For evaluating heuristic and optimal network revenue management procedures test-instances are needed. As a consequence when trying to create instances for network revenue management problems it turns out that among other things a stream of stochastic demand data is required. But, developing and implementing a generator for demand data that fits to a given network, a given set of products, and a given set of capacity constraints is far from being easy. Since to the best of our knowledge no such demand data generator is available to the public, we specify an algorithm to generate this data and we also make this algorithm available upon request. This, we hope, facilitates future research work.