How to connect clients through external vpn server via tunnel vpn.

[primerump]

I'm a network noob here so please be gentle..

I need to connect remote clients to my office system, due to external restrictions outside my control i can only use port 443 for a vpn tunnel, secondly due to monopoly isp and location issues i have to deal with double NAT at the office end.

I have an external dedicated server with a static ip address setup as an OpenVPN server on port 443 using tcp.
I have configured the clients correctly ( or so i think ! ) and can connect to the vpn server with a client and access the internet without issue. this is working. At the office i setup the Untangle TunnelVPN app to connect to the external server and forward all traffic. I can access the internet and the office can browse without issue. now the part i don't understand is how to form a bi-directional link between the office and client. I'm told by others that this is possible but i can't figure it out.

can anyone please help me here ?

thank you

[jcoffin]

Probably the best solution is to use SD-WAN.

remote PC ----> Unrestricted ISP ---> UT using OpenVPN ---> site to site config client on restricted UT using OpenVPN,