[swinog] Reliable + Good quality VoIP Provider (US, Switzerland, Korea)

Good morning Swinog,

we are looking for a new VoIP hoster that actually offers decent voice quality, preferable even over hspa(+) based networks, working in the US, Switzerland and South Korea.

Working := can receive / make phone calls well enough for daily use (I am aware that VoIP should work everywhere, but in practice the quality either in Switzerland or abroad or both is too poor to talk for long).

So far we are using telephoenix.com (reseller of $provider), but have huge problems in terms of voice quality (even via wifi via dsl / cable).

I was wondering, if anyone can recommend a provider and also has tested reachability in East Asia and North America?

Cheers,

Nico