1.5 Network Topologies, Protocols and Layers Flashcards
Define topology
The technology behind the connected devices.
What is a mesh network?
Full – All devices are connected to each other.
Partial – Not all devices are connected to each other.
What are the advantages of a mesh network?
1) No single point where the network can fail:
If the node in the route fails, the packet is sent a different way.
2) Can handle high volumes of traffic (why it’s faster).
3) Adding more nodes won’t hinder the process as all nodes help to transmit data.
What are the disadvantages of a mesh network?
1) Expensive to set up - needs a lot of cables.
2) Hard to manage.
What is a star network?
Each device is connected by an individual cable directly to the server.
What are the advantages of a star network?
1) If a device fails, the rest of the network is unaffected.
2) Simple to add new devices.
3) Good performance.
4) Fewer data collisions.
5) Easier to manage from a central point.
What are the disadvantages of a star network?
1) Switch depends on the network (switch dies = network dies).
2) Can be expensive for cables.
Define encryption
A method of scrambling data with a key code which makes no sense.
Why is encryption used?
So if anyone intercepts other people’s packets, they would make no sense (the key is need to decrypt the packets).
What is packet switching?
Process of breaking down data and sending it in smaller “packets” then reassembling the data at the receiving end.
What are the contents of the packets?
1) IP of origin location.
2) IP of destination.
3) Order (of packets).
4) Check Sum (checks correct number of packets have been).
Which route do the packets take?
The fastest route; not the shortest (often differs for each packet).
What does the sending device do?
Splits data into equal sized packets which will be given:
- A number
- The IP address of the receiver’s device
- Error checking data.
The packets are sent across the network to the receiver’s device.
What does the receiving device do?
1) Checks if all the packets have been received.
If they’re not received, it keeps checking.
2) Increments a timer and if the packets aren’t received in time, it sends timeout to the sender’s device.
3) If they are received, they order the packets numerically and display the sent thing.
What is an IP address?
A unique string of numbers separated by full stops that identifies each computer using the internet protocol to communicate over a network.
