Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

OCR GCSE Computer Science > 1.3 Networks, protocols and layers > Flashcards

1.3 Networks, protocols and layers Flashcards

1
Q

Networks pros

A
  • share printers and devices
  • access files from any computer
  • easier communication - email and file sharing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Networks cons

A
  • Security risk for data
  • Easier for malicious software to infiltrate network
  • Switch is a central point of failure
  • More users means it is slower
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

LAN

A
  • Small geographical area
  • Hardware is owned by the company using it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

WAN

A
  • Large geographical area
  • Lot of LANs connected
  • Routers connect the LANs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Bandwidth

A
  • amount of data sent / recieved at any time
  • Bits/ second
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a network model

A
  • The logical structure of a network
  • Defines how the network works on top of the topology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Latency

A
  • Delay between when data is sent/ recieved
  • More delat means more data collissions in network
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Client

A

A client is a computer on the network, these connect to the server via a switch

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

Server purpose

A

Managing access to the Internet
Managing printing
Providing email services
Providing backups
Controlling security

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

Server properties

A

Servers are often more powerful than the client machines
Servers are seen as more significant than the client machines and can require specialist hardware and software
A network which uses a server is called a client-server model
Most companies, organisations and schools will use a client-server network model

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

Client server model pros

A

Managing backups of the network is easier as it is done from one central point

Updating and installing new software can be done centrally instead of having to log on to each machine

Security of files can be managed easily

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

Client server models cons

A

Servers can be expensive to purchase, setup and maintain

A specialist network manager would be required as servers require specialist IT knowledge

Servers can be a single point of failure, meaning all users would lose access to the network if the server fails

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

Peer - peer network

A

A peer is a computer on a network which is equal to all other computers

Each peer on the network

  • Often have their own printer attached
  • Will provide access to their own files
  • Is responsible for their own backups
  • Is responsible for their own security
  • Is responsible for carrying out their own backups

A network with no server providing services is a peer-to-peer network

Most homes will have a peer-to-peer network model

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

Peer - peer pros

A

Very easy to set up and maintain

Very cheap to set up because there is no expensive hardware to purchase

No specialist knowledge or staff are required to run the network

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

Peer - peer cons

A

Users will need to manage their own software updates
Users will need to manage their own backups

The network can be less secure

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

WAP

A

Wireless access point
Allows wireless connection to a LAN
Connects to a switch/ hub via ethernet

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

Router

A

Transmits data packets accross networks
Connects LANs to the internet
Uses IP address

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

Switch

A

Connects wired devices to a LAN
Uses the MAC address
Recieves data from all devices in a network
Directs data to the correct destination

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

Router vs switch comparison

A

Same:
* Connect devices
* Recieve data
* Determine correct destination
* Transmit data

Different
* Router uses IP, Switch uses MAC
* Switch connects nodes, Router connects networks
* Router stores IP addresses of devices

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

NIC

A

Network interface card
Required to allow computer to connect to a network
A NIC can be both wired and wireless and allows your computer to send and receive data over a network

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

What happens when you enter a URL

A

URL Entry: The user enters the URL (web address) of a website into the web browser

DNS Query: The web browser sends a query to a DNS server to translate the URL into an IP address

DNS Resolver: The DNS resolver checks its cache to see if it has the IP address for the requested domain. If not, it sends the request to the DNS root servers

Root Server Query: The root server directs the resolver to a Top-Level Domain (TLD) server

TLD Server Query: The TLD server then provides the resolver with the IP address of the domain’s authoritative DNS server

Retrieve IP Address: DNS server responds with the IP address for the requested domain

Request the Web Page: The web browser sends an HTTP or HTTPS request to the IP address it received

Server Response: The server at the given IP address processes the request and sends back the data for the web page (HTML, CSS, JavaScript, etc.)

Render the Web Page: The web browser renders the received data into the web page that you see

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

Web servers

A

Web servers are dedicated servers that store web pages/websites and other resources

They have a dedicated IP address to ensure that users can access them 24/7

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

Clients

A

Clients are end-users who make requests of web servers

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

What is hosting

A

Hosting is the storing of websites, files and other content on servers

The servers need to be accessible by potentially thousands of users and they need to be available 24/7

The servers must be reliable and secure from any form of attack

The IP address for the server must remain the same so that users can access the website whenever they want

Servers are set up with the single purpose of serving these files in this manner and in a safe and secure way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the cloud
The cloud is a collection of servers which are used to store data, applications and files over the internet
26
Cloud pros
Content in the cloud can be accessed anytime and from anywhere Users can use any device to access their content Users have a large storage capacity available to them Low cost / free to set up and use Responsibility for backups and security is with the cloud service provider Users can easily collaborate
27
Cloud cons
Accessing content and software is only possible when the user has an internet connection Expanding capacity can become expensive if using it across a business Vulnerable to security threats such as data leaks and photo leaks It is not thoroughly clear to users who is the owner of the data once it is uploaded to a cloud service
28
Mesh pros (and an example of mesh)
* No single point of failure * Expansion/ modification doesn't disrupt the network * Data transmitted from different devices simultaneously Used in the internet / IoT
29
Mesh cons
* Possible redundant connections * Cabling is expensive * Maintenence/ admin is diffucult
30
Star pros
* Network functions if only 1 cable breaks * Data is not transmitted to every node - fast
31
Star cons
* Switch can be a central point of failure * Need to buy a switch - expensive
32
Wireless mesh pros
Only 1 node needs wired connection More nodes = more data routes
33
Bluetooth
Connects 2 devices Pros: * Compatable * Low power Cons: * Slow * Unsecure * Small range
34
Wi-Fi
Common standard for wireless transmission Pros: * Portable * Lower cost as no wires needed * More compatable as it is built in Cons: * Slower * Less secure * Limited range * Need WAP
35
Ethernet
Pros: * Fast * Secure * Not susceptible to interference * High bandwidth * Reliable Cons: * Portability * Cable cost * Trip hazard
36
2.4 GHz
Pros: * Further range * Can penetrate solids Cons: * Lots of interference * Slower
37
5GHz
Pros: * High transfer speed * Less interference Cons: * Shorter range * Can't penetrate solids
38
How is wireless data encrypted
Wireless networks are identified by a 'Service Set Identifier' (SSID) which along with a password is used to create a 'master key' When devices connect to the same wireless network using the SSID and password they are given a copy of the master key The master key is used to encrypt data into 'cipher text', before being transmitted The receiver uses the same master key to decrypt the cipher text back to 'plain text' To guarantee the security of data, the master key is never transmitted. Without it, any intercepted data is rendered useless
39
What is IP
Unique identifier given to devices to communicate over the internet (WAN) Dynamic Allows us to control where data goes
40
IPV6
8 blocks of 4 hex digits. Separated by colons. Each block is 2 bytes so in total it is 16 bytes. e.g 1111:21F6:1123:7EEE:82F7:2222:912A:2112
41
IPV4
4 Blocks of denary 0-255 separated by a dot. Each block is 1 byte which means the full thing is 4 bytes. 4 billion combinations. e.g 1.10.100.200
42
What are MAC addresses
Unique identifier for LAN Static Used by switches to send data to intended recipient Assigned to NIC
43
MAC address example
6 groups of 2 Hex digits. 6 bytes. First half is the manufacturer ID. The last half is the serial number. e.g. 00-0A-1B-2C-3D-4F
44
What are network standards
A computing standard is a set of guidelines that when used with different hardware and software allows them to work with each other (compatibility) and allow data exchange (interoperability) Standards give manufacturers and software developers the ability to create hardware and software that will function together
45
HTML
A standard for creating websites that allows them to be viewed on the World Wide Web (WWW) using web browser software
46
Ethernet
A standard for wired network cables that allows the network to function
47
USB
A standard that defines the physical connector used for connecting peripheral devices to computers
48
What are protocols
A protocol is a set of rules that govern communication on a network
49
TCP/ IP
TCP/IP is two protocols, transmission control protocol (TCP) and internet protocol (IP) that combined allow communication over the internet (WAN) TCP is responsible for making sure communication between two routers is error free IP is responsible for making sure data is delivered to the right device on a wide area network (WAN)
50
HTTP/ HTTPS
Hypertext Transfer Protocol (HTTP) allows communication between clients and servers for website viewing HTTP allows clients to receive data from the sever (fetching a webpage) and send data to the server (submitting a form, uploading a file) HTTPS works in the same way as HTTP but with an added layer of security. All data sent and received using HTTPS is encrypted HTTPS is used to protect sensitive information such as passwords, financial information and personal data
51
FTP
File Transfer Protocol (FTP) allows sending and receiving files between computers Uploading and downloading files to/from a web server is often completed using FTP FTP offers greater efficiency and support for bulk transfers and large files such as resuming interrupted transfers FTP clients are software applications that use the FTP protocol to make the process easier for users
52
SMTP
Simple Mail Transfer Protocol (SMTP) is a protocol that allows communication between an email sender and the email server, and between different email servers using the internet
53
POP
Post Office Protocol (POP) is a protocol for downloading emails to a device from an email server Once the email has been retrieved it is removed from the server
54
IMAP
Internet Message Access Protocol (IMAP) is a protocol for downloading emails to a device from an email server Once the email has been retrieved, a copy is retained on the mail server
55
POP pros/ cons
Pros: * Frees up storage space on email servers * Faster on slow connections Cons: * Only access emails from the device they're downloaded to * Emails deleted on the server once downloaded
56
IMAP pros/ cons
Pros: * View and manage emails from any device with internet access * Changes made on one device are synchronised on all connected devices Cons: * Server storage space can limit amount of retained emails * Requires internet access to view emails
57
Order of network layers
Application Transport Internet Link
58
Application layer
Browser - sends file to transport layer HTTP, FTP, SMTP, DNS
59
Transport layer
Breaks down information from application layer into packets - sent to internet layer TCP
60
Internet layer
deals with IP addresses and routes packets to its destination IP
61
Link Layer
deal with hardware such as NICs and cables Ethernet, Wi-Fi
62
Advantages of layers
- Layers are self-contained / independent - The functionality of one layer can be changed without affecting the functionality of other layers - Different hardware or software operates on a particular layer providing interoperability between providers and systems - A developer can specialise on a particular layer
63
What are network layers
Stages in the transport of data across a network Example of decomposition

OCR GCSE Computer Science (12 decks)

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