After spending some time with the Apple Support Team without getting a reasonable answer, I hope to get one from the devs forums.
This behavior is observed with iOS 10.3.1 (14E304)
The problem is that I am charged for data usage in roaming when my Cellular Data Options is "Roaming Off". "Cellular Data" is ON, but I don't think this should matter. Moreover "Current Period Roaming" shows 0 bytes.
What I get as an answer from the support team is that
1. 0 bytes does not necessarily mean really 0 (it might show 0 and the actual usage to be even in MBs)
2. Even if Cellular Data Options is "Roaming Off", apps can use cellular network to complete started background operations (e.g. checking email, polling messages from facebook, or whatever)
I can't see any reasoning in that. I would exepect that anytime phone switches from/to cellular/wifi network the existing connection is disconnected and a new one is created. In that context before establishing a connection I assume the following checks.
1. Check if wifi accessible (including provided credentials). If yes connect to it.
2. If not 1, then check if Celullar Network is accessible. If no, then no connection => no traffic. If yes, go to 3.
3. If not in roaming => connect, if in roaming go to 4
4. Data Options is "Roaming Off" => no connection => no traffic, otherwise - connect
(Intentationally missed a few branches in the workflow like ON/OFF for cellular data to keep it simple)
Following that workflow, I can't see the reason why any traffic should be counted if Data Options is "Roaming Off".
Also "Current Period Roaming" is in bytes. If 0 bytes does not mean 0 bytes, why do I have that stat in bytes? Apparently it is misleading and in my case it costs $15 for nothing.
Looking forward to any reasonable explanation.
Thanks,
Todor
