Simulation Study of the Capacity Effects of Dispersity Routing for Fault Tolerant Realtime Channels

The paper presents a simulation study of the use of dispersity routing to provide fault tolerance on top of a connection oriented realtime service such as that provided by the Tenet scheme. A framework to study the dispersity schemes is presented. The simulations show that the dispersity schemes, by dividing the connection's traffic among multiple paths in the network, have a beneficent effect on the capacity of the network. Thus, for certain classes of dispersity schemes, we obtain a small improvement in fault tolerance as well as an improvement in the number of connections that the network can support. For other classes of dispersity schemes, greater improvement in service may be purchased at the cost of decrease in capacity. The paper explores the tradeoffs available through exhaustive simulations. We conclude that dispersity routing is a flexible approach to increasing the fault tolerance of realtime connections, which can provide a range of improvements in service with a corresponding range of costs.