Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CompSci > 3.9 Fundamentals of communication and networking > Flashcards

3.9 Fundamentals of communication and networking Flashcards

1
Q

synchronous transmission

A

streams of bits are transferred over a communication channel at a constant rate, transmitter and receiver are synchronised using a clock signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

asynchronous transmission

A

no clock signal so start and stop bits are used to control communication, data is transmitted when available, channel can be idle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

serial transmission

A

data bits are sent one after the other over a single wire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

parallel transmission

A

several bits are sent at the same time over their own wires

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

parallel transmission disadvantages

A

only works over short distances and with lower bit rates due to skew and crosstalk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

crosstalk

A

transmitting corrupted data due to electromagnetic interference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

skew

A

when bits are transmitted across parallel links at different speeds so fall out of sync

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why serial transmission is preferred over parallel transmission

A

serial transmission can operate at higher bit rates and transmitting over longer distances and uses fewer wires

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

bit rate

A

the number of bits that are transmitted over a channel each second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the higher the bit rate

A

the faster the data arrives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

baud rate

A

number of times that the signal changes per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

why are bit rate and baud rate sometimes different?

A

a symbol doesn’t always encode one bit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

bit rate (when different to baud rate)

A

baud rate x symbol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

baud rate (when different to bit rate)

A

bit rate/ symbol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

bandwidth

A

maximum rate of data transfer of a communication channel, directly proportional to bit rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how are bandwidth and bit rate directly proportional?

A

the greater the amount of data that can be transmitted over a channel, the more bits can be transmitted per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

latency

A

the delay from the time that a signal is sent to the time that it is received

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

protocol

A

a set of rules that determine the communication between devices to set the standards of the communication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

physical network topology

A

refers to the actual architecture of a network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

physical star network topology characteristics

A

each client has its own direct connection to a central hub, hub receives packets for all clients and delivers them to its recipient, server can be added

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

physical star network topology advantages

A

packets sent directly to recipient so no one else can access, easy to add and remove clients, each cable has one device so eliminates collisions, failure of one cable does not affect the rest of the network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

physical star network topology disadvantages

A

if central hub fails all communication is stopped, expensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

physical bus topology

A

connects clients to a single cable called backbone, a server can be connected to backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

physical bus topology advantages

A

no central hub so less chance of network failure, cheap to install

25
Q

physical bus topology disadvantages

A

packets are sent through backbone so all clients can see, collisions are likely to happen, if backbone fails entire network is unusable

26
Q

logical network topology

A

refers to the flow of data packets within a network

27
Q

logical bus network

A

delivers packets to all clients on the network

28
Q

logical star network

A

delivers packets only to their recipient

29
Q

what can be used to make a physical star network behave as a logical bus?

A

a bus protocol

30
Q

server

A

a program on a computer that shares resources with or provides services to any authorised client

31
Q

client

A

a program that runs on a device used by an end-user

32
Q

client-server networks process

A

a client sends a request to the server, the server processes the request and sends a response back to the client

33
Q

peer-to-peer networks

A

no central servers, peers can share resources and hardware, peers gives permission to access resources, equal status, computers must be switched on to share

34
Q

client-server vs peer-to-peer: setup cost

A

client-server: servers will need to be set up and configured, peer-to-peer: no additional devices

35
Q

client-server vs peer-to-peer: physical security

A

client-server: servers can be located in rooms which can be monitored, peer-to-peer: workstations may be at multiple locations so it is hard to oversee

36
Q

client-server vs peer-to-peer: backups

A

client-server: easy to make sure files are backed up, peer-to-peer: individual users are responsible for backing up their own data

37
Q

client-server vs peer-to-peer: points of failure

A

client-server: if a server fails, many users will be affected, peer-to-peer: if one device fails, it will not impact many

38
Q

personal area network (PAN)

A

connected devices that are located within a few metres of each other

39
Q

local area network (LAN)

A

single network that is located in a small geographical area

40
Q

wide area network (WAN)

A

network that connects two or more networks over a wider geographical area

41
Q

three types of wireless security protocols

A

WEP, WPA WPA2

42
Q

Wired Equivalent Privacy (WEP)

A

symmetric encryption algorithm, same key to encrypt and decrypt data

43
Q

WEP disadvantages

A

keys are too short and can be easy to decipher

44
Q

WiFi Protected Access (WPA)

A

generates a new encryption key for each data packet, requires a password to connect

45
Q

WPA2

A

each message is encrypted several times depending on key size

46
Q

SSID letters stand for

A

service set identifier

47
Q

service set identifier (SSID)

A

string of alphanumeric characters specific to a wireless network to identify it

48
Q

disabling SSID broadcast

A

stops wireless devices within range from displaying that the network is available so only those who know the SSID can connect

49
Q

disabling SSID broadcast disadvantage

A

even hidden SSIDs can be found

50
Q

media access control (MAC) address filter

A

whitelists can be created to allow specific devices to connect, blacklists can be used to block specific devices from connecting

51
Q

wireless access point (WAP)

A

WLAN is based around this central communications device

52
Q

WiFi

A

wireless local area network that is based on international standards

53
Q

CSMA/CA letters stand for

A

carrier sense multiple access with collision avoidance

54
Q

purpose of CSMA/CA

A

it is a protocol used in wireless networks to avoid data collisions caused by multiple devices communicating simultaneously

55
Q

CSMA/CA process

A

when a device is ready to transmit, it listens to communication channel to check whether it is idle, if so, data is transmitted, if channel is busy the node waits for a random period of time before checking channel again

56
Q

CSMA/CA disadvantage

A

hidden nodes may interfere with data transmission as they are undetected

57
Q

RTS/CTS stands for

A

request to send/clear to send

58
Q

purpose of RTS/CTS

A

to overcome the hidden node problem

CompSci (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions