Please, advise... I'm trying to understand this...
OpenSource-Ghost Carrier WiFi xalling uses IPSec tunnel, which is an old and insecure VPN protocol and usage of WiFi calling opens you to more attack surface"
So, are you saying that Carrier Wi-Fi calling is open to more attack surface? WiFi calling, in general? Or that WiFi calling via Carrier WiFi calling enabled is open to more attack surface? And what do you mean my more attack surface? More than simply using a SIM and carrier for communication?
OpenSource-Ghost Each carrier uses its own domains for WiFi calling and your phone should only try to resolve such domains if SIM card is inserted and active, but your phone continues to try to resolve those domains when connected to WiFi in Airplane mode even if SIM card is disabled + WiFi calling itself is disabled!
I have read this over and over again, and can't wrap my head around it. You're saying that if you insert a SIM, your phone will endlessly try and resolve carrier WiFi domains, with the SIM card disabled, whilst connected to WiFi, in airplane mode, with WiFi calling disabled? How? Why? If the phone isn't asked to connect to WiFi, why would it be trying to resolve domains? Is this the same regardless of your phone's DNS settings?
OpenSource-Ghost Carrier WiFi calling doesn't use specified private DNS servers from Android settings. It uses WiFi network's specified DNS addresses.
In light of this, I guess that means that your phone's DNS settings are irrelevant. So, it uses WiFi specified DNS? Meaning the home network that you are using, for instance, not the carrier's WiFi network? And if you are referring to your home WiFi Network, can anything be done on that end with DNS and VPN settings that would make a difference? Is this problem all due to the eternal attempt to resolve domain?! Whether WiFi calling is enabled or disabled, it's all the same? This is super confusing.
OpenSource-Ghost That means the WiFi network to which you connect immediately knows that someone with phone with your carrier is connected to it, even though no actual carrier WiFi calls are possible when its disabled.
But, if you have never inserted a SIM, can WiFi calling be acheived? And are you any less exposed? Does your home network DNS and or VPN settings, or your phones DNS and or VPN settings make any difference with being identified by your home network WiFi provider?
OpenSource-Ghost The only way around that is to connect to your own WiFi network that blocks carrier WiFi calling domains via local DNS server/forwarder (like Pi-Hole) and/or IP's to those domains.
So, this whole thing can be circumvented via PiHole? With and/or without the presence of a carrier SIM? And are you saying this isn't optimal due to the lack of portability? Or something else? It would work ok for at home base, where ever it is that you set that up, though, right?
And, would any of this carrier WiFi calling issue be mitigated by toggling off "Mobile data always active" in Developer options?
My primary concern is that whilst Google and Apple are massive privacy invading whores, mobile carriers are worse, because it seems like there are ways to shut down Google, Apple and the like, but mobile carriers don't just know you're number, your name (if you have to register your SIM with ID), where you are at any given moment, who you know and communicate and spend time with, your lifestyle choices and habits, etc., they also collect and store every conversation and every text and every picture or video you send! In my mind they are the worst! I know, if I choose to use a cellular device for telecommunication, there's not much that can be done to keep certain aspects out of their servers, but it would be great to be able, at bare minimum, to keep conversations, and conversational content from them. So, is this goal able to be achieved using services like Signal, and email? And can these be done with your phone, without a mobile carrier? And/or with a mobile carrier? What even ARE our options? It seems awfully bleak.