Star And Mesh Topologies

• A layout of computer systems on a local network.

• Each computer system is connected to a central device, usually a hub or switch.

1) - Each computer system is connected to the central hub or switch and transfers its data packets there. 2) - The hub or switch looks at the destination address and transfers the packets directly to the intended computer.

• Improved security because data packets are sent directly to and from the hub / switch in the centre and not necessarily all devices like in a bus or ring topology. • New systems can be attached directly to the central system so the network doesn’t need to be shut down. • Transfer speeds are generally fast as there are minimal network collisions.

• Extra hardware (the hub/switch) is required to be purchased, installed and maintained. • If the central system (hub/switch) fails, then the whole network will be unusable until the error is fixed.

• Each computer system is connected to every other computer system.

• Where some nodes (e.g a printer) are connected to every other node.

• Data packets are transferred to the destination address along the quickest path, travelling from node to node. • If a pathway is broken, there are many alternative paths that the packets can take.

• If one cable or system fails then data packets can take an alternative route and still reach the destination address. • Because of the large possible number of systems and connections, a mesh topology can usually withstand large amounts of data traffic. • New systems can be added to the network without disrupting the entire topology.

• Because of the possibly large amount of cables required, this can be expensive to install and maintain. • Redundant cabling should be avoided - this is when cables are connected between systems that won’t ever need to communicate.

• When cables are connected between systems that won’t ever need to communicate.