Workshop on interdisciplinary systems approach in performance
evaluation and design of computer & communication systems

Networks that are efficient and robust to failures tend to have star–like or homogeneous structures in their connectivity. The choice of optimal structure depends on the network load. The results presented in this paper are: For source–routing networks the change from one structure to another is smooth and does not depends on network congestion. The addition of extra links to the optimal network reduces its overall performance (Braess’ paradox). This performance deterioration is small if the network structure has a narrowly degree distribution centred around the mean degree distribution.