Multi country support on VoIP switches: Central international switch. - Necip Gözüaçik; Emine Yilmaz; Ferhat Tuncel; Kenan Sahin; Bahadir Özdemir; Ufuk Gurpinar; Ersin Bayramoglu; Oguzhan Yavuz; Ayse Belma Sahin Kaya (SIU, 2015)