Networking

Networking

1. Local Area Network(LAN)

   • Connects to devices in a limited area such as a school or house
     • Advantages: Peripherals can be shared, Hard drives and CD-ROMs can be shared, users can save data to use on any device, Data can be easily transferred from device to device, Software can be purchased only once and used on all devices, Only the central device needs updating.
     • Disadvantages: Can be hard to set up, All devices affected by a single fault in any device, may need special security

2. Wide area network (WAN)

   • wide area network (WAN) is a network that covers a broad area using private or public networks
     • Advantages: Messages can be sent very quickly to anyone else on the network. These messages can have pictures, sounds, or data included with them (called attachments). Expensive things (such as printers or phone lines to the internet) can be shared by all the computers on the network without having to buy a different peripheral for each computer. -Everyone on the network can use the same data. This avoids problems where some users may have older information than others. Share information/files over a larger area
     • Disadvantages: Setting up a network can be an expensive and complicated experience. The bigger the network the more expensive it is. Security is a real issue when many different people have the ability to use information from other computers. Protection against hackers and viruses adds more complexity and expense. Once set up, maintaining a network is a full-time job which requires network supervisors and technicians to be employed. Information may not meet local needs or interests Volunerable to hackers or other outside threats

3. Client/Server network

   • CS networking is centralised and uses servers.
     • Advantages: A client server can be scaled up to many services that can also be used by multiple users. Security is more advanced than a peer-to-peer network, you can have passwords to own individual profiles so that nobody can access anything when they want. All the data is stored onto the servers which generally have far greater security controls than most clients. server can control the access and resources better to guarantee that only those clients with the appropriate permissions may access and change data.
     • Disadvantages: More expensive than a peer-to-peer network you have to pay for the start up cost. When the server goes down or crashes all the computers connected to it become unavailable to use. When you expend the server it starts to slow down due to the Bit rate per second. When everyone tries to do the same thing it takes a little while for the server to do certain tasks.

4. Peer to peer network

   • Peer to Peer network is a decentralised network where every node uses and gives resources
     • Disadvantages: No need for network OS, Does not need an expensive server because individual workshops contain files, Much easier to set up than Client 2 Server, No need for specialist technicians, If one fails no other nodes are affected
     • Advantages: Files can't be backed up, performance is slow, no centralised strorage files, every computer needs to insure hey dont install viruses

5. Intranet

   • An intranet uses internet protocol to share OSs, programs etc. across a network

6. Extranet

   • A Extranet is a computer network that is accessable from outside of the intranet

7. Stand-alone computer

   • A stand-alone computer isn't connected to a broad network

8. Node

   • A node is a device that is connected to a network

9. Different types of topologys

   • Ring Network
     • Each node connects to adjacent nodes
   • Star Network
     • All devices are connected to a central device
   • Bus Network
     • Every node is connected to one cable

10. Wireless Local area network (WLAN)

    • Covers a broad distance using private or public networks
      • Disadvantages: Setting up a network can be an expensive and complicated experience, Needs very secure and expensive security, Once set up maintaining a network is a full-time job, Volunerable to hackers
      • Advantages: Messages can be sent very quickly to anyone else on the network, Share information/files over a larger area, Data can be shared across the network, Peripherals can be shared

11. Network Policies

    • Acceptable Use
      • This is a set of ground rules created by the administrator of a network. They usually rules things like 'Don't go on any suspicious websites' or 'Don't download viruses'. If the Acceptable use rules are broken it is likely you will be barred from the using network
    • Failover
      • Failovers are ways to prevent disasters. An example is backup or secondary servers. Another example is in case of an power-cut there will be spare batteries (UPS) so the server can continue to run. Raid hard-drives are another example.
    • Archiving
      • This is when old files are compressed and stored in a different part of a hard-drive. This stores old files without taking up space.
    • Integrity
      • This is mainly for the admin. It just means they are trusted, Have high moral standings and won't mess with your data.
    • Disaster Recovery
      • This is ways to recover data etc after a disaster. The main Disaster recovery is backup.
    • Backup
      • This copies information from the main server(s) to a remote location like The cloud or a data farm. This helps prevent Disasters and the backup is unlikely to fail/corrupt/EXPLODE! This should be done daily in businesses
    • Policies
    • Reliabilty