Star Ring Bus





Network topology refers to the way in which the connections within the network are made.  There are two types of topology they are;


The physical topology

The logical topology


The physical topology is how the computers and peripheral are connected and how the cable is run between them, in other words the way the network looks.  The logical topology describes the way in which a network transmits information from one node to the next node.


The three common physical topologies for Local Area Networks are;






Other less common physical topologies include;





The most common logical topologies are;


The Bus Logical Topology

The Ring Logical Topology


The Bus Logical Topology


 In the Bus Logical Topology each time a node on the network has data for another node, the sending node broadcasts the data to the entire network.   The various nodes hear it and look to see if the data is for them.  If so, they keep the data.  If not they ignore the data.  Ethernet is the best known example of a logical bus network.  A physical topology does not have a direct bearing on the logical topology.  It is possible to have a physical star and a logical ring or a physical star and a logical bus and so forth.

LocalTalk is also another example of a logical bus network.


The Ring Logical Topology


 In the Ring Logical Topology only one node can send information across the network at any given time. This is achieved by way of a token.  The Token Ring and Fiber Distributed Data Interface are examples of a Logical Ring Network


To read more on topologies go to Computer Networks by Dr Derek Hill