Networks Flashcards
Features of the Duck Campers’ van embedded parking camera system which prove its an embedded system
• it says customers which shows people can interact with the system
• it says embedded which shows its a computer within a larger mechanical system
• they are task specific because the camera system is built to show the driver how to drive
• the parking system has a reaction and real time which allow system to pick up on changes in the environment for e.g when the vehicle is too close to the pavement when parking
What is bluetooth?
A standard and a wireless technology which uses a radio frequency to share data over a short distance
What is wi-fi?
A medium range wireless technology used to connect devices together. Wi-fi used radio waves to provide a conn to the internet. The radio waves are transmitted by the WAP.
What are examples of 2 different bands of wifi?
2.4 Ghz • ultra high frequency
5 Ghz • super high frequency (1300 Mbps)
What are pros of wi-fi?
• allows u to set up LANs wirelessly
• enabled devices are now widely available
• users can log in from anywhere within the network using any wi-fi device
What are the cons of wi-fi?
• signal strength weakens the further u are from the router
• the wireless connection may not be as secure as a wired connection (interference and distance)
• wi-fi signal can be affected by weather
What are pro of bluetooth?
• low cost to set up
• uses relatively little power compared to other wireless connections
• u can easily set up bluetooth with other bluetooth enabled devices
What are cons of bluetooth?
• short range
• low level of security
• low data transmission rate
How does fibre optic cables work?
• uses light and consists of glass or plastic wires bundled together . Light is transmitted in pulses representing many frequencies.
• the transmitter in router sends light pulses representing binary code
• when data is recieved its decoded back to its binary form
Pros of optical fibre?
• supports many data transmissions e.g broadband
• minimal signal loss over distance
• signal difficult to intercept except if u were to destroy it
Cons of optical fibre?
• much more caro to install than copper cable
• requires more protection around the cable
The difference between the internet and world wide web
• internet is a global network of networks the name for the infrastructure and hardware
• www is a collection of files held on web servers that are connected by hypertext
What is the internet of things?
Connects smart devices over the internet and enables them to collect and exchange data
Whats an intranet?
A local or private network accessible only to selected individuals. A private network created using wide web software and protocols
How do LANS and WANS connect?
LANS connect via ethernet or wi-fi.
Internet is an example of a WAN. A WAN is a collection of connected LANS.
Compare client server to peer to peer models
Client server is when a computer relies on other computers to provide and manage data and has no control over the network.
A peer to peer model is when all comps have the same status.
They are able to share files and have more accessibility.
Peer to peer is best for smaller organisations
Client is best for larger organisations
What are 3 things that the data protection act makes illegal?
•unlawful obtaining or disclosing of personal data
• re- identification of personal data
• altering personal data
What are 3 best file storage solutions for teaching?
• solid state drive could be used for bigger software because it has quite a lot of storage and fast access speeds such as USB drives which are portable and reliable storing presentations
• magnetic storage such as hard disk drive could store any virtual cloud apps
• optical devices such as.CDs, DVD’s storing videos for teaching
Whats the link layer?
How neighbouring nodes on a network communicate
Whats the internet layer?
Transfer data between networks
Whats the 3 mail protocols?
IMAP, SMTP, POP
What does SMTP do?
Simple mail transfer protocol which sends emails over the internet
Features of the POP protocol?
Once the email has been received the email is deleted from the server
Works best with one device
Stored locally
Your emails are downloaded and stored on the computer you use
Features of the IMAP?
• works well with multiple devices
• more modern
• emails can be accessed locally and is not deleted from the server
• your devices synchronise with server
What is layering?
A division of network functionality which allows certain parts of a protocol to be worked on without affecting the other layers. Part of a protocol which perform a specific task
Pros of cloud computing?
• reduced software costs
• more storage
• lots of accessibility
What is the application layer?
Encodes the data being sent so that it will be understandable by the recipient
Whats a network policy?
A set of rules which users of the network must adhere to
What is the FTP?
A standard protocol used when transferring comp files between a client and the server on a comp network
Whats a network standard?
Specifies the way that computers across a network, the speeds used or different types of network are used
Why do different ISP’s use different broadband speeds?
• the network can experience bandwidth issues and latency issues such as the the time delay of the transmission of the first data packet
• interference during transmission from other devices that emit electromagnetic signals which can cause dropped connections. Resulting in weaker connection
Explain why network performances deteriorates as number of uses increases
•available bandwidth used up
• lots of data collisions can occur
• also interference
What are errors in transmission?
Due to noise or distortion this means data has to be retransmitted
What is the packet switchin diagram?
• IP address (destination of recipient)
• no. Of packets in whole communication
• error check sum
• no. Of sequence packets
Whats circuit switching?
When you make a telephone call, a dedicated connection is set up between you and the person you are calling for the duration of the call.
Whats the purpose of the NIC?
Helps to connect devices to the network
Whats a computer network?
2 or more nodes connected together to share information and resources
What are examples of data transfer media?
Ethernet and wi-fi
Difference between switch and hub
Hub forwards data to all nodes on a network (unintelligent)
Switch forwards data to intended recipient (intelligent device)
Why might data transfers be slow?
Data collision
Shared processor power
What is cloud computing?
Devices connected through the web
What are 2 pros and cons of LANS?
Pros = fast and easy, sharing resources
Cons = only spans over small area, requires a lot of maintenance
Pros and cons of client server
Pros = data security, easy management, accessibility
Cons = high cost, identification is shown, network traffic congestion
What are pros and cons of peer 2 peer?
Pros: reduced cost, more availability of resources, enhanced privacy and anonymity of nodes
Cons: security concerns, perfomance limitations, no central maintenance ,
Pros and cons of cloud?
Pros = • access data anywhere with an internet connection
• you can share the data with people in different locations
• more accessibility to softwares
Cons= susceptible to hackers, dependent on internet connection
Who is the ISP?
The company who provides you with an internet connection
What is a virtual network?
One which uses software to subdivide a physical network.
How DNS works
- Computers can only connect to other comps if they have their IP address
- We type in the URL
- The URL is sent to our ISP they look up the URL in their DNS book
- They find it and send back the websites address
- Now our computer can communicate with the website
