?url_ver=Z39.88-2004&rft_id=10.1109%2FICICT.2011.5983558&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aufirst=F.&rft.au=Sattar%2C+F.&rft.aulast=Sattar&rft.title=A+secure+architecture+for+open+source+VoIP+solutions&rft.date=2011&rft.isbn=9781457715532&rft.genre=proceeding