Topology
A network topology is the
physical layout of the network. In networking there are three main
topologies in use; Bus, Star and Ring.
Bus
The bus topology is by far the
most popular method for connecting computers. All components of the bus
topology are connected via a backbone which is a single cable segment
connecting all computers in a straight line (theoretically). On bus
networks, the signal transmitted by a computer, is propagated along the
entire length of the network, and is thus called a broadcast system, because
all other nodes hear the transmission.
Star
The star topology is when each
network component is connected by a cable segment to a central hub. Some
confusion is found with regards to the star topology, with two descriptions
being applied. Firstly, it is stated that the signal sent from one computer
to another, is received by the hub, and the message directed to the intended
node. This method is therefore known as a directed system. Secondly however,
some sources say that all nodes connected to the hub hear the transmission
with only the intended node actually downloading the packet, thus a
broadcast system. The first description is most likely the correct one.
Ring
Ring topology networks are
created when a computer is connected directly to the next computer in line,
forming a circle of cable. As each computer receives the signal, it acts on
it, regenerates it, and passes it along. Signals travel in only one
direction on the ring. This topology is used by Token ring networks, see
later. |
