WIRED AND WIRELESS NETWORKS Flashcards
What are the advantages of networking?
Users can share files
Users can access their files from any computer on the network
Servers can control security, software updates ad backup of data
Communication with other people
What is a LAN?
A local area network that covers a small geograhical area located on a single site.
All hardware is owned by the organisation using it.
LANS are wired withe UTP cabled, fibre optic or wireless using WIFI.
What is a WAN?
A wide area network covers a large geographical area that connects LANs together.
The Lans are connected by telecommunication companies who manage and own it.
WANs are connected with satalite links, telephone lines or fibre optic cables.
What are some disadvantages of networking?
Increased security risks
Malware and viruses spread very easily between computers
If a server fails, the computers connected to it may not work
The computer may run more slowly if there is a lot of data travelling on the network
What are the 5 factors that affect the performance of a network?
Bandwidth
The number of users
Transmission media
The error rate
Latency
What is bandwidth?
Bandwidth is the amount of data that can be sent and recieved successfully in a give time
NOT A MEASURE OF HOW FAST but a measure of HOW MUCH data
Measured in bits per second aka bit rate
Why does too many users affect the performance of a network?
Too many users or devices on the same network will slow it down due to the insufficient bandwidth for the data.
How does transition media affect the performance of networks?
Wired connections have a higher bandwidth than wireless connections
Fibre optic cables have a higher bandwidth than copper cables
How are error rates increased and what do they do?
With less reliable connections, this increases the number of errors that occur when data is transferred, meaning data must be resent until arriving correctly.
What is the signal quality of a wireless connection and a copper cable connection?
Wireless connection is dependant on the range of devices from the wireless access point and other environmental factors.
Copper cables are determinded by the grade of material used which reduces interference.
The length of the cable is also a factor.
What is latency and what causes it?
Latency is the delay from transmitting data to recieving it.
Latency is caused by bottlenecks in the infrastructure of the network.
What is a server and what can it do?
A server controls access and security to one shared file store.
This could be:
- Managing access to internet
- Managing printer jobs
- Providing email services
- Running backups of data
What does a client do?
A client makes requests to the server for data and connections
What is a Client-server model?
A network with a server
What are the advantages of a Client-server model?
Easier to..
manage security files
take backups of all shared data
install software updates to all computers
What are the disadvantages of a Client-server model?
Can be expensive to setup and mantain
Requires IT specialists to maintain
The server is a single point of failure
Users will lose access if server fails
What is a peer-to-peer model?
A network without a server and all peers (computers) are equal
Peers server their own files to eachother, responsible for their own security and backups + usually have their own printers
What are the advantages of the peer-to-peer model?
Easy to maintain
Specialists not required
No dependancy on a singular computer
Cheaper to set up
No expensive hardware required
What are the disadvantages of the peer-to-peer model?
Network is less secure
Users will need to manage their own backups
Can be difficult to maintain a well ordered file store
What is a network interface card / controller?
They use a protocal (SET OF RULES) to determine how the connection should work and allow a device to connect to either a wired or wireless connection.
What is a Wireless access point and its properties?
A wireless access point allows wireless enabled devices to connect to a network without cables.
Its convinent
Disadvantages of wireless connections?
Security is more of a concern
Connection sometimes isn’t as strong / reliable as wired connections
What does a switch do?
Sends data between computers on LAN and segment the network by forwarding traffic to the correct location.
Switches learn which devices are connected and understand how to forward traffic.
What does a router do?
Sends data between networks
It creates a WAN from a number of LANs. You can not connect to WAN without one.
A router uses an IP address to route traffic
