Some examples of comparisons of connecting networks

In the theory of telephone traffic it is of interest to compare the performance of connecting networks, as measured by the probability by blocking, when they are subjected to the same traffic sources. The question arises whether there are examples of pairs of networks, with the same number of cross-points, whose respective graphs of loss as a function of offered load cross each other. The existence of such examples would establish the principle that some network configurations are inherently more efficient at some traffic levels than at others, so that the “excellence” of a network is not necessarily a purely combinatorial notion independent of offered traffic. Examples of the above phenomenon are exhibited which do not involve only very small networks.