Onemax gives externai IP (200.89.x.x) and all protocols are open for use. It has standart ethernet RJ45 connector and DHCP. So, it should work. I use scype - it works perfect. If you are in S.D. you can try it with my Onemax, I am using it.
I'm going to be in Santiago, but someone told me the covrage is good there. So, from what your saying, I can connect a router to this thing and use multiple devices? My work requires the Vonage and my PC.