Computer networks and topologies Flashcards
What is a Network
Two or more computers that are connected for the purpose of communication
Advantages of Using Networks
File sharing - Users can share files with others
Hardware sharing-users can share hardware with others
Communication-Users can communicate via email etc
Roaming access -Users can access files on any computer
What are the benefits for larger organisations of Networks
Centralised maintenance+Updates - Software managers can Schedule Updates for all computers
Centralised security - Software managers can implement a fire-wall or antivirus across a network protecting user files
User Monitoring - Network managers can see what users are doings
Disadvantage of Networks
Cost - Can be costly to buy equipment needed
Management - You need special staff to manage it
Spread of Malware - Malware can easily be transferred
Hacking - Someone may access data without permisson
What is a LAN
Local area Network - geographically confined to one site A group of devices connected by a Hub or switch
What is a WAN
A Wide area network Can be used by banks with other branches etc Can be unlimited in range Each LAN is connected using the WAN
What are the factors that affect Network performance
Bandwidth
Number of Devices Connected to it
Network Latency
Type of Traffic
What is Bandwidth
The amount of Data a transmission medium can transfer over a given period of time
What is the typical Bandwidth for Twisted copper wire,Fibre optic,Home WIFI and Business WIFI
Twisted Copper Wire - Up to 10 Gigabits p/s
Fibre optic - Up to 100 Gigabits p/s
Wi-Fi - Up to 600 Megabits p/s
Business Wi-Fi - Up to 6 Gigabits p/s
If One device is allocated 50MB p/s how much will 2 devices be allocated
25 each
What is Latency and which Network type Experience more Latency Hub or switch and why
Time taken for a message to be sent to one device from another
Hub because it broadcasts messages to all devices wasting bandwidth on sending messages to unnecessary devices
What are Transmission Errors
When two devices try to communicate the same time their signals collide and they cancel each other out
What are the two models of Connecting computers over a network and how they work and give an example
Client-Server Network - A Server/Computer Manages and stores files They control the network E.G File servers web servers mail servers best suited for organisations with many computers
Peer to Peer Network - No Computer has Control over another All equal each computer is known as a peer best suited for organisations with few computers
What Hardware is Required to create a Network
A Network Interface controller (NIC) : Offers Interface Port for wired connections and Radio receiver for Wireless. Provides a Method of Connecting to the network
A Transmission media - Carries the data via cables or radio signals
Network Connection devices - allows Computers to connect
What are the 4 types of network connection devices and how they work
Hubs- Allows wired devices to connect with each other any traffic is transmitted to all devices Slowing down network performance by sending unnecessary signals + They don’t know which devices are connected
Switches- Same as Hub But knows what devices are connected And sends traffic to intended recipient only improving network performance
Wireless Access points - Uses wireless transceiver to allow wireless connections sends wireless traffic it receives onto main wired network
Router - Used to send data signals across the internet work by collecting knowledge of available routes and determines the best one. usually have a built in wap and modem (allows users to connect to the internet)
