1.3: COMPUTER NETWORKS, CONNECTIONS AND PROTOCOLS TRE fin Flashcards

1
Q

What is a LAN?

A

local area network

computers connected over a small area
uses own infrastructure

eg, home/small company networks

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2
Q

what is a WAN?

A

wide area network

connects computers over a large geographical area
uses third party hardware and cabling
>eg satellites, phone lines, fibre optic

eg, multi-national banking networks, internet

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3
Q

what is the internet?

A

the physical components that connect together to make a network of networks

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4
Q

what is the world wide web?

A

the software that runs on the internet (websites)

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5
Q

what is the cloud?

A

a (usually) remote compuer

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6
Q

why is an IP address needed?

A

each computer has a unique IP address which is needed to communicate with networks, etc

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7
Q

what is the maximum value of an IP address?

A

255, as 256 is a binary number

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8
Q

what does a domain name system (DNS) do?

A

allows you to type a name into your browser

this then translates the web address(URL) into an IP address

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9
Q

how many DNS ‘root’ servers are there and what do they do?

A

there are 13 DNS ‘root’ servers that hold all names and IP addresses
other DNS servers hold parts of the database

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10
Q

what is an ISP?

A

internet service provider

each one has a unique IP address and goes between your device and the internet

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11
Q

what is a network host?

A

a computer or other device connected to a network.which offers information, resources and applications to users

a host is needed to have a website

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12
Q

what is a domain name?

A

a URL

these are governed by a DNS which gives you autonomy over a small section of the internet

domain name registrars sell domain names to the public

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13
Q

what are the factors affecting network performance?

A

latency, bandwidth and error rate

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14
Q

what is latency?

A

the amount of time taken for a packet of data to get from one point to another
it is measured as the time required to get the data back to the sender

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15
Q

what is bandwidth?

A

the amount of data that can be transmitted in a fixed amount of time
it is expressed in beats per second (bps)

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16
Q

what is error rate?

A

the number of errors encountered during data transmission.
the higher the error rate, the less reliable the connection or data transfer is

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17
Q

what is a peer to peer network?

A

all computers have equal status, so all devices can act as a client or server and can provide network services

no additional hardware or software is needed for this sort of network

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18
Q

what is a client-server network?

A

relies on a central server and all clients request services from the server

additional hardware is needed- a high end, powerful server

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19
Q

what is needed to connect to a network?

A

switch
router
NIC

20
Q

what does a switch do?

A

allows many devices to connect
redirects data packets around the network

21
Q

what is a server?

A

the controlling computer

22
Q

what does the router do?

A

allows access to other networks and directs data packets to and from networks

23
Q

what is the NIC used for?

A

network interface card

used to connect to a network and contains the mac address

24
Q

what is a topology?

A

the ‘shape’ of a network
the way in which computers are connected

25
Q

what is a star topology?

A

all devices are connected to a central switch

usually a client server network

26
Q

what is a mesh topology?

A

full mesh: everything is connected to everything

partial mesh: most things are connected

usually set up as peer to peer

27
Q

what are the advantages of a star topology?

A

each machine can share resources (routers, printers, servers)

easy to add/remove machines from the network

if one machine fails, the network still works

28
Q

what are the disadvantages of a star topology?

A

equipment (switches, server, cables) are expensive
if the switch fails, all devices lose connection
all transmissions have to go through the central switch, which can be slow

29
Q

what are the advantages of a mesh topology?

A

faster,as data doesn’t have to run through a central switch
highly robust
data can be transmitted from several devices simultaneously

30
Q

what are the disadvantages of a mesh topology?

A

too many stations can make it slow down or crash

expensive to set up all the connections

it is hard to add more computers

31
Q

what is encryption?

A

a method of scrambling data to produce data that doesn’t make sense without access to the key

to read the data, the user is required to decrypt the data using the key

when using a secure site, SSL (secure socket layer) encryption is used which leads to HTTPS://

32
Q

what are the TCP/IP layers?

A

application layer -> transport layer -> internet layer -> network access layer

33
Q

what does the application layer do?

A

deals with the client, software and the protocols that need to be used (e.g mail, webpages)

34
Q

what does the transport layer do?

A

creates and sequences packets on the WAN , error checks packets and establishes the connection either one to one or one to many

35
Q

what does the internet layer do?

A

is responsible for addressing, packaging and routing functions

36
Q

what is the network access layer?

A

places TCP/IP packets on the network medium (wifi, cables, etc)

37
Q

what are the advantages of cloud?

A

-flexible storage

-you don’t have to purchase/ maintain expensive hardware

-the cloud provider is responsible for the security

-a cloud storage centre is more environmentally friendly than lots of individual servers

-you don’t need any network skills or maintenance workers

38
Q

what are the disadvantages of cloud?

A

-you need a reliable internet service to do anything

-you have no direct control over the security of your data

-there can be arguments over ownership

-you may be held responsible for any data security breaches even though you have no control over the security of the data z

39
Q

what is ethernet?

A

ethernet is a high-capacity wired network

40
Q

how does wifi work?

A

uses radio waves to transmit data

as long as a device has a wireless NIC, it can connect to a wireless network

wifi also has its own set of rules to manage data transmission

41
Q

what is bluetooth?

A

radio wave technology commonly used to connect devices within 10m of each other

42
Q

what is the different in transmission speed between wired and wireless transmissions?

A

wired: fast and consistent transmission speed

wireless: typically slower than cabled connections

43
Q

what is the difference between expansion of network (adding more devices) between wired and wireless transmissions?

A

wired: costly to add extra devices and cabling and switches may be required

wireless: easy to connect more devices, but more devices will share the same bandwidth and increase the network traffic

44
Q

what’s the difference between interference in wired and wireless transmissions?

A

wired: copper cable can be susceptible to magnetic or electrical interference, but fibre optic cable avoids this

wireless: signals can be reduced by walls and interference from other wireless devices, this affects the connection speed

45
Q

what’s the difference in signal strength between wired and wireless transmissions?

A

wired: ethernet cable maintains good strength under to 100m, fibre optic can be much longer

wireless: wireless hotspots are limited to a small local area and need repeater devices to expand the range

46
Q

what’s the difference in security between wired and wireless transmissions?

A

wired: data send along cables can’t be adult intercepted

wireless: wifi signals may be easily intercepted without adequate encryption security