We have 820 and 830 devices in the field. We can access them from our office and administrate them via the public IP address. However, unlike the 560s, 550s and 6xxs we have not been able to administrate them thru the VPN via their local LAN IP.

In the RF820 / RF830 administration access, you need to setup the network in the Allowed column in order for the remote to webadmin into the RF820.

If you are using HTTP proxy, you will need to change the webadmin port to something else (not port 80).