Ring

Nodes in a ring topology are directly connected to two other nodes which form a loop. A message travels from one node in the ring to the next until it gets to its destination. Usually the transmission of data is only in one direction, unless it is a double ring system where one cable dedicated to each direction.

A message is created by one of the nodes of the ring system, this node waits for the token, which carries all the messages of the system. The node places a message onto this token and passes the token to the next node in the ring. The receiving node recognises the destination of the message it can either read it if it is the intended recipient or pass it on to the next node.

Advantages

  • a single cable is used to connect all the nodes

Disadvantages

  • If one node fails the system will not function
  • If the transmission medium fails the system will not function
  • Since all data is passed from node to node, messages can be intercepted by other nodes (not intended address).
  • Adding or removing nodes will temporarily render the system unusable.
  • Hard to add additional nodes.