voip 5 Bloquear Ataque Sip No Mikrotik 16/01/2012 Asterisk The Future Of Telephony 2nd Editon 16/01/2012 Skype Libera Codec De Udio 05/03/2009 Mean Opinion Score 26/12/2008 Desabilitar Autonegociao 01/12/2008