1. How many people have a VoIP solution on their phones to use over WiFi in a case like this?
2. What is the percentage of homes with twisted pair landlines down to these days?
2. What is the percentage of homes with twisted pair landlines down to these days?
Wi-Fi Calling is a mix of GRE/IPSec tunnels to carrier servers (which were still functioning during the outage) that then hook into cellular infra on the backend (which wasn't working). On my firewall, I was seeing phones make that GRE tunnel connection, but it was just a gaping void after that.
FaceTime does not use cellular infra at all (except as a potential IP network interface)