From the FAQ: http://superuser.com/faq

> Super User is for computer enthusiasts and power users. If you have a question about …

> - computer hardware computer
> - software personal and home
> - computer networking

> 
> and it is **not** about …
> 
> - videogames or consoles
> - websites or web services like Facebook, Twitter, and WordPress
> - electronic devices, media players, **cell phones or smart phones**, except insofar as they interface with your computer
> - issues specific to corporate IT support and networks
> - a shopping or buying recommendation

The exception for cell phones and smart phones, "*except insofar as they interface with your computer*", does not apply here, as TCP/IP communication (and VoIP) on these phones happen without the interaction of a computer.