My grandparents solved that by putting their mobile phone number on their door. They're slow to come down and open the door so it makes sense for the post person or visitor to know they're on their way

Relatively low tech compared to somehow hooking up a camera livestream system to ring your phone via the internet in some way but it works

As far as I've tried, it's fully functional if you VPN into your LAN.

Sorry for bugging you about this. I'm not the person you are responding to but this is important to me before buying so if you don't mind, could you verify that this is your setup?

1. The doorbell cam is connected only to the LAN.

2. The doorbell cam is definitely blocked from accessing the internet.

3. Having access to the LAN from your phone through VPN allows you to watch the feed and talk to people at the door through the app.

1. Correct

2. I have not gone through the trouble of isolating them on their own VLAN, but I don't see any traffic coming from the devices. This is something you will want to audit on your own network if it is important to you.

3. I have viewed the camera output through VPN, but have not yet tried speaking through the doorbell (or through one of my camera's audio output). I don't see why it would not work.

Thanks for taking the time!

Depending on your technical abilities, you can set up Frigate or maybe Scripted. Or possibly even just the Home Assistant integration. All of these would be self hosted options, accessible only by LAN if that's how you want it.

The Reolink doorbell camera is a typical recommendation and can work fully locally and supports well the common standards like RTSP. 2 way audio works as well.

I believe the NVR Reolink sells can also work fully locally as well. Which also can integrate to home assistant.