Internet Structure ( 2 ) Flashcards
What is the worlds largest WAN?
The internet, it is composed of billions of of LANs
What is a standalone?
A computer not connected to any other computing device
How is a network formed?
When two or more computers are connected
What are the two types of network?
- LAN
* WAN
What is a wide area network?
- A network which relies on third party carriers, or connections provided by a telecom company.
- Spread over a large geographical area
What is a local area network?
- two or more computers connected together in a single site/small geographical area connected together by cables
- Network can consist of a number of computers, and shared resources such as printers and scanners and a central server.
What are some features of a LAN?
- Users on a LAN can communicate with each other
* Users on the network can share resources such as printers and also share data.
What is a network topology?
Arrangement of computing devices which make up a computer network.
What is a bus toplogy?
- Arrangement where nodes are connected in a daisy chain by a single central communications channel
- All computers are connected to a single cable
- Ends of cables are plugged into terminators
What are some advantages to a bus topology?
- Cheap to install, as it requires less cable than a star and does not require additional hardware
- Devices can be easily added
- Better for small networks
What are some disadvantages of a bus topology?
- If main cable fails, network data can no longer be transmitted to any of the computers/nodes, point of failure
- Performances degradation with high levels of traffic, due to data collisions
- Low security, due to all computers on the network being able to see all data transmissions
How does a bus topology work?
- All nodes are connected to a single backbone cable
- Backbones are connected to a terminator on either side ( to prevent signals bouncing back )
- Each node is passive
- Data is sent in one direction at a time only
- Only one computer can transmit successfully at any one time
What is the direction of data travel in a bus topology?
- Data is sent in one direction at a time only
* Only one computer can transmit successfully at any one time
What is the purpose of terminators?
Prevent signals bouncing back
What is a star network?
Arrangement where a central node/hub provides a common connection point,acts as a router to transmit messages.
What does a switch do?
Keeps a record of unique MAC addresses of each device on the network and can identify which computer on the network it needs to send the data to
What are the advantages of using a star network?
- If one cable fails, only one station is affected, easier to isolate problems
- Performance does not degrade with high levels of traffic, performance remains consistent whilst under heavy loads
- Higher transmission speeds, provides good performance
- No problems with collisions of data since each station has its own cable to the server
- System is more secure, since messages are only sent to where they are needed, directly to the central computer and are not able to be intercepted
What are the disadvantages of a star network?
- Expensive to set up due to length/amount of cable required
- If central device goes down, network data cannot be transmitted to any of the nodes, since central device is point of failure
What is the physical topology of a network?
The actual design, and how devices are physically connected
What is the logical topology?
- How devices communicate across the physical topology
* Shape of the path the data travels in, and describes how components communicate across the topology.
What is WI-FI?
Wi-fi is a local area wireless technology that allows you to connect to other devices via a wireless network access point ( WAP )
What does a station comprise of?
Computer + NIC
What is a NIC?
Wireless network interface card
What does a WAP require to function?
A connection to a router and the router requires a connection to a modem
