Ict networks

• Networking hardware includes routers, switches, hubs, modems, and cables.
• the network will fail if the central computer/server malfunctions
• Cabling installation, management and equipment for a star network is more expensive than a ring network
• Star network


  • Increased security - if one computer is not working, the rest are not affected
  • Additional computers can be easily added by connecting to the file server
  • High performance, no collisions
• Ring network


  • Each computer directly connected to two other adjacent computers to form a ring
  • Data passes from one workstation to another in one direction
• To add a new computer to a ring network, the cable between two existing computers has to be broken and each part attached to the new computer
• Ring network traffic can pass through the network interface of each device, or the devices can be connected to the central ring by spurs
• Ring network


  • Very easy to implement
  • Workstations can be added easily
• If the bus cable has to carry traffic for a large number of devices, the efficiency of the backbone will drop
• A fault in the bus cable will cause the network to fail as all communication breaks down
• A bus network is less secure than a star network as each device has access to the bus and data could be intercepted
• Terminator


  Stops the signal returning/bouncing back down the backbone cable, to absorb the data
• Router


  • A sophisticated switched hub that holds information about computer addresses and forwards data efficiently using IP addresses
  • Used as a gateway to connect a LAN to a larger network like the internet
  • Can monitor traffic and limit access for certain sites or users
  • Can be wired or wireless
• A wireless router is also known as a Wireless Access Point (WAP)
• Network topology


  The theoretical arrangement of the components of a network
• Network interface card (NIC)

  • An electronic circuit board built into a computer to allow it to be connected to a network
  • Allows the computer and file server to communicate
• Wireless Network Interface Card (WNIC)


  Allows a computer to connect wirelessly to a router
• File server


  • The main computer on the network, with large RAM and hard disk space
  • Stores user files and manages network security
• Fibre optic cables


  • Do not corrode
  • Have large data capacity
  • Can support multiple services at the same time
• Fibre optic cables are more expensive than copper wiring and expensive to install
• Mobile broadband


  • Delivery of internet service using mobile phone technology
  • Requires a 'dongle' or portable modem for devices without built-in hardware
• Mobile communication technology


  • Flexible access, high speed transfers with 4G, allows access to TV, gaming, social media etc.
  • Better at penetrating buildings than 3G
• Mobile communication technology speeds are limited by mobile signal strength, which may depend on location
• Unlimited mobile data usage is expensive, with other options capping usage
• 4G coverage is increasing but not universal, and 4G frequencies may be incompatible across countries
• Mobile communication technology has high battery consumption
• Bluetooth


  • Short range wireless communication standard to connect devices
  • Devices must be 'paired' to communicate
• Bluetooth


  • Can be used to pair devices like headphones and activity trackers
  • Automatic sensing - devices reconnect when in range
  • Low power requirement
• Bluetooth has short range, usually less than 10 metres, and slower data transmission rate than other wireless technologies
• Optical fibre


  • Bundles of fine glass strands that carry data as pulses of light
  • Allows rapid data transmission and is better for long distance communication than electrical cables
• Optical fibre is more expensive than copper cables, so is often only cost effective for very high bandwidth demand
• Unterschiede zwischen Internet, World Wide Web, Intranet und Internet der Dinge

  • Das Internet ist das Netzwerk miteinander verbundener Netzwerke
  • Das World Wide Web ist ein Dienst/eine Anwendung, die das Internet nutzt, um Webseiten zwischen Webservern und einzelnen Geräten zu übertragen
  • Ein Intranet ist ein privates Netzwerk, auf das nur autorisierte Nutzer einer Organisation zugreifen können
  • Das Internet der Dinge ist das Netzwerk von Geräten, die die Fähigkeit haben, sich direkt mit dem Internet zu verbinden
• World Wide Web


  Anwendung, die auf dem Internet läuft und die am häufigsten genutzte Dienstleistung im Internet ist
• World Wide Web


  • Webseiten sind in der Programmiersprache HTML geschrieben und werden in einem Webbrowser angezeigt
  • Kommunikation im World Wide Web erfolgt über das Protokoll HTTP
• Das Internet ist ein WAN, da es ein weltweites Netzwerk ist, in dem Computer an geografisch getrennten Standorten über Satelliten miteinander verbunden sind