Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Computer Science > Networks > Flashcards

Networks Flashcards

1
Q

Define Serial data transmission

A

when bits are sent one after another along the same data line

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

Define Parallel data transmission

A

several bits are sent simultaneously along separate lines or channels

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

what is skew and how is it caused

A

it is when data arrives unsynchronised , as each individual wire has slightly different properties bits travel at slightly different speeds along each of the wires

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

what is crosstalk and its problems

A

it refers to electromagnetic interference between two adjacent channels or parallel wires. It gets more pronounced as the frequency increases.

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

What type of transmission is preferred for long distances

A

serial transmission is reliable over very long distances at very high data transfer rates (frequencies)

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

At what distance can parallel transmission be used up to?

A

around 2m due to crosstalk

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

what is an example of a serial connector and its benefit

A

USB connecters are much smaller and cheaper than parallel connectors

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

define synchronous data transmission

A

all data transfers are timed to coincide with an internal clock pulse.

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

How is Data sent using synchronous transmission

A
  • The data is sent as one long stream with no gaps in transmission
  • The receiver counts the bits and reconstructs bytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Define asynchronous data transmission

A

each byte is sent seperately the moment it is available instead of waiting for a clock signal

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

How are bytes sent in asynchronous transmission

A

each byte is preceded by a start bit and ends with a stop bit or stop period - a short time gap between each set of bits

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

what is a parity bit

A

it is added as the 8th bit as a form of error detection, this bit is set to a 1 or 0 to make the total number of 1’s or 0’s in each byte odd or even depending on the machine

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

disadvantages and advantages to asynchronous transmission

A
  • relatively slow owing to the increased number of bits sent

* it is a cheap and effective form of serial transmission suited to low speed connections like a KnM

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

Define Latency

A

It is the time delay between the moment the first byte or packet of a communication starts and when it is received at its destination

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

Define protocol

A

The set of rules relating to communication between devices, all communications between devices require the devices agree on a format of the data.

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

what things do the protocol need to define

A
  • standards of physical connections
  • rate of transmission
  • data format
  • type of transmission a/synchronous
  • error checking procedures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define bit rate

A

the number of bits transmitted in one second over a wired or wireless data link

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

Define Baud rate

A

the rate at which the signal in a communications channel changes state

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

What is a baseband, and how are bits sent along it.

A

it carries one signal at a time, a bit is represented by a high or low voltage in the cable

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

Define Broadband

A

it carries multiple signals on a fixed carrier wave. bits are sent as variations on the wave

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

what is the formula for bit rate

A

bit rate = baud rate x number of bits per signal

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

Define Bandwidth

A

it is a measure of the maximum capacity of a communications channel

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

Define Local Area Network

A

two or more computers connected together within a small geographical area

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

what is a network topology

A

it is the arrangement of the various computing devices which make up a computer network

25
what is a bus topology
an arrangement where nodes are connected in a daisy chain by a single central communications Channel
26
what is a star topology
an arrangement where a central node or hub provides a common connection point for all other nodes
27
how does a bus network operate
* All nodes are connected to a backbone cable * Each end of the backbone is connected to a terminator which stops signals bouncing back * Each node is passive * Data is sent in one direction * Only one computer can transmit at one time
28
what protocol is used to enable nodes to transmit on the same cable
carrier sense multiple access (CSMA/CD)
29
What are advantages to a Bus topology
* Cheap * devices can easily be added * Good for small networks
30
What are disadvantages to a Bus topology
* Main cable is a point of failure * Limited cable length * Performance degrades with heavy use due to data collisions * Poor security
31
What does CSMA do
* It detects two nodes attempting to transmit simultaneously * Both nodes cease transmission and wait a random time (backing off mechanism)
32
Difference between a hub and switch
a switch sends communications to the specific computer it is intended for and a hub broadcasts the message to every computer on the LAN
33
How does a switch identify and locate where to send data
it holds the MAC addresses for each device connected to it and uses these to direct packets of data to the correct device
34
What are advantages to a star network
* Easy to isolate problems * Good performance * More secure if a switch is used as data is sent only to recipient
35
what are disadvantages to a star network
* Can be expensive to set up because of the length of the cable * Central device is point of failure
36
what is a physical topology of a network
it defines how the devices are physically connected to one another
37
what is a logical topology
it defines how the devices communicate across the physical topologies
38
what is a server
it is a powerful computer which provides services or resources required by any of the clients
39
what is a client
it is a computer which requests the services or resources provided by the server
40
what is the role of the client
* the client sends requests to the server * waits for a reply * receives the reply
41
what is the role of the server
* The server waits for requests from the clients | * it may need to pass the request to another server in which case It becomes the client
42
what are features of a client-server network
* central server is used to manage security * some files are held on the central server * some processing tasks are performed by the server * can require specialist IT staff to administer the network
43
give examples of types of servers
* web server * print server * Mail server * File server * Database server
44
what is peer to peer networking?
when each node on a server is able to send requests and process them.
45
what are features of a peer to peer network?
* suitable for small companies * cheaper as it doesnt require hardware * all computers can easily share/see files on all other computers * if a computer is switched off, data cannot be retrieved
46
what can peer to peer on a WAN be used for?
* the P2P configuration can be used for file sharing websites * P2P networks are used for illegal distribution of material.
47
what is cloud computing?
internet computing using remote servers run by organisations
48
Advantages of cloud computing?
* some software doesnt have to be downloaded to the users computer. * software and data is accessible from any computer anywhere in the world *  the data is automatically backed up so there is no danger losing it
49
define wi-fi
it is a wireless networking technology providing high-speed internet and network connections
50
How do devices connect to the internet
via a WAP
51
what is needed to connect to a wireless network
* ISP * Modem and wireless router * Device with NIC
52
what makes up wireless networking?
* wireless NIC * station consists of a computer and a NIC * stations share a radio frequency channel * WAP requires a connection to a router, and the router requires a connection to a modem
53
What is an SSID
service set identifier ; identifies each network by a locally unique name
54
what are features of an SSID?
* can be set manually or automatically * can be hidden to make it hard to detect * must be used by all devices on that network
55
what are disadvantages to wireless networks
* wireless networks are less secure; prone to man in the middle attacks, packet interception, cookie stealing * unauthorised users can be hard to spot
56
What are security measures used by wireless networks
* WPA * WPA2 * MAC address whitelist
57
what is the CSMA (Carrier Sense Multiple Access) algorithm ?
58
what are the consequences of using CSMA
collisions are avoided by each station transmitting only when the channel is idle
59
what happens when you use CSMA/CA with RTS/CTS

Computer Science (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions