I use VOIPo and was also happy to find out that I did not need WOW phone. I was a beta tester of VOIPo and VOPoTim gave us a great annual rate that I don't pay attention to the latest deal from anyone.
It linked but stopped working. WOW_Dan looked at it and enabled 3 VPN protocols, and it was back in action since then.
The built-in 4 port router seems to work fine (I added a switch too), and the wireless connectivity works great for me too, so my Linksys loaded with Tomato firmware is retired for now.
Right now I have two printers via ethernet, two desktops, and a PAP2T, a few phones via WiFi, a Tablet on WiFi, and a laptop occasionally on WiFi.
I did reboot the Media Hub/Cable Modem/Internet access (One box) when everything froze for the TVs. (Three TVs connected.)
That was four or five days running, and a couple weeks+ have passed since then. So it is running reliably (for me).--
Jim, VoIP 12/2002, VOIPo 2/2007