Sparks07'

@inproceedings{DBLP:conf/lisa/Sparks07,
  author    = {Robert Sparks},
  title     = {VoIP with NATs and Firewalls},
  booktitle = {LISA},
  year      = {2007},
  ee        = {http://www.usenix.org/events/lisa07/htgr_files/sparks.pdf},
  crossref  = {DBLP:conf/lisa/2007},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}

@proceedings{DBLP:conf/lisa/2007,
  title     = {Proceedings of the 21th Large Installation System Administration
               Conference, LISA 2007, Dallas, Texas, USA, November 11-16,
               2007},
  booktitle = {LISA},
  publisher = {USENIX},
  year      = {2007},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}