@Jeesoon1 My mistake. I gave you the wrong port number. It should be 29810-29814. I Edit my answer and correct it.

@Jeesoon1 You don't need a cloud-based controller, since you already have OC200. The solution is, on the OC200 site's Router, open port 29810-29814 for the controller IP. On the EAP management...

@d0ugmac1 I think the problem is on VLAN interface. The switch may not have an IP interface on VLAN 161 so it won't be managed/available in VLAN 161. The switch default IP is only applied for VLAN 1....

@Didier31 I only test the Standalone mode, when set up OpenVPN server there is Remote Subnets option, and it can cover more than one subnets. I did not really test if it also works for Site-to-Site...

It seems like username/password incrrect. Controller password must be more than 8 letters/characters

@mimamajo Tplink has an article but it may make some misunderstanding. https://www.tp-link.com/us/support/faq/2135/ In this example it use some special IP as WAN public IP, like 88.88.88.88. However...