A Model of Joint Congestion Control and Routing Through Random Assignment of Paths | NIST

We investigate the trade-o between utility and path diversity in a model of congestion control where there can be multiple routes between two locations in a network. The model contains a random route allocation scheme for each source s where the degree of randomness and therefore path diversity is controlled by hs, the entropy of the route distribution. After deriving the model from a network utility maximization problem we analyze it in detail for two sample topologies. We conclude that, starting from an allocation with maximum robustness and path diversity, one can always increase the utility by decreasing hs. However it can only decrease until a critical value of the entropy is reached. The value depends on the topology and link capacities of the network and can be explicity computed for our examples.