I wonder if selecting "low data usage" has any effect - i.e., is the purpose to lower the data usage charge for someone on a metered connection by forcing a higher compression codec, rather than to tell the app that there will be a slow connection. I would think/hope that the app would detect if it is a low bandwidth connection and automatically compensate.
Originally Posted by
CatJo
I recently used T-Mobile's 2G international roaming and primarily made WhatsApp audio calls - like you, I found the quality to be good and latency did not appear to be a problem at all. I did have the "low data usage" option for Calls selected.
I made a few FaceTime Audio calls too and they were just fine as well. Unfortunately, I forgot to try Google Hangouts and Bria with VoIP.ms (or other providers); I imagine they'd be fine.