Behavior of a Packet-Switched Lattice Network Model with Inactive Sites
Chen Mao · Chinese Journal of Computers · 2005
Re-considering basic principles of topology and routing is significant to overlay architectures. In this paper, impacts of topological asymmetry to the critical traffic behavior are studied in a Cellular Automata model with inactive cells. Previous approaches showed that phase-transition happened globally in regular Cellular Automata networks and the critical traffic was inversely proportional to the free delay. In the model proposed here, however, the global critical traffic becomes much worse as there are a significant number of inactive sites. The asymmetry in topology differentiates the queuing states of the cells over the lattice space, and therefore, it causes a set of fixed vulnerable points, is much more easier to be congested than elsewhere. For an overlay architecture, improvement of the free delay is significant when the critical traffic achieves the inverse-proportional law, but the topological asymmetry makes it less effective. Fortunately, the observation inspires that the vulnerability of a network can be predicted in order that necessary actions are taken at the vulnerable points on the application leyer.