I never noticed this item in the 101 as the symptoms was not included with the tip in the 101. I was troubleshooting the exact same issue with my DB1 for the past month. While the DB1 never actually disconnected from the wifi, it would restart the RTSP stream every 3 minutes, which appears as a signal loss / disconnect in BI and when using VLC. As Alex pointed out recently to another user, there is semantics in the usage of the word as "disconnect" as it implies it disconnected from the network to him (while others simply indicated the symptom which was that BI/VLC stops receiving the stream and would try to reconnect to the camera after a few seconds implying it disconnected from the camera, not the network).
Switching my access point from EAP120 to a EAP245 and switching band from 2Ghz to 5Ghz didn't solve it. I already had my firewall (an EdgeRouter) open to allow the DB1 unrestricted access to the internet.
Yesterday, while troubleshooting an NTP issue between my newly install GS324T Managed Pro switch and my EdgeRouter, I enabled logging on the local interface firewall since the traffic between the switch and the router would never leave the VLAN to find the NTP packets, I found the DB1 ICMP packets getting sent to the local interface on its VLAN and were getting blocked as I only allowed NTP and DNS to all devices on the local interface, and SSH and GUI port access only to "admin" devices. I added allowing ICMP packets to the local interface for just the DB1 VLAN, and the DB1 has now been running smoothly without the constant 3 minute restarts of the RTSP stream.
While I had allowed unrestricted access to the internet, and unrestricted access to NTP and DNS on the local interface (gateway router), I didn't allow ICMP pings on the local interface.
Like you said Ronin, you need to ensure that the DB1 can ping its gateway IP address, otherwise, the DB will stop and restart the RTSP stream every 3 minutes, while not disconnecting from the network itself.
Now, I just need to review my DB1 firewall logs for the past month to isolate all the IP addresses and ports it communicates with on the internet so that I can lock down the DB1 firewall policy. The list of ports that cool77 mentioned did not work for me at the beginning which is why I have allowed unrestricted internet access.
@David, can you revise the 101.
In your Firewall settings, allow ICMP from the Doorbell to your router, otherwise you will lose the RTSP stream every 3 minutes in BI, VLC, etc.
the doorbell will disconnect/reconnect the WiFi
Remove the disconnect/reconnect the Wifi as that never showed up in my AP logs and the normal cloud apps did not appear to lose its streaming connection either.