Must’ve been corrected on 1.1.1.1 but I also switched from CellC a year ago. Point I’m trying to make is that it could be a DNS issue, was just using my experience as an example.
One thing I just remember on this topic. While I was on CellC using WiFi calling, I tried switching to 1.1.1.1 for DNS privacy (away from 8.8.8.8). As soon as I did that CellC WiFi calling stopped working.
I wonder if these different ISPs aren’t pointing to a DNS issue. The phone should be...
I’ve done some digging/reading and it seems with iOS there will be something needed from Apple. In the entire Africa, only CellC and Vodacom are listed as supporting WiFi calling. I have a feeling this may have to come with an iOS update in conjunction with certification from Apple...
I think you highlighted the primary benefit in point 1. Unless you roam a lot, where you will save on those charges. WiFi calling (when connected from abroad) would make a local call as opposed to a roaming call.
You would still use your minutes and sms’ but it would use your internet that is...
Do there have to be any router/ISP changes? As far as I’ve read the phone initiates the IKEv2 tunnel which should work on pretty much any standard internet connected router (unless the FW is fiddled with).