1.3: COMPUTER NETWORKS, CONNECTIONS AND PROTOCOLS 2.0 Flashcards
what are the 2 common models for connecting computers over a network?
client-server networks
peer-to-peer networks
what is a client?
a computer that relies on other computers (servers) to provide and manage data
why are clients in a client-server network limited? (2)
- do not usually store data
- they have no control over the network as a whole or over individual computers.
what are client-server network best suited for? (2)
- organisations with many computers
- situations where many computers need access to the same information.
what are P2P network best suited to? (2)
- smaller organisations that have fewer computers
- situations where fewer computers need access to the same data.
what do all computers in a P2P network have? and what does this mean?
equal status
- no computer has control over the network.
what is each computer known as in a P2P?
peer
Describe the relationship between a client and a Web Server. (4)
- A web server holds the data needed for the website (both the content of the website and the layout).
- When someone wants to view a web page their web browser sends a request to the web server.
- web server processes request and prepares the data that has been requested, before sending it back.
- The web browser then receives that data and displays the web page to the viewer.
what are devices in a network connected by?
a wired/ wireless medium
what is a computer or device that is not connected to a network is called?
a stand-alone
which hardware components are required to connect a computer to a network? (3)
- a network interface controller/card (NIC) or wireless network interface controller
- a transmission medium (either wired or wireless)
- a point to connect to, such as a router, hub, switch or wireless access point
what do most modern devices have? why?
a NIC and a wireless NIC built in
-providing the option of either connection method.
what do transmission medias do? what are they either?
carry data signals from one computer to another
-wired or wireless
which wired transmission medias are used in modern networks? (2)
- twisted copper wiring (ethernet)
- fibre-optic cable.
characteristics of twisted copper wire and fibre-optic cable: (6)
in terms of:
- cost:
- maximum transmission speed:
- maximum distance for reliable communication:
cost:
TCW: Cheap
FO: Expensive
maximum transmission speed:
TCW: much slower
FO: extremely fast
maximum distance for reliable communication:
TCW: Up to 100 metres
FO: Over 2 kilometres
advantages and disadvantages of wired networks: (2)
ADVANTAGES:
-reliable as not usually subject to interference.
DISADVANTAGES:
-limited mobility - as wired device has to stay in place.
advantages and disadvantages of wireless networks: (3)
ADVANTAGES:
-ideal for mobile devices as a device can connect to a network as long as it is in the range of a wireless access point.
DISADVANTAGES:
- use radio waves to carry signals; these signals are limited in range (usually up to 50 metres),
- subject to magnetic interference - can also be blocked by walls.
what can WAPs also be used for? and how? (2)
- can be used to extend range of a wireless network.
- WAP can either receive and transmit traffic to other WAPs, or be connected via a cable to the main network.
3 advantages of using the cloud:
- ability to access files from any location or any device, so long as an internet connection exists
- access can be granted to another user so they can remotely access your data
- reduced need to make backups - cloud storage services back up the data for you
3 disadvantages of using the cloud:
- there is no guarantee that someone else is not accessing your data
- Security – Data stored online is vulnerable to security attacks.
- access to data is only possible with an internet connection - no connection means no access to data
what is network performance in reference to? give an example
response time
-how fast a message can be sent or how quickly a document can be retrieved
what would a website that is hosting need to do?
would need to have registered domain name with a domain registrar
what can hosting do? what will it be placed it?
enable other people see your web site, which will be placed on a web server.
why does a website that is hosting need to have registered with a domain name register?
they would ensure that the domain name is unique and not already registered
advantages of a star topology: (2)
If one computer on the network fails, the rest of the network continues to function normally.
Centralised management of the network, through the use of the central computer, hub, or switch.
disadvantages of a star topology: (2)
High level of dependence on one single, central device.
Expensive (Network hardware eg switches + Technician).
advantages of a mesh topology: (2)
A failure of one device does not cause a break in the network or transmission of data.
Manages high amounts of traffic, because multiple devices can transmit data simultaneously.
disadvantages of a mesh topology: (2)
Impractical to set up because of the high number of connections needed.
Many connections require a lot of maintenance.
what is the cloud?
Remote servers that are used to store data and run applicaitons that are accessible via the internet
why would websites need to have registered domain name with a domain registrar?
they would ensure that the domain name is unique and not already registered
