We address the challenges described above by establishing a differentiation between model-oriented (i.e. specific) topology generators, and a universal topology generation tool. Model-oriented generators are those generators designed and implemented with a specific set of models in mind. All the generators described above fall in this category. In contrast, a universal generator should not be tied to a specific model or set of models. Instead, this generator should be extensible, allowing the addition of new models in an easy way. This characteristic makes a universal topology generator flexible and adaptable, generating representative topologies to be used in different simulation scenarios. In addition a universal topology generator should be robust. It must be as efficient as possible without sacrificing robustness. Finally, a universal generation tool must integrate to existing network simulation tools and be user-friendly.