Networks Flashcards
What are the differences between a WAN and a LAN
Wide-area network: Located geographically distanced across a country or even the world.
Local-area network: Located geographically closer together, in the same building or small site.
Give an example of how WAN and LAN can be used
LAN: servers and routers managed by a network owner
WAN: Third party communication channels by internet services (BT or virgin media)
How does a peer-to-peer network function
Data is shared directly between systems without a central server.
How does a client-server network function
Clients make requests to a server as it is dependent for providing and managing information. The server controls security, backups and updates
Give one use of a client-server network
Large companies such as amazon will manage requests clients make and will need powerful servers.
What are the advantages and disadvantages to star topology
- Improves security
- Transfer speed is fast
- Extra hardware required
- Central system fails, so does the rest
What are the advantages and disadvantages to mesh topology
- Data can take alternative route
- New systems can be added
- Large amount of cables
- Cables connected to systems that will never communicate
List 5 factors that affect the performance of a network
Bandwidth, number of users on at the same time, amount of data being transferred, number of data collisions, interference and signal strength
How does a switch work
It connects devices together on a LAN, where it receives data packets from a connected node, reads the destination address in the packet header and forwards the data directly to its destination
Describe the purpose of a router
Transfers data packets between networks by using the IP address in the packet header to determine the best route to transmit data - router to router
State WAP and why it is used
A wireless access point provides a link between wireless and wired networks (wifi or bluetooth hotspot in public areas)
State NIC and why it is required
A network interface card is an internal piece of hardware that is required for the computer to connect to a network.
What are the differences between 3 transmission medias
Ethernet: Transfers data between nodes and hardware such as switches (in a LAN)
FibreOptic: Expensive, fast cables used to transfer data quickly across a WAN
Coaxial: Older, slower which are affected by electromagnetic interface
State what the internet is and how it’s difference to the World wide web
A global network of interconnected networks, and is different as it is a way of accessing information using protocols such as HTTPS to view web pages
What is web hosting
A website stored on a web server so then it can be accessed by others using the internet
What is a DNS server
Domain name system stores a list of domain names and a list of corresponding IP addresses where the website is stored (as it is easier for humans to remember and type)
How is a DNS used to display a webpage
- A domain name is typed into the address bar
- A query is sent to local DNS for corresponding IP address
- DNS will check if it corresponds and will pass it to the browser
How does the DNS find an IP address if it isn’t found in the Local DNS server
The query is passed to another DNS server at a higher level
What is Cloud computing
Networks of servers accessed by the internet, with the purpose of running applications, remote processing and storing data
What are the advantages and disadvantages of cloud
- Huge capacity
- Very portable
- Access can be dependent on connection
Which has more freedom? Wired or Wireless
Wireless
Which is faster? Wired or wireless
Wired
Which is more secure? Wired or wireless
Wired
What does Wired and Wireless require
Wired: NIC
Wireless: WNIC
What is a protocol
A set of rules that allow devices to communicate with each other
List the 8 protocols
TCP, IP, HTTP & HTTPS, FTP, SMTP, POP3 and IMAP
Describe TCP (Transmission Control Protocol)
Allows data packets to be sent and received between computer systems which breaks them down and reassembles them back together
Describe IP (Internet Protocol)
Routing and addressing data packets to ensure they are sent to the right destination, using an addressing system where every device on a network is given an unique IP address
Describe HTTP/HTTPS (Hypertext Transfer Protocol)
Used to transfer web pages over the internet so that users can view them in a web browser. HTTPS is a more secure version to transfer encrypted data
Describe FTP (File Transfer Protocol)
Transfers files across a network, commonly used to upload or download files
Describe SMTP (Simple Mail Transfer Protocol)
Sends emails to a mail server and between mail servers
Describe POP and IMAP (Post Office Protocol & Internet Message Access Protocol)
Both protocols used for receiving and storing emails from a mail server. POP deletes an email after downloaded and IMAP syncs message to a mail server
What are the network standards
Rules that a computer that allows a computer to communicate across networks. Standards have been created to ensure devices can exchange data and work together
Why are network designs split into layers
Helps visualise different parts of a network as it is simpler and easier to modify
This layer ensures data packets are sent and received correctly:
Transport
This layer checks for errors in transmission and sets out the data packet format:
Data Link
This layer allows software like web browsers to interact with the network:
Application
This layer uses address to ensure it takes the correct route:
Network
