1.3.1 Networks and Topologies Flashcards
How does Number of Users affect Network Performance?
Too many users can cause a network to slow down as bandwidth has to be shared among users.
- won’t always be shared equally.
How does Transmission Media affect Network Performance?
Cheaper cables (copper) cannot carry as much data or as quickly as more expensive ones (fibre optic). Wired have a higher bandwidth than wireless.
How does Error Rate affect Network Performance?
Less reliable/weaker connections have a higher error rate, which means data has to be resent again until send correctly.
How does Bandwidth affect Network Performance?
Low bandwidth means less data can be transferred at a given period of time.
How does Latency affect Network Performance?
Caused by bottlenecks in the infrastructure of the network.
- causes delays when transmitting and receiving data.
Advantages of a Wired Network.
- high bandwidth.
- excellent security as node has to be physically connected to the network.
- allows hundreds of people to log in at the same time
- immune to radio interference.
Disadvantages of a Wired Network.
- signal affected by walls & doors.
- more costly to install in a building.
- not portable.
- many physical cables needed.
Advantages of a Wireless Network.
- not affected by building layout.
- only needs a WAP to set up, so is cheaper.
- very mobile.
Disadvantages of a Wireless Network.
- lower bandwidth.
- not very secure.
- affected by radio interference.
- only allows a limited number of people to be connected at a given time.
Advantages of a Peer-to-Peer Model Network.
- not dependant on a single machine.
- easy to maintain as specialist staff aren’t required.
- cheaper to set up as no expensive hardware is required.
Disadvantages of a Peer-to-Peer Model Network.
- users need to manage their own backups.
- network is less secure.
- difficult to maintain a well-ordered file store.
Advantages of a Client-Server Model Network.
- easier to manage security of files.
- easier to take backups.
- easier to install software updates.
Disadvantages of a Client-Server Model Network.
- can be expensive to set up & maintain.
- requires IT specialists to maintain.
- users will lose access if the server fails.
What is a Wireless Access Point?
A device that connects wireless devices to a wired network.
- is able to pick up Wi-Fi data packets and convert them into data packets for the wired network & vice versa.
Disadvantages of a WAP.
- doesn’t read the MAC address of a data packet so it’s broadcasted to everyone.
- data packets may be read by another device connected to the same WAP.
What is a Router?
A device that transfers packets via the most efficient route between networks & connects other networks together.
- helps filter traffic & prevent unauthorised intrusion by malware
What happens when a Router receives a data packet?
- Reads the packets destination address
- Looks at all available paths to that address
- Checks how busy each path is
- Sends packets along the fastest route
What is a Switch?
A device that connects nodes within a LAN and directs data packets to their destination.
- reduces the impact of data collisions
- doesn’t broadcast every data packet to every device
What is a Network Interface Card?
Allows devices to physically connect to a network.
- holds the Media Access Control address (unique hardware address)
- responsible for converting data on the computer into the form used by the network
What are Ethernet cables?
- made of copper wires in a plastic sleeve
- data is carried by electrical signals
What are Fibre Optic cables?
- uses light signals to send data
- more expensive than Ethernet cables
- higher bandwidth
What is the Domain Name Server?
The Internet’s system for converting alphabetical names into IP addresses
- keeps index of URLs and IP addresses
Advantages of a DNS.
- can change to a new IP address if the host’s IP address changes
- easier to remember than an IP address
What is Hosting?
The storing of files and data on a web server
