@INPROCEEDINGS{bacioccola07user,
  author = {A. Bacioccola and C. Cicconetti and G. Stea},
  title = {User-level Performance Evaluation of VoIP Using ns-2},
  booktitle = {Proc. {NSTools} 2007},
  year = {2007},
  address = {Nantes, France},
  month = {oct}
}