Section 3: Networks Flashcards
What is a layer?
a division of network functionality that allows different aspects to be developed separately
What is the order of the 4 layers?
application layer
transport layer
internet layer
network access layer
What is the application layer?
provides services for user applications
what is the transport layer?
breaks down the data into packets and sequences it
what is the internet layer?
the packets are sent through different routes to prevent data collision and data traffic, adds the IP address
what is the network access layer?
when data is physically delivered across the harddrive
what are the 4 advantages of layers?
- a layer can be removed/changed; without it affecting any other layers
- Each layer is independent and doesn’t need to know about the other layers
- Allows developers to work on different parts of the layer
- Allow interoperability
what is a network?
more than one computer system connected together which allows communication and sharing of resources
what is a LAN?
network over a small geographical area, usually in a home
wired / wireless
what is a WAN?
connects multiple LANs over a large geographical area
wired
what is a client server network?
clients make requests to a server, the server manages the request and responds
what are the advantages of a client server network? (3)
- can be controlled centrally and easy to backup and update
- hardware/software resources can be shared
- improved scalability, more clients
what are the disadvantages of a client server network?
- traffic congestion can cause the network to slow down
- if a fault occurs with the server, the whole network will fail
what is a peer to peer network?
data is shared directly between systems without requiring a central server
what are the advantages of peer to peer network?
- clients are not dependant on the network
- perfect for quickly sharing files between systems
- easier to add new devices
what are the disadvantages of a peer to peer network?
- backups must be performed on each individual system
- computer performance will decrease with more devices connected to the network
what is a network topology?
layout of computer systems on a local network
(devices on a network topology are called nodes)
what is a star topology?
each computer system is connected to a central device
what are the advantages of a star topology?
new systems can be attached directly to the central system so the network doesn’t need to be shutdown
what is a mesh topology?
each computer system is connected to every other computer system
what are the advantages of a mesh topology?
- if one cable or system fails then the data packets can take an alternative route
- new systems can be added to the network without disrupting the topology
what are the disadvantages of a mesh topology?
- expensive to install and maintain the cables
what are several factors that can affect the performance of a network?
bandwidth available
number of users
layout of network topology
interference (e.g thick wall)
what is a wireless access point?
provides a link between wired and wireless networks
