Originally Posted by BigFlyer

That chart is interesting, but does not compare quality across different VOIP providers at low bandwidth.

I think depending on where you are calling the latency might also be less than one might think.

If you just run a speed test - most of the apps use GPS to determine the nearest speed test server. So, if you are in France, the speed test (and ping test) would go from France to the US via the VPN, US to speed test point in France (as selected by phone using GPS), Speed test point in France back to US, then US back to your phone in France via VPN.

If you were making a Skype call to a point in the US the call would go to the point in the US via the VPN, then back to France via the VPN. So, that's two transatlantic hops using Skype to call the US vs. 4 transatlantic hops with the speed test.

I had a Whatsapp call to my friend who was in Germany a few weeks ago roaming with the free Tmobile data and the voice quality was very good, with much less latency than I was expecting.

I will test my theory on latency next time I travel (now a few months away) by doing a speed test with the GPS selection of a speed test location and then by selecting a US location manually.