data
3. then demodulate (reconvert) it back to digital data for the receiving computer

Question 6

what is a network

Answer 6

system of interconnected computers, telephones, and/or other communications devices

communicate with one another and share applications and data

Question 7

what are the benefits of networks

Answer 7

Share peripheral devices, such as printers, scanners, disk drives

Share software

Share data and information

Better communications

Accessing databases

Centralized communications

Security of information, because of improved backup systems

Question 8

what are the types of networks

Answer 8

wide area networks (WAN)

metropolitan area network (MAN)

local area network (LAN)

Question 9

wide area networks (WAN)

Answer 9

Communications network that covers a wide geographic area, such as a country or the world

Most long-distance and regional telephone companies

WANs are used to connect local area networks

best example of a WAN is the Internet

use common carrier that is telecommunication company that hires itself for public for communication transmission services

Question 10

metropolitan area network (MAN)

Answer 10

Communications network covering a city or a suburb

Many cellphone systems are MANs

use common carrier that is telecommunication company that hires itself for public for communication transmission services

Question 11

local area network (LAN)

Answer 11

Connects computers and devices in a limited geographic area

ex: one office, one building, or a group of buildings close together

basis for most office networks, and the organization that runs the LAN owns it

Question 12

how are networks structured (two types)

Answer 12

client/server

peer to peer

Question 13

client/server network structure

Answer 13

clients: computers that request data
servers: computers that supply data

File servers act like a network-based shared disk drive

Database servers store data but don’t store programs

Print servers connect one or more printers and schedule and control print jobs

Mail servers manage email

Question 14

peer to peer network structure

Answer 14

All computers on the network are “equal”

communicate directly with one another without relying on servers

Question 15

intranets

Answer 15

use infrastructure and standards of the Internet and the web

for an organization’s internal use only

Question 16

extranets

Answer 16

milar to intranets but allows use by selected outside entities (suppliers)

Question 17

VPNs (virtual private network)

Answer 17

use a public network (usually the Internet)

intranets and extranets to connect an organization’s various sites but on a private basis

via encryption and authentication

regular Internet users do not have access to the VPN’s data and information

Question 18

firewalls

Answer 18

intranets, extracts and VPN use this for security

system of hardware and/or software that protects the system from intruders

Question 19

network components

Answer 19

all have something in common

wired = twisted-pair, coaxial cable, fiber-optic cable

wireless = infrared, microwave, radio, Wi-Fi, satellite

hosts and nodes

packets

protocols

Question 20

hosts and nodes

Answer 20

Client/server network has a host computer that controls network

node is any device attached to the network

Question 21

packets

Answer 21

fixed-length blocks of data for transmission

reassembled after transmission

carries four types of information that will help protocol get to its destination

Question 22

protocols

Answer 22

set of conventions, or rules

governs the exchange of data between hardware and/or software components in the network; built into the hardware or software you are using

specifies how receiver devices will acknowledge sending devices (handshaking)

specify the type of electronic connections used

specify timing of message exchanges

specify error-detection techniques

Question 23

what does handshaking in protocols establish

Answer 23

the circuit is available and operational

the level of device compatibility and the speed of transmission

Question 24

packet’s four types of info to help protocol get to destination

Answer 24

1. the sender’s address (IP)
2. the intended receiver’s address
3. how many packets the complete message has been broken into
4. the number of this particular packet.

The packets carry the data in the protocols that the Internet uses—that is, TCP/IP

Question 25

what are the network linking devices

Answer 25

switch

bridge

gateway

router

backbone

NIC (Network interface card)

NOS (network operating system

Question 26

switch in network linking devices

Answer 26

Device that connects computers to a network

sends only to intended recipients

operates back and forth at the same time

Question 27

bridge in network linking devices

Answer 27

interface device that connects same type of networks

Question 28

gateway in network linking devices

Answer 28

Interface device that connects dissimilar networks

Question 29

router in network linking devices

Answer 29

Device that directs messages among several networks, wired or and/or wireless

Question 30

backbone in network linking devices

Answer 30

Main Internet highway that connects all networks in an organization

includes switches, gateways, routers, etc.

Question 31

NIC (Network interface card) in network linking devices

Answer 31

inserted in a slot on the motherboard

Question 32

NOS (network operating system in network linking devices

Answer 32

the system software that manages network activity

Question 33

network topology, what is it

Answer 33

The layout (shape) of a network

Question 34

what does the network topology include

Answer 34

star

ring

bus

tree

mesh

Question 35

star in network topology

Answer 35

all nodes are connected through a central network switch

Question 36

ring in network topology

Answer 36

all nodes are connected in a continuous loop

Question 37

bus in network topology

Answer 37

all nodes are connected to a single wire or cable

Question 38

tree in network topology

Answer 38

a bus network of star networks

Question 39

Mesh in network topology

Answer 39

messages sent to the destination can take any possible shortest, easiest route to reach its destination

must be at least two paths to any individual computer to create a mesh network

Question 40

ethernet

Answer 40

Network standard for linking all devices in a local area network

describes how data can be sent between computers and other networked devices usually in close proximity

deals with LAN collisions

is a LAN technology that can be used with almost any kind of computer

Ethernet communications protocol is embedded in software and hardware devices intended for building a local area network (LAN)

commonly used in star topologies