Almost any internet capable STB with real internet functions (not pirate) will "phone home" one way or another.
If it uses internet services from the manufacturer or distributor it obviously connects and identifies for those. If it has online firmware updates it has to "phone home" to check for new firmware and to get it.
NTP (internet time) uses public time servers so a STB does not need to call to anywhere but the NTP server(s) being queried to use it.
Even some limited Apps can phone home in a way, for example Goolgle Maps, Youtube and others that use a API. The API key identifies who built the app and that person can normally collect all sorts of statistics VIA the provider from those using the app.