The one advantage Skype has - which was one of their USPs when they first launched - is that its protocol seamlessly traverses NAT routers.

Recently, my wife was visiting her family and although both N810s had worked well with the Internet Call feature built-in when connected to the same WLAN at home, it didn't work at all from within my WLAN to her device inside her parents' WLAN.

So, we tried Gizmo, which at least connected the call but no audio or video was transmitted. We gave up and used a phone instead.

Given most users are a) behind NAT routers on wireless and b) nowhere near as technical as me, how anyone uses these features is beyond me (does anyone use these features?)

Certainly I'd like to get it solved - even if it involves punching holes in my firewall - when I go to JavaOne in May.