Effects of topology on the performance of localized QoS routing algorithms

Localized Quality of Service (QoS) routing is a viable alternative to the QoS routing algorithms that use global network state information to make routing decisions. In localized QoS routing algorithms each source maintains a predetermined set of candidate paths for each destination and avoids the problems associated with the maintenance of global network state by using locally collected flow statistics and flow blocking probabilities. This paper presents an investigation that considers the impact of topology configurations on the performance of localized QoS routing algorithms. A method is also presented that demonstrates how the performance of localized QoS routing algorithms can be significantly improved by some relatively minor changes in topology. Our results are obtained using simulations of a variety of network configurations and show that the performance of localized QoS routing algorithms is affected significantly by the level of connectivity.