Topologies Flashcards
Star
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In a star network, each computer system is connected to a central node, also known as a hub.
Bus
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The computer systems, also called nodes of the network, are each connected to a single cable on which data can be sent, called the bus. A bus network has terminators on each end, which is needed to ensure that the network functions correctly.
The bus carries packets along the cable. As the packets arrive at each computer system, it checks the destination address contained in the packet to see if it matches its own. If the address does not match, the computer system ignores the packet. If the address of the computer system matches that contained in the packet, it processes the data.
Ring
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In a ring network, computer systems are connected in a ring or a loop. Packets are sent around the ring, being passed from one computer system to the next until they arrive at their destination.
Mesh
Everything is connected to everything.
Advantages of Bus
Easy to implement and add more computer systems to the network
Quick to set up – well suited for temporary networks
Cost-effective – less cabling
Disadvantages of Ring
If any of the computer systems fail, the ring is broken and data cannot be transmitted efficiently
If there is a problem with the main cable or connection, the entire network goes down
It is difficult to troubleshoot the ring
Because all nodes are wired together, to add a another you must temporarily shut down the network
Disadvantages of Star
Expensive to install – more cabling required
Extra hardware required, such as a hub
Disadvantages of Bus
It is difficult to troubleshoot the bus
Limited cable length and number of stations – performance degrades as additional computers are added
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
Proper termination is required
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
Advantages of Star
Good performance/fast network speed
Easy to set up
Possible to add more computer systems without taking the network down
Any non-centralised failure will have very little effect on the network
Minimal network collisions
Better security
Advantages of Ring
Data is quickly transferred without a bottleneck – consistent data transfer speeds
The transmission of data is relatively simple as packets travel in one direction only
Adding additional nodes has very little impact on bandwidth
It prevents network collisions.
