A Path Diversity Metric for End-to-End Network

Path diversity is an important index of the dependability and fault tolerance capability of networks. Most path diversity metrics are designed under an implicit hypothesis that all candidate paths for a divergence node are always equally chosen. This may not be true due to the effect of routing policy with consideration of cost or other factors. A new simple metric is proposed in this paper for path diversity measurement of end-to-end networks. An end-to-end network is firstly transformed into a sequence of cascading segments. With the assumption that only one of all available branches is chosen each time, a probability based metric is calculated for each segment, and the joint entropy is calculated as path diversity measurement for the overall end-to-end network. The metric is fitful for both single-hop and multi-hop topologies. A comparison between the new metric and other ones is given at the end.