Learning Aim B Flashcards
What is Ethernet?
Technology which uses a physical cable to speedily transmit data from a device into a LAN. It is the standard technology for connecting to LANs and uses protocols or a set of rules to transmit data.
What is a fibre optic cable?
A cable made of glass that becomes flexible when it is thin. It causes digital info to travel faster than Coptic cables.
What do copper cables look like?
They come in the form of a twisted pair.
What are the advantages and disadvantages of copper cables?
+ excellent conductivity
+ good
durability
+ resistant to heat
-expensive
-heavy weight
-difficult to install
What are the advantages and disadvantages of fibre optic cables?
+ greater bandwidth
+ faster speeds
+ can cover longer distances
-fragile so is vulnerable to damage
- expensive to install and maintain
- difficult to repair when damaged
What is LAN (local area network)?
A collection of devices connected together in one physical location, such as a building, office, or home.
What is WAN (wide area network)?
A large computer network that connects groups of computers over large distances, typically used by businesses.
What is PAN (personal area network)?
A computer network for interconnecting electronic devices within an individual person’s workspace like a wireless mouse.
What is bandwidth?
The range of frequencies a transmission can carry.
What is broadband?
A high-speed connection to the internet.
What are the advantages to user needs
Sharing files-
once computers are networked, files can either be stored on the server, and any authorised person on the network can download them to their own computer.
Sharing resources -
printers, scanners, hard drives and other resources can all be shared. Sharing an Internet connection is one of the main reasons many networks are set up.
Centralised backup -
files saved on the server can be backed up on an automatic schedule, for example daily, onto tape or other removeable device. The backup copy will be kept offsite.
What are some decisions user needs will need to make
• what type of network to set up
• suitability of different connection types
• security measures
• compatibility with existing systems
what is peer to peer
A P2P network is a decentralized system where each device (peer) acts as both a client and a server. This means any peer can request or provide services (like file sharing or computing power) directly to other peers.
What is a client server
is a network architecture where a server provides resources, data, or services, and a client accesses these services by sending requests to the server. The server processes the requests and sends the required responses back to the client.
Advantages and disadvantages of client server
Advantages
1.Centralised Control: Easy to manage and secure resources in one place.
2.Scalability: Servers can be upgraded to handle more requests.
3.Efficiency: Servers specialize in processing and providing resources.
Disadvantages
1.Single Point of Failure: If the server goes down, clients cannot access services.
2.High Costs: Setting up and maintaining powerful servers can be expensive.
3.Limited Scalability: Overloaded servers may struggle to handle high demand.
Advantages and disadvantages to peer to peer server
Advantages
•Decentralised, reducing reliance on a single point of failure.
•Scalable as peers contribute resources.
Disadvantages
•Can be less secure if not properly managed.
•Difficult to maintain quality and consistency across all peers.
What is a leased line
A leased line is a private, high-speed internet connection that is always active and used only by one customer. It provides a reliable and dedicated link for businesses to connect to the internet or other offices.
Advantages and disadvantages to leaded lines
Advantages of a leased line
• It gives very fast upload and download speeds of up to 10 Gbps.
• It is not shared with anybody else, so speeds won’t fluctuate.
• With most leased lines, you can change your bandwidth whenever you want, meaning you pay less in
quiet periods.
• It is more secure than a shared line.
Disadvantages of a leased line
• It is a very expensive option.
• It can take up to three months to get a leased line installed, whereas regular business broadband can
normally be installed in about two weeks.
What is a VPN
A VPN (Virtual Private Network) is a service that creates a secure connection between your device and the internet. It encrypts your data to protect it from hackers and hides your IP address.
What are the issues with VPN
VPNs require a connection with high bandwidth for both uploads and downloads, and low latency (see to function efficiently. Satellite Internet services normally suffer high latencies due to the long distance satellite signals must travel, and satellite bandwidth for uploads is much slower than for downloads.
There are other compatibility issues which may prevent connection to a VPN. In some cases, a firewall may block the VPN when a user tries to connect to the VPN server. If the user is trying to connect to the VPN from home, their router may need a router firmware update to be compatible with the VPN.
What is a protocol
A protocol is a set of rules defining common methods of data communication. These rules need to be standard across all devices in order for them to communicate with each other. A protocol will specify, for example:
• the format of data packets
• the addressing system
• transmission speed
• error-checking procedures being used
What does an email protocol do
A mail server acts as a virtual post office for all incoming and outgoing emails. The server routes mail according to its database of local network users’ email addresses as it comes and goes, and stores it until it can be retrieved
what are the three main protocols used in an email protocol and what they each do
• Post Office Protocol (v3) (POP3) is responsible for retrieving emails from a mail server that temporarily stores your incoming mail. When emails are retrieved, they are transferred to your device , and deleted from the server.
• Internet Message Access Protocol (IMAP) is an email protocol that is designed to keep emails on the server, thus maintaining synchronicity between devices.
• Simple Mail Transfer Protocol (SMTP) is used to transfer outgoing emails from one server to another or from an email client to the server when sending an email.
What is VoIP
allows users to make free, or very low cost, telephone calls over the Internet. In a business using VolP, an employee can call any telephone in the world and anyone can call the VolP telephone regardless of what equipment or network the person uses.
what are the features and services VoIP include
• voicemails sent to your email
• call diverts
• call conferencing
what are the protocol in a web page protocol and what they each do
НТТР (HyperText Transfer Protocol) is the standard protocol for browsers to render web pages. It defines howmessages are formatted and transmitted, and what actions Web servers and browsers should take in response to
various commands. When you enter a URL (web page address) in your browser, this sends an HTTP command to
the Web server directing it to fetch and transmit the requested Web page.
TCP defines how applications can create channels
of communication across a network. It specifies how a message is assembled into smaller packets before being transmitted over the internet and reassembled in the right order at the destination address.
IP defines how to address and route each packet to make sure it reaches the right destination. Each gateway computer on the network checks this IP address to determine where to forward the message
HTTPS (secure protocol) encrypts the information so that it cannot be understood if it is hacked. Banks and many other organisations always use the https protocol. Data sent over a standard Internet connection is inherently insecure. Organisations needing to keep personal data secure may use a VPN, which provides a secure tunnel, with all data encrypted, between routers.
NFC (Near Field Communication) is a communication protocol set which can be used to transfer data between devices within a few centimetres of each other. This can be used for transferring photographs, mobile ticketing and in many places to make payments by tapping a smartphone on a credit card terminal (NFC receiver) to send
payment automatically.
What are the factors that affect latency
• Transmission medium:Fibre-optic cable wil transmit data much faster than coaxial cables
• Bandwidth
• Connection
• Internet traffic load at busy times of day
• Distance
What is Latency
Latency is the time delay between the moment that transmission of the first byte or packet of a communication starts, and when it is received at its destination. It is a function of the time it takes the information to travel from source to destination.
What is data compression
is the process of reducing the size of a file or data set so that it takes up less storage space or can be transmitted more efficiently. It is commonly used in computing to save bandwidth, improve transmission speeds, and optimize storage.
What are the two types of compression
1.Lossless Compression:
•No data is lost during compression.
•Example: ZIP files, PNG images.
2.Lossy Compression:
•Some data is removed to achieve greater compression, which may reduce quality.
•Example: MP3 audio, JPEG images.
what is lossy compression
is a method of reducing the size of a file by permanently removing some of its data. It achieves significant size reduction by removing less important information that may not be noticeable to the user
Advantages and disadvantages to lossy compression
Advantages
•Significantly reduces file size.
•Saves bandwidth for streaming and storage space.
•Suitable for applications where perfect quality isn’t necessary.
Disadvantages
•Loss of data and quality, which can be noticeable in extreme compression.
•Irreversible: Once data is removed, it cannot be restored to its original state.
•Not ideal for data where accuracy is critical (e.g., medical images, legal documents).
What is lossless compression and how does it work
Lossless compression works by recording patterns in data rather than the actual data. Using these patterns and a set of instructions on how to use them, the computer can reverse the procedure and reassemble an image, sound or text file with exact accuracy and no data is lost.
it is a method of reducing the size of a file without losing any data. The original file can be perfectly restored after decompression, making it ideal for applications where accuracy and quality are essential.
Advantages and disadvantages of lossless compression
Advantages
•Perfect data recovery.
•Maintains quality, which is crucial for critical applications like medical imaging, legal documents, or databases.
•Compatible with a wide range of data types.
Disadvantages
•Achieves less compression compared to lossy methods.
•Larger file sizes, which may increase storage and transmission costs.
What is codec
A codec (short for coder/decoder) is software used for converting analogue signals into digital form, or for converting between digital signal formats.
A codec may also compress the data to reduce transmission bandwidth or storage space. Compression may be lossy or lossless.
