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Networks Unit 3 - Coggle Diagram

- - - - Security problems - files sent between computers could spread a virus
      - A network manager may need to be employed which is expensive
        
        Initial cost of servers is also expensive
      - If the server is down, all workstations on the network are affected
        
        Hackers can gain access to files quicker
- - - - Ring
        
        Each node connects to exactly two other nodes, providing a single pathway for signals through each node.
        
        Disadvantages
        
        If any of the computer systems fail, the ring is broken and data cannot be transmitted efficiently
        
        a problem with the main cable or connection and the entire network goes down
        
        It is difficult to troubleshoot the ring
        
        Because nodes are wired together, to add another you must shut down the network
        
        Advantages
        
        The transmission of data is simple as packets travel in one direction only, so no collisions
        
        Adding additional nodes has very little impact on bandwidth
        
        Data is quickly transferred without a bottleneck – consistent data transfer speeds
      - Star
        
        Where one or more central switch, hub or computer acts as a central conduit to transmit messages
        
        Advantages
        
        Good performance/fast network speed
        
        Easy to set up
        
        Easy to add more computer systems
        
        Minimal network collisions
        
        failure of workstations will have no
        effect on the network
        
        Better security
        
        Disadvantages
        
        Expensive to install as more cable is required
        
        Extra hardware required, such as a hub
- - - - Advantages
        
        Easy to add more computer systems to the network without disrupting the network
        
        Quick and easy to set up – well suited for temporary networks
        
        Cost-effective as less cabling is needed
    - - Disadvantages
        
        It is difficult to troubleshoot the bus if there’s a fault
        
        Proper termination is required
        
        Limited cable length and number of stations – performance degrades as additional computers are added
        
        Data collisions are more likely, which causes the network to slow down. A collision is when two computers try to send a packet at the same time
        
        If there is a problem with the main cable or connection, the entire network goes down
        
        Low security – all computers on the bus can see all data transmissions
    - - Sending data over a Star network
        
        Computer A adds computer D’s address to packet
        
        Computer A sends packet to switch
        
        Switch looks at address on packet
        
        Switch compares to stored list of addresses on network
        
        Mesh
        
        Each node relays data for the mesh network. All mesh nodes cooperate in the distribution of data in the network.
        
        This is very reliable as it can 'self-heal' by reconfiguring around broken paths. This network is complex, expensive and difficult to set up. A large part of the network may be redundant
        
        Switch forwards packet to computer D’s address
- - - - Wireless is generally slower in terms of bit rate although the advantage of greater freedom can offset this
    - - Wireless does not use cabling but requires both the transmitting and receiving machine to have wireless network adaptor cards