The manual doesn't explain the meaning of the following UPnP settings:

Enable Connection control Service
Enable Connection Status Service

I was hoping someone here knows what they do.

I don't personally use UPnP with my 2820 as I've never found it to work.

Connection Control allows UPnP clients on the LAN to start/stop the gateway, i.e. bring the internet connection up/down.

Connection Status allows clients to see the presence of the gateway and obtain status info from it. I think actually the status is broadcast on the network via XML messages.

This is my best guess but I don't know much about UPnP because, as mentioned, it's never worked for me with Draytek

C.