This parameter determines how the messages involved in a distributed operation are sent.
Many factors go into deciding which topology is optimal.
First, the user must decide if any processor is more important than others. For instance, if the source processor's time is more important than other processors', a ring topology is often optimal. On the other hand, if everyone needs the information quickly, some type of tree is often best. Some topologies tie up the sending processor for large amounts of time, and different processors get the information at different times depending on topology. Noisy algorithms will cause problems on systems where network conflicts are problematic.