IP multimedia subsystem. siete budúcich generácií. open-source softvér. VoIP technológieKováčik, Tomáš Building NGN and VoIP Services on Open Technologies. Kotuliak, Ivan, 1974- In: Praha : CESNET, 2010. -- IP Telephony workshop 2010, April 29-30, 2010, Prague, CzR. -- s.24 s.