paper 1 - 1.3, 1.4 & 1.6 Flashcards
What are five advantages of networking computers?
- It is easy to share documents. Different users can work on the same document at once.
- Only one internet connection is required as it can be shared between every device connected to the network.
- Centralised backups can be carried out automatically.
- Software updates/patches can be automatically pushed out by the server to ensure that all devices are up to date.
- Users can log in to any machine connected to the LAN as accounts are stored centrally on the server.
What is the definition of ‘bandwidth’?
Bandwidth is the amount of data that can be transmitted in a given period of time
What does the acronym Mbps stand for?
Megabits Per Second.
Write about the impact that bandwidth can have on the performance of a network.
The amount of available bandwidth has a major impact on the performance of a network. The larger the amount of available bandwidth that is available the more data that can be transmitted in a given period of time.
If there is a large number of users on the network the amount of bandwidth available to each user may be limited. This will result in data being transmitted at a slower rate which will slow down the performance of the network.
Where large media files are being streamed the amount of available bandwidth is particularly important. Should a number of users be watching streaming HD content demand on bandwidth will be high. If there is insufficient bandwidth this could result in a reduction of quality in the video.
What is meant by the term ‘client server network’?
All devices are connected to a central server.
The central server receives and processes requests from ‘clients’.
The server stores user account details and files.
What are three reasons why you might choose a peer network model for a business?
All devices have equal status, there is no central server which makes them relatively easy to maintain.
There is no dependence on the server. If one device fails only the information stored on that device will be inaccessible. The network will still operate without that node.
They are relatively easy to set up without the need for a network manager.
A home internet connection goes through a hybrid device. What three network devices does it typically contain?
Router
Switch
Wireless access point
What is the purpose of a router?
To transmit data between at least two different networks
What does DNS stand for?
Domain Name System.
when you type a web address into a browser, what are the main steps that take place during this process to get the page to load?
- Enter URL into browser
- Browser requests IP address of site from ISP
- ISP requests IP address from DNS server
- DNS responds with details of the name server
- ISP asks name server for site IP address
- Name server responds with IP address of the host
- ISP sends IP address to the browser
- Browser sends request to the server hosting the site
- server hosting the site sends across content
- browser receives website content
- website displayed to the user
Many fast broadband connections use fibre optic cable instead of copper. What are three reasons why fibre optic cable is the preferred choice?
Fibre optic cables transmit data through light so do not suffer from electrical interference.
Data can be transmitted over very large distances without any loss of signal quality.
They are able to transmit data at a higher bandwidth.
Why is using cloud computing useful to some businesses?
[] Any user within the business will be able to load up the files on any device in any location as long as they have a data connection and the necessary permission.
[] If they runs out of storage capacity it is easy to increase.
[] All of the hardware and maintenance tasks will be performed by the cloud provider, they will not have a pay for specialist staff.
[] The data will be automatically backed up.
[] There is no large upfront cost. They will just have to pay a regular fee for the cloud services.
What is the role of a web server?
Control access to a centralised resource (definition of a server)
Stores content for web pages
Stores layout data for web pages
Receives and processes requests for web pages
What is the role of a web client?
Sends requests for web pages
Sends DNS requests for IP addresses
Displays the results of web requests
You have a games console in your bedroom and a video streaming device in your lounge. You use both devices to watch movies. The Wireless Access Point is located in the lounge. You have found that you are able to stream movies at a far higher quality in the lounge than in your bedroom. Why is this?
The further the device is from the WAP the weaker the signal will be, so the lower the bandwidth will be.
Objects such as walls and doors will reduce the signal strength.
Other electrical devices could reduce the signal strength and interfere with the signal.
When clicking a hyperlink to a webpage, which device is the server, which device is the client and what communication happens between them?
The webserver is the device that stores the webpage data.
The client is the computer that requested the web page.
When clicking a hyperlink, the client sends a request to the webserver.
The webserver processes the request and prepares the webpage.
The webpage is then sent to the client.
The webpage is opened in the client’s browser.
What are five reasons a Star network topology may be used to set up a new network?
They are very reliable.
If one connection fails it does not affect the rest of the network.
It is relatively easy to add additional devices onto the network.
It is relatively fast as each device has its own connection to the switch / server.
There are few data collisions.
What are five disadvantages of using a Star network topology instead of a Mesh network topology?
There is a high level of dependence on one single, central device.
If the central device fails the whole network will fail.
The use of a switch or router could increase the cost of the whole network.
The performance of the network will be dependent upon the specification of the central device/switch.
The number of additional devices that can be added to the network could be restricted by the central device/switch.
What is the definition of ‘protocol’?
A set of rules that govern how devices communicate.
What is the protocol that is used to transmit data between different networks?
Transmission Control Protocol / Internet Protocol. TCP/IP
What is the difference between HTTP and HTTPS?
HTTP transmits data over the internet in an unsecure format whereas HTTPS uses encryption so that any data that is intercepted is meaningless.
Data is transmitted across a network in packets. What are five items that each data packet will contain?
Network address source Network address destination Packet number / sequence Error detection codes Payload
what is IMAP used for?
it’s used to retrieve emails
what is SMTP used for?
it’s used to send emails
what is HTTP used for?
it’s used by web browsers to communicate with web servers
Protocols are divided into layers. Why are layers used?
Network communication components are standardised which helps to ensure that different types of hardware and software are able to communicate.
Through separating the overall network communication processes it makes troubleshooting easier should an error occur.
To ensure that if changes are made in one layer they do not affect any other layers
Through dividing overall network communication into smaller, individual components it makes the software development process more straightforward.
Packet switching is used to send data on the internet. How does packet switching work?
Data is split into individual packets.
Each packet is given a packet number which shows the numerical order of the packet.
The router reads the packet and sends it on to the next location.
The receiving device will read the packet number and reassemble the data in the correct order.
As the device reassembles the data from the packets if a packet is missing it will send an error message to the sending device requesting that the packet is resent.
The sending device will resend the packet.
Once all of the packets are received and reassembled the receiving device will calculate the checksum to ensure that none of the data has become corrupted.
A confirmation message will send from the receiving device to the sending device.