Download Networks

Networks
What is a network?
• two or more computers linked together.
What does network allow users to do?
• to share software and hardware
What are Local Area Networks (LANs)?
• Networks that link computers within a
limited area (a department, an office, or a
building).
What are Wide Area Networks (WANs)?
• Networks that link computers across the
world.
What advantages do networks have?
- increase productivity
- workers can share information easily
without printing, copying, telephoning,
or posting.
TOPOLOGIES
• Computers in a network can be connected in
3 basic topologies:
a star topology
a ring topology
a bus topology
Star topology
Describe the star topology
• a server computer is at the centre and a
separate cable connects the server to the
other computers in the network.
What does the central server control?
• The central server controls the flow of data
in the network.
What happens if the central server fails?
• If the central server fails, the whole network
Ring topology
Describe the ring topology
• each computer is connected to its neighbour
in a circle, the data flow in one direction
round the ring.
What happens if one computer fails?
• If a cable breaks or one of the computers
fails, the whole network will fail.
Bus topology
Describe the bus topology
• all the computers are connected to a
common cable, the data flow in both
directions along the cable.
What happens if a computer fails?
• If a computer fails, or we remove one from
the network, the other computers won’t fail.
Mesh topology
Describe the mesh topology
• every computer is connected to every other
computer, is not commonly used.