These are home wifi thermostats allows remote Internet access to the thermostat through a computer, tablet, or smart phone using Honeywell's Total Connect Comfort Service:
https://customer.honeywell.com/en-US/Pages/Product.aspx?cat=HonECC%20Catalog&pid=TH6320WF1005/U&....
As near as I can tell, the system uses MAC addressing to identify the device to Honeywell's servers. Does this bypass the IPV6 connectivity problems we've been discussing with security cameras, similar to how a Voice ATA device gets around this issue?