Voznak, Miroslav, Ivo Zbranek, Miralem Mehic, Dan Komosny, Homero Toral-Cruz, and Jerry Chun-Wei Lin. 2016. “Covert Channel in RTP Payload Using a Pointer in Sip Header”. Communications - Scientific Letters of the University of Zilina 18 (1), 40-47. http://journals.uniza.sk/index.php/communications/article/view/376.