Hello dudes... I've compared an installation of 3cx on a virtual server microsoft based and a standard server installation. both hardware systems was a 3gb server with dual core 2ghz cpu. Standard Server is very fast, no added lag on voice. fantastic quality. Virtual server introduces a lot of little problems. No good voice quality, choppy sound. no more than 2-3 contemporaneous calls. a lot of LAG on voip calls. I suggest to install 3cx Always on a real server and not on virtual!!!