Freitas et al. propose virtual topologies to manage inter-domain quality of service (QoS) in next-generation networks (NGNs). They consider several scenarios of “the client and target node movement” and “the client and target node domain movement.” Finally, they analyze and verify the proposed scenarios.

However, the paper has several drawbacks. First, the paper’s organization is unattractive and the clarity of its presentation needs improvement. Besides, the concepts and related work should have been shortened. Second, since mobile QoS has been studied recently, the authors should have compared their proposed approaches with several other recently proposed schemes. In doing so, they would have convinced readers that their proposed scheme outperformed the other mechanisms. Third, in Section 5, the authors fail to give the system parameter for performing the simulation--for instance, what’s the speed of the mobile nodes and what mobility model is used? Finally, the paper’s language problems and presentation skills significantly hamper its readability.

Overall, this paper presents a good idea for managing inter-domain QoS in NGNs. However, it would have been stronger if the aforementioned problems had been addressed.