@dfgdfgg 

Hi, most mobile network operators assign private IP or CGNAT IP now which are not public IP address, in that case, the VPN Server on the 4G Router will be behind another NAT, thus remote client will not be able to connect to the VPN Server.

If you really need it, please contact your ISP first to see if they could assign a public IP address.

  @dfgdfgg 

Hi, the FAQ you mentioned is for IPSec site to site VPN, which is kind of different from single VPN Server.

For the IPSec site to site VPN, you will need two VPN Routers on both sites, and at least one of the VPN Routers need to have public IP address.

For other single VPN Server which allows client device to connect directly, such as PPTP VPN Server, OpenVPN Server, they are supported by most of our LTE Gateway Routers as well, but please note that public IP address is necessary. That is why I suggest you to confirm with your mobile network operator whether they could assign public IP address.

Note: As I mentioned, most mobile network operators assign private IP or CGNAT IP address now, but some ISP might still assign public IP address via special APN etc., and most of the TP-Link LTE Gateway routers can also be used as standard wireless router with Ethernet WAN, which usually obtains public IP address. Therefore, it is not deceptive advertising.